Way back in November of 2011, the library was equipped
with an overridable error message handler function. It
was done expressly for a program like top which alters
the tty. But that support was withdrawn shortly after.
This was all done in the lead up to v3.3.2. That's the
release where NLS support was added and it represented
a hectic time. In hindsight, the changes went too far.
So this commit, in a minimal fashion, restores ability
to address a potential fatal library error. After all,
any properly behaving library would never unilaterally
subject a caller to a stderr message and then an exit.
[ when exposing 1 variable in libprocps.sym, 2 other ]
[ existing symbols were repositioned alphabetically. ]
Reference(s):
. generalized library memory provisions
commit 7126cc4491
. top exploit library memory provisions
commit 88087ec5a5
. library xalloc type functions made private
commit 2865ded64e
. restored prior top memory logic
commit 05f5deb97c
Signed-off-by: Jim Warner <james.warner@comcast.net>
And I thought those strange characters I saw with only
certain translations in Fields Management descriptions
were resulting from my terminal emulator deficiencies.
Turns out that ol' top wasn't addressing possibilities
of such descriptions ending with multi-byte sequences.
Signed-off-by: Jim Warner <james.warner@comcast.net>
Initially, I was going to ignore that coverity warning
CID #177876. But, since top may be running SETUID it's
best if it can be avoided instead. The fix was simple.
We'll trade the access() call for a real fopen() call.
This time-of-check-time-of-use warning should go away.
------------------------------------------------------
When XDG support was originally introduced in top, the
author made a poor choice in access(). A real question
that needed asking was 'does the file exist'. However,
the question that was asked was 'can this real user ID
or this real group ID access the file'. Then, when the
fopen() is finally issued, top would use the effective
user ID or the effective group ID to access that file.
That's what opened the potential TOCTOU vulnerability,
which was important only if top was running SUID/SGID.
Signed-off-by: Jim Warner <james.warner@comcast.net>
By eliminating the call to 'fmtmk', the 'utf8_justify'
function could more easily be used in libproc someday.
Signed-off-by: Jim Warner <james.warner@comcast.net>
Gosh, all this time we used indents of 4 spaces, not 3
spaces which were always the top standard indentation.
[ and we made our 'utf8_embody' a little more robust ]
Signed-off-by: Jim Warner <james.warner@comcast.net>
This patch better exploits short-circuit evaluation in
two 'if' tests. In every case, the 1st of 2 conditions
in each 'if' test must take place but it always proves
true with each iteration for 1 of the 'if' statements.
Thus, the 2nd condition will have to be evaluated too.
By reordering 2 tests in each 'if', we can ensure that
the 2nd condition will then be tested much less often.
Signed-off-by: Jim Warner <james.warner@comcast.net>
Upon reflection, there was absolutely no justification
for that call to strlen() which was then followed by a
call to snprintf(). The latter provides this needed #.
[ also make that 'delta' value a little more visible ]
[ instead of hiding it at the end of a its code line ]
Signed-off-by: Jim Warner <james.warner@comcast.net>
With the help of our Swedish translator, hopefully the
final buglet has now been vanquished in the multi-byte
translation support. This one was a real nasty bugger.
Although it didn't occur with every terminal emulator,
occasionally random text lines were being chopped off.
As it turns out, those terminals were blameless. There
were two separate places in top's show_special routine
where potential multi-byte sequences were inadequately
addressed. Solution: exploit existing utf-8 functions.
[ it also became apparent that the translation hints ]
[ in the top_nls module were deficient. so a special ]
[ caution was added regarding the final line of txt. ]
Reference(s):
https://gitlab.com/procps-ng/procps/issues/68
Signed-off-by: Jim Warner <james.warner@comcast.net>
Unlike the insp_mkrow_raw function the insp_mkrow_utf8
routine is not equipped to print non-ctl, non-printing
characters like '<7f>'. However, technically that very
value currently slips through the cracks. So with this
patch top will now print a space in the unlikely event
a character with the value of 127 is ever encountered.
Signed-off-by: Jim Warner <james.warner@comcast.net>
Since all the necessary utf-8 plumbing is now in place
this commit will extend multi-byte support to user and
group names. Now top will be on a par with the ps guy.
[ plus, it's also my way of showing appreciation for ]
[ all those investments silently made by translators ]
Reference(s):
https://gitlab.com/procps-ng/procps/issues/68
Signed-off-by: Jim Warner <james.warner@comcast.net>
Translatable column headers are supposed to be limited
to no more than 7 characters, even though some columns
are wider than that or even variable width. That value
of 7 is dictated by the Fields Management screen which
will otherwise truncate a column header longer than 7.
Our new utf-8 support did not adequately deal with the
potential need for truncation of column headers should
that limit of 7 be exceeded. This patch corrects that.
[ a few comments were also tweaked just a little bit ]
Signed-off-by: Jim Warner <james.warner@comcast.net>
The previous commit implemented multi-byte support for
the basic top user interaction and display provisions.
This commit completes multi-byte support by addressing
that 'Inspect Other Output' feature (the 'Y' command).
Few people probably exploit this very powerful feature
which allows the perusing of any file or piped output.
And even if nobody uses 'Y', someone will stumble over
it on the help screen and try it out. Assuming top was
not built with INSP_OFFDEMO defined, they'll end up on
the screen our translators have faithfully translated.
Without this patch, such a screen would display with a
bunch of 'unprintable' characters which will then show
in the standard (less-like) way as: '^A', '<C3>', etc.
In other words, those poor screens will be a big mess!
[ this program can even display an executable binary ]
[ while at that same time supporting Find/Find Next. ]
[ imagine, a file with no guarantee of real strings! ]
[ just try a Find using less with such binary files. ]
With this commit, the translated 'Y' demo screens will
now be properly shown, providing no invalid multi-byte
characters have been detected. Should that be the case
then they'll be displayed in that less-like way above.
And, if users go on to fully exploit this 'Y' command,
there is a good chance that a file or pipe might yield
output in a utf-8 multi-byte form. Should that be true
such output will thus be handled appropriately by top.
[ in many respects, this change was more challenging ]
[ than the basic support within the previous commit. ]
[ story of my life: least used = most effort needed. ]
Many thanks to our procps-ng translators which enabled
a proper test of these changed 'Y' command provisions:
. Vietnamese: Trần Ngọc Quân
. Polish: Jakub Bogusz
. German: Mario Blättermann
. French: Frédéric Marchal, Stéphane Aulery
[ and my sincerest apologies too, for my negligence! ]
Reference(s):
https://gitlab.com/procps-ng/procps/issues/68
Signed-off-by: Jim Warner <james.warner@comcast.net>
When this project first began implementing translation
support nearly 6 years ago, we overcame many 'gettext'
obstacles and limitations. And, of course, there were
not any actual translations at the time so our testing
was quite limited plus, in many cases, only simulated.
