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top: parent total cpu includes collapsed children, pgm

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Now, when a parent's children have been collapsed, the
cpu used by those unseen tasks will disappear no more.
Instead such tics will be added to the parent's total.

[ if one wished a return to the 'land of lost tics', ]
[ the '#define TREE_VCPUOFF' directive is available. ]

------------------------------------------------------
Note: With collapsible parents now displaying children
cpu usage, it will eventually be noticed the cpu stats
for the summary area and task areas often vary widely.

It's worth a reminder that for top's summary area each
individual cpu and the cpu summary is limited to 100%,
regardless of how many tics a linux kernel may export.

An individual task is limited to 100% times the number
of threads. But, in no case will cpu usage ever exceed
100% times total number of processors. Such limits are
further reduced under 'Solaris' mode ('I' toggle off).
In this mode, a task cpu usage will never exceed 100%.
These limits will now also apply to collapsed parents.

In addition to those influences, results are subjected
to kernel timer sampling anomalies and the distortions
inherent in a small sample size, made worse by smaller
delay intervals. Often there is just 1 or 2 tics for a
few tasks at smaller intervals such as: 1/10th second.

Anyway, should questions on this subject arise, a good
starting point, beyond the reminders above, is the 1st
link listed below. Those other links were derivatives.

Reference(s):
. from the kernel documentation
https://www.kernel.org/doc/Documentation/cpu-load.txt
. as mentioned in the above kernel documentation
https://lkml.org/lkml/2007/2/12/6
. from above, with many more links on the subject
https://www.boblycat.org/~malc/apc/

Signed-off-by: Jim Warner <james.warner@comcast.net>
This commit is contained in:
Jim Warner 2018-06-25 00:00:00 -05:00 committed by Craig Small
parent 6658492df6
commit 7c7903e50d
2 changed files with 41 additions and 19 deletions
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59
top/top.c
View File

@ -1659,12 +1659,14 @@ static struct {
#define eu_TIME_START eu_LAST +3
#define eu_ID_FUID eu_LAST +4
#define eu_LVL eu_LAST +5
#define eu_HID eu_LAST +6
#define eu_ADD eu_LAST +6
#define eu_HID eu_LAST +7
{ -1, -1, -1, -1, PIDS_CMDLINE }, // str ( if Show_CMDLIN )
{ -1, -1, -1, -1, PIDS_TICS_ALL_C }, // ull_int ( if Show_CTIMES )
{ -1, -1, -1, -1, PIDS_TIME_START }, // ull_int ( if Show_FOREST )
{ -1, -1, -1, -1, PIDS_ID_FUID }, // u_int ( if a usrseltyp )
{ -1, -1, -1, -1, PIDS_extra }, // u_int ( if Show_FOREST )
{ -1, -1, -1, -1, PIDS_extra }, // u_int ( if Show_FOREST )
{ -1, -1, -1, -