None of that, however, can justify or excuse the total
lack of attention to top's approach to NLS, especially
since some actual translations have existed for years.
When the issue referenced below was raised, I suffered
immediate feelings of anxiety, doubt and pending doom.
This was mostly because top strives to avoid line wrap
at all costs and that did not bode well for multi-byte
translated strings, using several bytes per character.
I was also concerned over possible performance impact,
assuming it was even possible to properly handle utf8.
But, after wrestling with the problem for several days
those initial feelings have now been replaced by guilt
over any trouble I initially caused those translators.
One can only imagine how frustrating it must have been
after the translation effort to then see top display a
misaligned column header and fields management page or
truncated screens like those of help or color mapping.
------------------------------------------------------
Ok, with that off my chest let's review these changes,
now that top properly handles UTF8 multi-byte strings.
. Performance - virtually all of this newly added cost
for multi-byte support is incurred during interactions
with the user. So, performance is not really an issue.
The one occasion when performance is impacted is found
during 'summary_show()' processing, due to an addition
of one new call to 'utf8_delta()' in 'show_special()'.
. Extra Wide Characters - I have not yet and may never
figure out a way to support languages like zh_CN where
the characters can be wider than most other languages.
. Translated User Name - at some future point we could
implement translation of user names. But as the author
of the issue acknowledged such names are non-standard.
Thus task display still incurs no new multi-byte costs
beyond those already incurred in that escape.c module.
For raising the issue I extend my sincerest thanks to:
Göran Uddeborg
Reference(s):
https://gitlab.com/procps-ng/procps/issues/68
Signed-off-by: Jim Warner <james.warner@comcast.net>
The 'N_fmt' and 'N_txt' macros are interchangeable and
just highlight the 2 str types found in Norm_nlstable.
The change in this patch (strictly cosmetic) was found
during the coding for what will be the next 2 commits.
It has not been squashed into either of those so as to
not muddy up the waters for what was a major refactor.
Signed-off-by: Jim Warner <james.warner@comcast.net>
Until this patch, top falsely assumed that there would
always be some (small) amount of physical memory after
subtracting 'used' and 'available' from the total. But
as the issue referenced below attests, a sum of 'used'
and 'available' might exceed that total memory amount.
I'm not sure if this is a problem with our calculation
of the 'used' amount, a flaw in the kernel 'available'
algorithms or some other reason I cannot even imagine.
Anyway, this patch protects against such a contingency
through the following single line addition of new code
. if (pct_used + pct_misc > 100.0 || pct_misc < 0) ...
The check for less than zero is not actually necessary
as long as the source numbers remain unsigned. However
should they ever become signed, we'll have protection.
[ Most of the changes in this commit simply separate ]
[ a variable's definition from its associated logic. ]
Reference(s):
https://gitlab.com/procps-ng/procps/issues/64
Signed-off-by: Jim Warner <james.warner@comcast.net>
For the past 3 years top has fully honored that locale
LC_NUMERIC setting which impacts his refresh interval.
For the past nearly 5 years top has saved that refresh
value in a locale independent form in his config file.
With this commit we'll intentionally break top so that
a comma or period will be accepted for the radix point
regardless of what that LC_NUMERIC may have suggested.
The current locale LC_NUMERIC will, however, determine
how the delay interval is displayed in the 'd' prompt.
[ This position is better than the approach employed ]
[ by those coreutils 'sleep' and 'timeout' programs. ]
[ Both claim to permit floating point arguments. But ]
[ neither one will accept the comma separator should ]
[ the locale be a country that in fact uses a comma. ]
Reference(s):
https://gitlab.com/procps-ng/procps/merge_requests/50
Prototyped by: Jan Rybar <jrybar@redhat.com>
Signed-off-by: Jim Warner <james.warner@comcast.net>
Ok, I admit it. I'm now tired of cleaning up after me.
This is the 3rd related tweak after that '-1' argument
was originally introduced. And with this patch we will
once again properly honor the '-o' and '-u|U' switches
without a need to be followed by an additional switch.
[ one can follow my unfortunate trail of alterations ]
[ beginning with my most recent fix referenced below ]
Reference(s):
commit 4b44aebd80
Signed-off-by: Jim Warner <james.warner@comcast.net>
While the effective user id would always be present in
each proc_t, thus supporting 'u' filtering, other user
ids would only be present if /proc/$$/status was read.
This commit just puts the 'master' branch top on a par
with the 'newlib' branch when user filtering with 'U'.
Signed-off-by: Jim Warner <james.warner@comcast.net>
With the introduction of a new '1' command line toggle
I have gone and broken a provision of the '-p' command
line switch (pids monitoring). Multiple pids could not
be specified through the use of comma delimited lists.
Thus, this commit simply corrects that newly added bug
which was born in the 'adjustment' commit shown below.
Reference(s):
. adjustment to '-1' implementation
commit 909b37d755
Signed-off-by: Jim Warner <james.warner@comcast.net>
There exists the possibility that a 'putp' call can be
issued before the 'setupterm' invocation has occurred,
as is reflected in a bugzilla report referenced below.
Strangely, such a SEGV isn't always triggered as logic
would suggest it ought to be. I experienced a fault in
these environments with the associated curses version:
. archlinux, procps-ng 3.3.12, ncurses 6.0.20170429
. fedora-25, procps-ng 3.3.10, ncurses 6.0.20160709
. opensuse-42.2, procps-ng 3.3.9, ncurses 5.9.20140201
. gentoo, procps-ng 3.3.12, ncurses 6.0.20150808
. slackw-14.2, procps-ng 3.3.12, ncurses 6.0.20160910
Whereas under these environments there was no problem:
. ubuntu-17.04, procps-ng 3.3.12, ncurses 6.0.20160625
. debian-test, procps-ng 3.3.12, ncurses 6.0.20161126
. mageia-5.1, procps-ng 3.3.9, ncurses 5.9.20140323
[ as an aside, the expected result in the bug report ]
[ is incorrect and should mention the '1' parameter. ]
[ however, until release 3.3.13 when the '1' becomes ]
[ a valid switch, numbers are not detected when used ]
[ with any switch which doesn't require an argument. ]
[ you're welcome to treat that as a separate bugglet ]
Reference(s):
https://bugzilla.redhat.com/show_bug.cgi?id=1450429
Signed-off-by: Jim Warner <james.warner@comcast.net>
The top program already incorporated a modest delay at
startup so that some minimal process cpu history could
be established. However, Summary Area system level cpu
statistic history reflected usage since boot. As such,
unchanging % values would be shown with every restart.
This commit just adopts the same approach used in task
%CPU history for the Summary Area statistics. In other
words, it introduces a 'priming read' at startup as is
found in the newlib implementation for the <stat> API.
Reference(s):
https://gitlab.com/procps-ng/procps/merge_requests/42
Signed-off-by: Jim Warner <james.warner@comcast.net>
This program has always tried to maintain an extermely
robust command line parsing procedure, far more robust
that what's available with the getopt stuff. But, with
the introduction of our first numeric switch it should
have been made even more robust than, in fact, it was.
This commit will now accomplish such a desirable goal.
Reference(s):
. added '1' command line switch
commit 89db82d143
Signed-off-by: Jim Warner <james.warner@comcast.net>
If built without ./configure --disable-modern-top, the
program displays each cpu individually providing there
is sufficient vertical screen real estate. For massive
SMP environments this will necessitate use of a config
file where the cpu summary toggle ('1') could be saved
via the 'W' command. But, an rcfile may not be viable.
So this commit introduces a '1' command line switch to
emulate exactly the effects of the interactive toggle.
And since it is our first numeric switch some existing
parsing logic had to be changed slightly. Such changes
are, in truth, an improvement. For example, instead of
seeing "inappropriate '2'" with ./top -2 we'll now see
the vastly more appropriate error "unknown option '2'.
References(s):
https://gitlab.com/procps-ng/procps/issues/55
Signed-off-by: Jim Warner <james.warner@comcast.net>
In their 3.2.7 version of top, Redhat introduced an -M
switch to automatically scale Summary Area memory data
to avoid truncation (and the resulting '+' indicator).
The procps-ng top does not employ suffixes with memory
data nor does it allow for different scaling with each
separate value. Rather, scaling appears at line start.
If built without ./configure --disable-modern-top, the
Summary Area memory will be scaled at GiB which should
lessen chance of truncation. Otherwise KiB was used to
reflect such memory, increasing the truncation chance.
And while 'W' can be used to preserve some appropriate
scaling value, there are arguments against such rcfile
approaches as cited in the issue and bug report below.
So this commit will bump the Summary Area memory scale
factor from KiB to MiB when using --disable-modern-top
as a concession to that Redhat bug report noted below.
And it also introduces a new command line switch which
can force any desired scaling regardless of the rcfile
or which ./configure option might have been specified.
[ for top's help text we'll show 'E' as if it were a ]
[ switch without arguments in order to keep the help ]
[ text displayable without wrap in an 80x24 terminal ]
[ the man page, however, will show all k-e arguments ]
Reference(s):
https://gitlab.com/procps-ng/procps/issues/53https://bugzilla.redhat.com/show_bug.cgi?id=1034466
Signed-off-by: Jim Warner <james.warner@comcast.net>
After much reflection I've come to the conclusion that
displaying 3 decimal places (usually) when memory data
had been scaled is no longer optimal with today's ever
increasing amounts. And given that not all task memory
fields are the same widths, inconsistencies can easily
arise as illustrated and discussed in the issue below.
Instead of unilaterally reducing the number of decimal
places, this commit will sneak in such a change via an
existing configure option that was very likely unused.
The former 'disable-wide-memory' option has now become
'enable-wide-memory', which can be used if the current
behavior (3 decimal places) is preferred. Without that
option, whenever memory is scaled beyond KiB, just one
decimal place will be shown in Summary and Task areas.
And Task area field width will no longer be changed by
this revised configure option. Instead, all such field
widths will now be fixed at the former maximum values.
Reference(s):
https://gitlab.com/procps-ng/procps/issues/50
Signed-off-by: Jim Warner <james.warner@comcast.net>
By default the file HOME/.toprc will be prefered. This ensures there
should be minimal breakage even if this file is later created by some
other means. Otherwise we will follow the new behaviour described by
the XDG Base Directory Specification:
If the XDG_CONFIG_HOME environment variable is available we will attempt
to use this as XDG_CONFIG_HOME/procps/toprc otherwise we will fall-back
to HOME/.config/procps/toprc instead.
Signed-off-by: Earnestly <zibeon@gmail.com>
That issue cited below prompted some changes under the
newlib branch to standardize the calculation involving
busy, idle, user & system accumulated plus delta tics.
This patch will bring our master branch version of top
into agreement with that newlib version which exploits
some of those newly added library extended provisions.
Reference(s):
https://gitlab.com/procps-ng/procps/issues/48
Signed-off-by: Jim Warner <james.warner@comcast.net>
It makes no sense to begin our tracked nested level at
'1' then later require a '1' to be subtracted from the
level as artwork and indentation is added for display.
By beginning such tracked levels at zero, we can avoid
the need to adjust it & use it directly in a snprintf.
[ this commit parallels a patch in our newlib branch ]
Signed-off-by: Jim Warner <james.warner@comcast.net>
Still unhappy with a minor memory leak associated with
libnuma, I experimented with omitting the dlclose that
was issued at module's end. For some reason which will
remain a mystery, the valgrind leak then went bye-bye.
So this patch just omits one use of dlclose and relies
on whatever kernel magic is at work to free the memory
when each process ends. We kept, however, the original
code (now commented-out) to serve as a future caution.
There remains one potential (but unlikely) dlclose use
near the original dlopen. But there will be no leak as
that 'numa_node_of_cpu' will not yet have been called.
This seems to be the culprit that triggers such leaks.
None of this libnuma shit would likely have come close
to hitting our fan had the numa developers provided us
with 'new' and 'unref' functions like our newlib does.
[ this commit parallels a patch in our newlib branch ]
Signed-off-by: Jim Warner <james.warner@comcast.net>
After discovering those terrible costs associated with
/proc/status vs. /proc/stat, the build_header function
changed to favor the latter for a field found in both.
Well, low-and-behold, this top program still used some
flags that needlessly caused 'status' to still be read
when 'statm' could have served. And, while top's needs
require conversion from pages to KiB, that's still far
less costly than reading that gosh darn 'status' file.
[ this patch parallels similar changes to newlib top ]
Signed-off-by: Jim Warner <james.warner@comcast.net>
Long ago, in a galaxy far away, top was convinced that
/proc/stat was to be favored over /proc/status if some
field could be satisfied with either. This was done to
avoid extra costs of 64-bit math for 32-bit platforms.
Well, its time to acknowledge the prevalence of 64-bit
platforms. And in such an environment there is a large
hidden cost currently if using status instead of stat.
In fact, that cost difference can be as high as 1400%.
So, this commit will coax top into favoring that least
costly route while also fixing an EU_TGD library flag.
[ this patch parallels similar changes to newlib top ]
Signed-off-by: Jim Warner <james.warner@comcast.net>
This commit provides for raising the total displayable
fields from its current 70 to 86. It also bumps the id
in an rcfile representing the version from 'i' to 'j'.
The increase in number of fields will make sharing the
rcfile with an older top, once it's saved, impossible.
These changes are being done via a #define rather than
hard coded so any such sharing will still be possible.
Signed-off-by: Jim Warner <james.warner@comcast.net>
Whoa, I had never considered an alternative to ncurses
until the issue referenced below was raised. Thus, I'm
surprised to find that 'tparm' was the only impediment
to ultimately utilizing this alternate curses library.
And, while we could have substituted that non-standard
'tiparm' with only 2 arguments, we'll utilize the full
parms compliment in the spirit of that original patch.
Frankly, the task of developing an alternative library
to that ncurses implementation really boggles my mind.
Congratulations to rofl0r, whoever that masked man is.
Reference(s):
. issue raised
https://gitlab.com/procps-ng/procps/issues/38
. netbsd-curses home
https://github.com/sabotage-linux/netbsd-curses
Signed-off-by: Jim Warner <james.warner@comcast.net>
This patch adapts the ps program to a newly add proc_t
field and provides for new support in that top program
along with his man document (ps was already ok there).
Signed-off-by: Jim Warner <james.warner@comcast.net>
This development (only) define can be used to turn top
into a simple text program, disabling termcap effects.
But input (at screen bottom) suffers from a line wrap.
So, this commit just makes the input prompt processing
a little more effective by adding one leading newline.
Signed-off-by: Jim Warner <james.warner@comcast.net>
Now that the conditional OOMEM_ENABLE has been removed
and all users exposed to those 'out of memory' fields,
it's about time we added them to the top man document.
Signed-off-by: Jim Warner <james.warner@comcast.net>
Using the <STAT> api under the newlib branch, that top
program is very responsive to changes in the number of
on-line cpus. However under the master branch this top
program is very responsive only to losses of some cpu.
When a cpu is brought back on-line potential delays of
60 seconds could be encountered. That delay was simply
an attempt to reduce costs and reflected the erroneous
assumption that adding a cpu required physical effort.
So without redesigning the cpu refresh code to emulate
that of newlib, this commit just reduces the potential
delay to 3 seconds (the same that is used for memory).
[ As an aside, if one wants to have their confidence ]
[ in that htop program badly shaken, try taking some ]
[ cpus off-line & on-line again while it is running. ]
[ Poor ol' htop just continues to report results for ]
[ whatever were the cpus when started. Nice feature, ]
[ but I wonder where those phantom results are from. ]
Signed-off-by: Jim Warner <james.warner@comcast.net>
This commit just tries to parallel that newlib branch.
It contains the following changes, which were prompted
by the newlib coverity analysis which Craig initiated:
. comment typo predicting 'String not null terminated'
. eliminate 'Logically dead code' from insp_make_row()
Some tweaks, unrelated to coverity, are also included:
. use more modern (recommended) approach for time call
Signed-off-by: Jim Warner <james.warner@comcast.net>
This commit just tries to parallel the implementations
in the newlib branch. The config file Rc.zero_suppress
will be extended to include both out-of-memory fields.
And while we're at it, we'll also extend zero suppress
to that NI (nice value) field, which already should've
had it. Plus we trade those namespaces custom suppress
logic for our now slightly enhanced make_num function.
Signed-off-by: Jim Warner <james.warner@comcast.net>
Since support already exists in the newlib branch this
represents an equivalent master branch implementation,
and this commit message is shared with 2 more patches.
Beginning with linux-4.5, the following new fields are
being added under that /proc/<pid>/status pseudo file:
. RssAnon - size of resident anonymous memory
. RssFile - size of resident file mappings
. RssShmem - size of resident shared memory
p.s. Locked resident memory support was also added but
isn't directly related to the kernel 4.5 enhancements.
p.p.s. Archlinux, Debian-stretch and Fedora-23 already
are currently using a 4.5 linux kernel (as of 6/2/16).
Signed-off-by: Jim Warner <james.warner@comcast.net>
The commit referenced below claims to disable vertical
scrolling when idle tasks weren't being shown. However
it really addresses only a point in time when that 'i'
toggle is keyed. Left untouched were the up/down keys.
So this commit will simply finish the job of disabling
vertical scrolling whenever tasks which have used some
CPU are the only ones which are currently being shown.
Reference(s):
commit c07f6c5e6d
Signed-off-by: Jim Warner <james.warner@comcast.net>
Multiple scanf()s use the GNU-permitted %Lu. This is not supported in
other libraries and isn't to the POSIX specification. The L modifier
is only used for floats in POSIX.
Replacing %Lu with %llu is the same for GNU libc (scanf(3) says as much)
but means other libraries will work fine.
Closes: #19
References:
http://pubs.opengroup.org/onlinepubs/009695399/functions/fscanf.html
It is documented behavior that when certain other keys
are active, sorts column highlighting will temporarily
be disabled. Among those keys is the 'L' (locate/find)
provision. The equals ('=') key can be used to restore
column highlighting by resetting other keys, except 1.
When a locate/find is active, the '=' key will have no
effect on 'x' column highlighting, which still remains
disabled. Further, when 'L' is active an 'x' keystroke
is processed changing the state of column highlighting
but without any visual clue (since it's yet disabled).
So this commit just extends the '=' key to embrace 'L'
processing resets, just like other highlight disabling
keys while avoiding 'x' state changes if approproiate.
Signed-off-by: Jim Warner <james.warner@comcast.net>
We'll following the newlib <pids> approach to hashing:
. a 'PIDs at max depth:' portion of that UNREF_RPTHASH
enabled #define is now published only when the maximum
depth of hash table entry chains exceed depths of one.
Signed-off-by: Jim Warner <james.warner@comcast.net>
Craig's recent commit under that newlib branch dealing
with namespace support has prompted me to review top's
handling of those fields. Currently, when such a field
is zero, top displays a dash ('-'). This will mean the
justification toggles ('j/J') will behave incorrectly.
This patch simply allows the potential zero to display
or be suppressed with the already existing '0' toggle.
Signed-off-by: Jim Warner <james.warner@comcast.net>
A patch containing the following miscellaneous tweaks:
. remove a function that handled former library errors
[ that function should have gone bye-bye with 3.3.11 ]
[ when those 'wchan' provisions were much simplified ]
Signed-off-by: Jim Warner <james.warner@comcast.net>
While testing a newlib interface for pids acquisitions
I encountered some unexpected results if an idiot user
(me) turns off all displayable fields. So, this commit
ensures that the PID field will be shown as a minimum.
Signed-off-by: Jim Warner <james.warner@comcast.net>
When the USED column was introduced the proc_t.vm_swap
& proc_t.resident values were added together. However,
using 'resident' required an additional PROC_FILL flag
not to mention extra conversion of pages to kibibytes.
So now we'll use an already present vm_rss value which
removes any special handling for top's derived column.
And while we're at it we'll trade some more 'resident'
field uses with that more immediately usable 'vm_rss'.
Reference(s):
commit 709785e20b
Signed-off-by: Jim Warner <james.warner@comcast.net>
Jeeze, to correct spelling on one single word (incure)
you had to go and align the entire comments paragraph?
[ well, at least there's one other minor code change ]
Signed-off-by: Jim Warner <james.warner@comcast.net>
Since it's possible that euser name is not being shown
or the horizontal position had been scrolled past that
USER column, then part of those headers will be blank.
So it doesn't make sense to try and show the USER that
is associated with a process at all. Thus, this commit
simply removes the 'user' provision from both headers.
Signed-off-by: Jim Warner <james.warner@comcast.net>
When a user is taking advantage of the scroll features
it is likely a scrolled vertical position is well past
the first displayable task. That is especially true of
top's forest view ('V') mode where those early systemd
attached processes are generally not very interesting.
As such, should the idle mode toggle ('i') be employed
a distorted display is almost guaranteed because tasks
that have used some cpu, and thus should be displayed,
have already been skipped by virtue of their position.
So this patch temporarily nullifies vertical scrolling
during the period when idle tasks are not being shown.
Signed-off-by: Jim Warner <james.warner@comcast.net>
With the commit referenced below, the linux version is
no longer available via an external variable. So we'll
eliminate the extra superficial function call employed
at program end as part of a debugging (only) o/p spew.
[ the user will soon be returned to the command line ]
[ & he/she can run their own 'uname -r' if in doubt! ]
Reference(s):
commit 56d9d5e7e7
Signed-off-by: Jim Warner <james.warner@comcast.net>
Added function procps_linux_version() which used to be an
exported integer instead. Also changed the method of obtaining
the linux version (more correctly the os release) to use a specific
procfs entry. This works for both Linux and FreeBSD.
This patch was made necessary by those library changes
in support of recently revised/simplified wchan logic.
Reference(s):
http://www.freelists.org/post/procps/WCHAN,11
Signed-off-by: Jim Warner <james.warner@comcast.net>
It doesn't make any sense to have the binary version strings
embedded into the library. The version strings are defined
already either in the Makefile or in include/c.h
This commit just tweaks top in the following respects:
. for alphabetic integrity, change 'INSP_hdr...' names
. eliminate the -Wsometimes-uninitialized warning that
was found under OSX Yosemite (llvm 6.0/clang-600.0.56)
. update program 'comments' reflecting copyright dates
Signed-off-by: Jim Warner <james.warner@comcast.net>
A recent commit eliminated the potential for a storage
violation with forest view mode. It occurred when some
program (erroneously?) created a lengthy forking loop.
However, the associated commit message was misleading.
The message implied that an unexpected order following
a sort on start_time was the cause of storage overruns
and a 'char' used to track nesting level only distorts
the display when it goes negative. Actually, the truth
is really just the opposite. Any start_time sort quirk
causes no harm while that 'char' can yield corruption.
Should some child end up sorted ahead of its parent by
way of an extremely unlikely shared start_time the end
result is such a child will be displayed unnested just
like init or kthreadd along with all its own children.
However, if nesting levels exceeded 255 (and became 0)
a massive array overrun could be triggered when such a
task and *all* its children were added to an array for
the second time. Exactly how much storage was violated
depended on the number of children that zeroed process
had spawned (hinted at via either SIGSEGV or SIGABRT).
The earlier commit limited nested levels to 100 so the
root cause of the storage violation was already fixed.
The potential for distorted nesting levels due to sort
on start_time would seem to remain. But it's extremely
unlikely that 2 tasks would share the same start_time.
Even so, a new #define has been introduced which makes
top impervious to the order of tasks such that a qsort
is no longer necessary (providing an init/systemd task
exists & was harvested as the first task by readproc).
It can be utilized if distorted nesting ever becomes a
real issue. But since there is a 5-10% performance hit
with that, we'll continue using start_time as default.
References(s):
commit ce70017eb1
Signed-off-by: Jim Warner <james.warner@comcast.net>
This commit will eliminate a very nasty bug associated
with top's forest view mode. It addresses a potential
SIGSEGV/SIGABRT that was only encountered when another
program (erroneously?) creates a lengthy forking loop.
If the growing list of nested children is sufficiently
fast such that proc_t start_time is duplicated between
children then the sort upon which top relies might not
produce the expected order. That, in turn, could cause
the forest_adds function to initially miss some child.
But that missed child would be caught by forest_create
and eventually would cause our array boundary overrun.
Such overrun occurs when some child of that originally
*missed* child is found and a duplicate add attempted.
In correcting this bug we'll also use this opportunity
to prohibit a borrowed proc_t padding byte (char) from
going negative. If the nesting level exceeded 127, the
effect was an "unnesting" with the snprintf width then
viewed as flag+width also yielding left justification.
Henceforth, we'll limit nesting to 100 with subsequent
children shown as " + ", not the usual " `- " prefix.
References(s):
https://bugzilla.redhat.com/show_bug.cgi?id=1153642http://www.freelists.org/post/procps/Bug-in-the-forrest-view,6
Signed-off-by: Jim Warner <james.warner@comcast.net>
When startup defaults were changed users with existing
rcfiles would likely find their previous configuration
was not being honored in all respects. The disparities
involved Graphs modes and Summary/Task memory scaling.
This patch simply restores what was always intended as
the proper behavior for previously saved config files.
References(s):
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=762928https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=762947
. new startup defaults
commit 8ef6cd91fc
Signed-off-by: Jim Warner <james.warner@comcast.net>
This patch will cure a potential aberration associated
with a terminal's size (SIGWINCH) and top's new graphs
modes. The symptoms were a dangling tilde (~) plus the
potential loss of a graph's right-most visual content.
The condition was only apparent when a %Cpu approached
100% usage. Also the apparent loss of content affected
the 'block' graph only. With 'bar' graphs, that affect
became the loss of proper right-most bar graph colors.
The cause was determined to be a combination of: 1) an
unnecessary snprintf precision specification; and 2) a
rounding quirk for any graphs which displayed distinct
types of information (as for user/syst, used/unavail).
These could then combine to produce an extra bar/block
which, in turn, resulted in the truncation of a pseudo
termcap attribute used by the show_special() function.
What was originally interpreted as an intractable race
condition turns out to be just a self inflicted wound.
Reference(s):
http://www.freelists.org/post/procps/top-Possible-bug-in-the-graphs,1
Signed-off-by: Jim Warner <james.warner@comcast.net>
This patch will trade a former pessimistic calculation
of free physical memory for a more optimistic one that
uses the newly added kb_main_available library export.
But in case one might wish to return to the old former
method, there's a new #define that was made available.
[ the new calculation will affect graphing mode only ]
Reference(s):
http://www.freelists.org/post/procps/systemd-support-to-library,9
Signed-off-by: Jim Warner <james.warner@comcast.net>
Might as well use the newly exposed sysinfo.h variable
'page_bytes' rather than our own. Plus, in the process
we can avoid incurring yet one more function call hit.
Signed-off-by: Jim Warner <james.warner@comcast.net>
Gosh, just because most of us might run with some swap
file allocated, not every system might. I only wish my
testing methodology was as sophisticated as Jaromir's.
Reference(s):
http://www.freelists.org/post/procps/latest-top-enhancements,7
Signed-off-by: Jim Warner <james.warner@comcast.net>
When startup argument parsing was recently enhanced to
account for LC_NUMERIC settings, some user input logic
dealing with numbers fails to exploit that capability.
This patch extends such enhancements to a running top.
Reference(s):
commit f7b84f45c7http://www.freelists.org/post/procps/topwatch-floating-point-input,2
Signed-off-by: Jim Warner <james.warner@comcast.net>
When those new cpu/memory graphs modes were introduced
they had global impact. In other words, the modes that
were chosen for a 'current' window affect Summary Area
appearance for every other window as well, even though
each window sets unique View_STATES/View_MEMORY flags.
I do not know how widespread the use of top's separate
window provisions is, but I do know that documentation
promises every window (field group) provides "a unique
separately configurable summary area". And even though
that promise does not include memory scaling (separate
'E' command) the graph modes are integral to 't' & 'm'
and those were already observed on a per window basis.
So this patch just takes the cpu and memory graph mode
values out of global scope in the configuration file &
gives each window its own unique pair of graph values.
Reference(s):
commit 1d171ec741
Signed-off-by: Jim Warner <james.warner@comcast.net>
Boy I hate locale stuff. For code I thought was pretty
robust, Jaromir sure proved that it wasn't. Anyway, me
thinks this commit closes some gaps and will cause top
to behave appropriately under various locale settings.
It does *not* permit top to respond to the ',' and '.'
floating point separator without regard to the locale.
It does, however, enforce proper LC_NUMERIC responses.
Let's look on this commit as an interim solution until
Jaromir can create that proposed 'fp_decode' function.
Who knows, he might even borrow some of our mkfloat().
[ An aside: the coreutils sleep and timeout programs ]
[ claim to permit floating point arguments. However, ]
[ neither one will accept the comma separator should ]
[ the locale be a country that in fact uses a comma. ]
[ In other words, with this commit we are way ahead! ]
Reference(s):
http://www.freelists.org/post/procps/topwatch-floating-point-inputhttp://www.freelists.org/post/procps/topwatch-floating-point-input,1
Signed-off-by: Jim Warner <james.warner@comcast.net>
While there was no harm done setting a handler for the
above two signals, they are in fact uncatchable. Thus,
whenever we ran with valgrind we're politely reminded.
Signed-off-by: Jim Warner <james.warner@comcast.net>
When the beginning of the Mem/Swap graphs was variable
scaling them to the current terminal's width was a bit
of a costly nightmare. So the graph size was fixed and
subject to truncation. However now that the start of a
graph can be easily predicted, I've revisited scaling.
As it turns out, any cost is minimal & mostly incurred
at an opportune time, at SIGWINCH or user interaction.
Plus, most of the apparent arithmetic is actually just
a means of documenting and will disappear thru compile
time constants in the ultimate generated machine code.
Note: those graphs will now behave just like any other
Summary Area element - they will scale from full sized
down to a terminal width of 80 columns, at which point
those displayed graphs are then subject to truncation.
Signed-off-by: Jim Warner <james.warner@comcast.net>
While the 'b' toggle remains window based (vs. global)
it should no longer require that the window be visible
and either the 'x' or 'y' toggles to be on. Previously
those requirements were intended to remind a user that
there must be something for this command to highlight.
With the introduction of graph modes (specifically the
the bar graph) the 'bold/reverse' toggle has important
implications beyond highlighting some columns or rows.
The %Cpu(s) graph and Mem portion of the memory graphs
are designed to offer a visual clue as to the separate
elements comprising them. But that separation could be
lost under some X color schemes or when top is running
without color (in monochrome mode) and the block graph
is selected. But, if the graph is then changed to bars
any separation always becomes visible whenever the 'b'
toggle is turned off. Portions then show in 'reverse'.
So from now on we'll check nothing, we'll just toggle.
[ Besides, with all the code thrown at restricting a ]
[ 'b' toggle use, it might have all been for naught. ]
[ That toggle could still be set/unset using the 'Z' ]
[ command and the color mapping screen. Geez Louise! ]
Signed-off-by: Jim Warner <james.warner@comcast.net>
My original graph modes implementation made no attempt
to align the Cpu & Mem/Swap graphs. I thought, rather,
that such alignment could be best achieved by the user
using top's 'E' memory scaling command toggle. In that
way Mem/Swap prefixes could be reduced by 3 positions,
bringing the beginning '[' into line with the %Cpu(s).
If that proved to be too cumbersome a #define could be
enabled making the Mem/Swap prefix static while adding
a few padding bytes to the %Cpu line(s) for alignment.
It was those waisted bytes that were the most concern.
What I had not counted on was the fact that the memory
lines themselves might become misaligned & that became
likely with more physical memory present. That too can
be cured with the 'E' command but as scaling is raised
we soon reach a meaningless total such as '0.003' even
though the displayed % remains valid (and unchanging).
So this commit implements unconditionally what used to
be conditional. But, instead of waisting padding bytes
we'll put that space to good use with a new 'total %'.
Reference(s):
http://www.freelists.org/post/procps/latest-top-enhancements,1
commit 1d171ec741
Signed-off-by: Jim Warner <james.warner@comcast.net>
My first blush graphs modes implementation went just a
tad overboard on identifier lengths. As a result, some
program lines were getting quite long. So, this commit
will simply shorten some excessively long identifiers.
Reference(s):
http://www.freelists.org/post/procps/latest-top-enhancements
commit 1d171ec741
Signed-off-by: Jim Warner <james.warner@comcast.net>
This patch makes 't' (View_STATES) & 'm' (View_MEMORY)
commands into 4-way toggles. The two new modes provide
for two different graphs of the cpu and/or memory use.
These new capabilities are similar to those offered by
the 'htop' program. However they're aesthetically more
pleasing (to me) plus the scalings are more authentic.
Poor ol' top has long been troubled by the comparisons
offered up by the 'htop' program. Many of those things
were only true of the original redhat top while others
are no longer true of this current top program. So let
me use this commit msg to begin to correct the record.
Corrected comparisons between 'htop' & 'top' programs:
------------------------------------------------------
+ htop does not start faster, actually reverse is true
+ top offers scrolling vertically and horizontally too
. (and top offers better <Home> and <End> key support)
+ unassigned keystrokes don't subject top to any delay
. (but htop suffers that annoying ncurses <Esc> delay)
+ in top one need not type the PID to kill the process
+ in top one need not type the PID to renice a process
Some things the 'htop' program was not bragging about:
------------------------------------------------------
+ top can outperform the htop program by a wide margin
+ htop + SIGWINCH = corrupted display + restart likely
+ htop cannot preserve its screen data at suspend/exit
+ the htop column management scheme is very cumbersome
+ htop allows columns to be duplicated again and again
+ htop displays only full command lines, not pgm names
. (and that 'Command' column must always be displayed)
. (and it must always remain as the last column shown)
+ htop does not provide for any sort of command recall
+ htop's search feature does not highlight any matches
+ there is no 'find next' outside of htop search modes
+ htop does not allow Header or Process memory scaling
+ htop provides no flexibility on column justification
+ htop does not provide the means to change col widths
+ htop provides less control over colors configuration
+ htop always overwrites the rcfile with any UI change
Someday, maybe we'll provide a better comparison as an
addendum for (or replacement of) that README.top file.
Signed-off-by: Jim Warner <james.warner@comcast.net>
In anticipation of upcoming memory graphing provisions
the abbreviations 'Mem' and 'Swap' are being made into
individual translatable strings in order to be reused.
Additionally, the Mem 'used' amount will now no longer
included the 'buffers' and 'cached' values. Thus, each
Mem category becomes unique. This is the approach used
by tools such as 'htop' or the gnome 'System Monitor'.
Lastly, with that change to the 'used' category it has
been repositioned after 'free' on the Mem & Swap lines
making a comparison between 'total' and 'free' easier.
Signed-off-by: Jim Warner <james.warner@comcast.net>
For some time now, top has refrained from updating the
current number of cpus and memory totals with each and
every refresh cycle. Rather, to lessen overhead costs,
such values are updated periodically (5 min & 3 secs).
The delay in updating the cpu count was only important
with the addition of a cpu, since any loss is detected
immediately. And the large interval was chosen because
of the costs once associated with a glibc sysconf call
and an unlikely scenario of physically adding the cpu.
But the ease with which cpus can be taken offline then
placed back online under linux suggests that 5 minutes
may be too high. So, without addressing the likelihood
of that act, top is now more responsive in these ways:
1) that 5 minute interval has been reduced to 1 minute
2) any key, not just Enter/Space, refreshes cpus & mem
Note: we leave the man document as is, suggesting that
only the Enter/Space keys force an update for hotplug.
Signed-off-by: Jim Warner <james.warner@comcast.net>
. prevent any input recall overrun if window downsized
. adjust translation notes for true column hdr maximum
Signed-off-by: Jim Warner <james.warner@comcast.net>
In release 3.3.6, some commands were equipped with the
concept of a 'default pid'. The initial implementation
meant that the intuitive <Esc> key would not always be
treated as one would expect under any well behaved UI.
This patch ensures the expected <Esc> key behavior of:
terminating user input while still making possible the
necessary distinction between 'no input' & 'defaults'.
Reference(s):
http://www.freelists.org/post/procps/top-Escape-doesnt-abort-kill-command
Signed-off-by: Jim Warner <james.warner@comcast.net>
The granularity of /proc/uptime is fixed at hundredths
of a second. And, since we can cycle faster than that,
we are exposed to 'nan' when calculating elapsed time.
This commit will protect us from that outcome when the
delay interval has been set to an extremely low value.
Signed-off-by: Jim Warner <james.warner@comcast.net>
If a system's time is adjusted backwards, then elapsed
time could appear as negative. This yielded a negative
%CPU value. Alternately if zeros were suppressed ('0')
the result was a blank %CPU column. In both cases that
distortion would last for one display cycle or until a
user forced a display refresh via some keyboard input.
The original recommendation was trading gettimeofday()
for clock_gettime() using CLOCK_MONOTONIC. But on some
systems that might not be possible, forcing the use of
CLOCK_REALTIME instead. Not only would that complicate
the build system, but it may leave us with minus %CPU.
Another approach was to ensure that elapsed time could
never be negative. Of course, this produced distortion
of %CPU values but it would be proportionally correct.
This wasn't dissimilar to a distortion already present
should the time be adjusted forward or backward within
any 'remaining' top delay intervals. These aberrations
would be avoided with clock_gettime & CLOCK_MONOTONIC,
but that is a less than ideal solution as noted above.
This final solution, which originated down under, will
simply rely on the /proc/uptime seconds, which will be
immune to *any* tampering with the system clock. Thus,
we now have a fix for the distortion we didn't know we
suffered plus a negative %CPU that began this odyssey.
Thanks to:
sk.alvin.x@gmail.com, for the original effort
jcapik@redhat.com, for a heads up on CLOCK_MONOTONIC
csmall-procps@enc.com.au, for the best suggestion of all
Reference(s):
. original post/patch
http://www.freelists.org/post/procps/PATCH-top-use-clock-gettime-instead-of-gettimeofday
. heads up on CLOCK_MONOTONIC
http://www.freelists.org/post/procps/PATCH-top-use-clock-gettime-instead-of-gettimeofday,2
. the final solution
http://www.freelists.org/post/procps/PATCH-top-use-clock-gettime-instead-of-gettimeofday,11
Signed-off-by: Jim Warner <james.warner@comcast.net>
Minor fixes that the translator (Yuri) has found in some of the
strings. You only know how many typos and thinkos you have when
someone is trying to translate it.
Signed-off-by: Craig Small <csmall@enc.com.au>
Since its inception top has always used enumerators to
identify displayable fields. They've taken the form of
P_PID, etc. As it turns out, something has changed for
libc6-dev versions beyond 2.17-93 wherein 'P_PID' will
now be exposed via stdlib.h. I have not pinpointed the
exact cause but it may depend on header include order.
This patch just trades top's long standing 'P_' prefix
convention for that of 'EU_' (short for enumerator). I
cannot find *any* header under /usr/include/ currently
utilizing this particular three character combination.
And as a further safeguard top will henceforth include
'system' specific headers after the standard includes.
Reference(s):
http://www.freelists.org/post/procps/top-wont-compile-anymore
Signed-off-by: Jim Warner <james.warner@comcast.net>
When top originally responded to the potential libnuma
stderr write, the library was consistently called with
each refresh cycle. That, in turn, guaranteed that any
warning message would be seen at program end by virtue
of: 1) having been issued before the 2nd refresh cycle
and; 2) benefiting from inherited /dev/null buffering.
A later efficiency refactor meant the numa library may
not always be called with every refresh cycle. Rather,
it was only called if top was in one of two numa views
(the '2' or '3' toggles). That, in turn, resulted in a
loss of any warning message at program end unless numa
mode had been preserved in the rcfile. In other words,
if top was started normally then a single cycle stderr
redirect would have long passed by the time the '2' or
'3' toggle was activated. The warning message actually
was spewed but quickly lost to the full screen refresh
which follows all keyboard interactions with the user.
This commit simply moves the restoration of our stderr
redirect to program end (instead of that first display
refresh). Now, any libnuma stderr warning message will
appear as the concluding output line upon quitting top
without regard to when any numa mode view was invoked.
And since this technique might be useful in some other
context (as an example of how to 'buffer' stderr) it's
been generalized with its own #define. But to maximize
its usefulness, the original redirect should be issued
much earlier in pgm startup than top has chosen to do.
Reference(s):
. original libnuma stderr response (msg seen)
commit 35dc6dcc49
. numa refractoring for efficiency (msg lost)
commit f12c0d5c6e
Signed-off-by: Jim Warner <james.warner@comcast.net>
Apparently there are occasions when NUMA nodes may not
always be contiguous. Under such conditions nodes that
were not used would still occupy precious Summary Area
space showing 100% idle, under the '2' command toggle.
With this commit top will no longer display numa nodes
that have no associated cpu when the '2' toggle is on.
But just in case we wish to return to former behavior,
a new #define called OFF_NUMASKIP has been introduced.
And as an aside, a recent refactor mentioned below set
the stage for this patch to be 'self-tuning'. In other
words, if an inactive/non-displayed node should become
active (if even possible), then top will begin showing
such a node automatically with the next screen update.
Unfortunately, all inactive nodes now 'suppressed' are
still accessible via the '3' command. Those nodes will
just be displayed as empty (no associated cpus shown).
This is not really a top problem but more of a libnuma
and/or user deficiency. The library lacks the means to
validate a node id and the user then input a node that
was not even shown under a '2' toggle Summary display.
( too bad libnuma does not offer an 'is_node_active' )
( type function so top could warn a user when such a )
( discontinuous node was requested using his '3' cmd )
( sure, top could achieve this objective himself but )
( that would require making yet another array global )
( which i'm just not in the mood to do - besides, we )
( have already made enough concessions to libnuma.so )
Lastly, an existing #define (PRETEND_NUMA) was changed
to 'disable' node #1 so as to simulate a discontinuous
node. This allows testing of the '2' and '3' commands.
Reference(s):
http://www.spinics.net/lists/util-linux-ng/msg08671.html
. set stage for self tuning
commit f12c0d5c6e
Signed-off-by: Jim Warner <james.warner@comcast.net>
A recent change involving a one cycle stderr redirect,
to handle a libnuma potential transgression, failed to
follow normal global variable naming conventions. This
patch will capitalize the 1st letter of 'Stderr_save'.
Reference(s):
commit 35dc6dcc49
Signed-off-by: Jim Warner <james.warner@comcast.net>
Excluding those special X_XON/X_XOF enums, which might
not even be present, restore strict collating order of
all the case labels in the task_show switch statement.
Also, adjust a few sort callbacks for the same reason.
Signed-off-by: Jim Warner <james.warner@comcast.net>
The recent addition of namespaces, combined with those
potential suse out-of-memory fields, means that we are
close to the maximum number of fields poor ol' top can
display. Imagine, the really old top was limited to 26
fields (28 with the suse hack) and this top had neared
the version 'g' rcfile limits which were a healthy 55.
This patch adds another 15 fields to the maximum while
making it even easier to increase in the future. Also,
top still silently accommodates older config files all
the way back to the original pre-ng version top-3.2.8!
Signed-off-by: Jim Warner <james.warner@comcast.net>
This patch is inspired by the 'minimize numa overhead'
patch. It trades the use of subscripts for pointers to
avoid gcc repeated subscript offset calculation bloat.
Now, throughout the cpus_refresh function, a subscript
will be resolved just once & this will (dramatically?)
reduce the path-length taken for each and every frame!
For example, a non-optimized compilation could produce
400+ fewer machine instructions through pointer usage.
[ ok, optimized compiles only save 18+ instructions! ]
Lastly, any residual 'symmetry only' crap is now gone!
Signed-off-by: Jim Warner <james.warner@comcast.net>
A recent libnuma potential corruption problem solution
has caused me to reevaluate some associated numa logic
for efficiency. Here is a summary of the problems that
exist with current libnuma/user possible interactions:
. Whenever the numa library was present extra overhead
would always be incurred in maintaining the node stats
even when the '2' or '3' commands were not being used.
. As part of such overhead a separate loop was used to
reinitialize each cpu/node structure with each display
cycle so that prior accumulated totals were preserved.
Again, it didn't matter if numa data was really shown.
This commit attempts to refocus on the 'critical path'
costs in a running top by optimizing for the occasions
when numa node data is not being displayed. Under such
conditions, no extra overhead will be incurred whether
or not a distribution has the libnuma library present.
To achieve this goal, some additional overhead will be
incurred, but only when actually displaying numa data.
And all such new costs have been minimized in spite of
the gcc inclination to duplicate subscript resolution.
Reference(s):
commit 24bd950cb2e1722d459461f0f9c0c30a4b9ffdaa
Signed-off-by: Jim Warner <james.warner@comcast.net>
A recent libnuma potential corruption problem solution
suggests that libnuma could change in the future so as
to not spew to stderr. This then raises a question how
top could exploit any such library change since we are
currently locked into version #1 of the library by way
of our dlopen("libnuma.so.1", RTLD_LAZY) runtime call.
While not an ultimate solution, this commit will first
try for the most recent version of that library during
top's startup before trying the original libnuma.so.1.
We do this via the unqualified library soname symlink.
For this new dlopen() call to succeed, technically the
numa 'devel' package would usually have been required,
but that's not always true with every distro. And when
the libnuma.so symlink isn't present, it can always be
manually added should a newer & better behaved library
arrive & users tire of the stderr warning at top exit.
Reference(s):
commit 24bd950cb2e1722d459461f0f9c0c30a4b9ffdaa
Signed-off-by: Jim Warner <james.warner@comcast.net>
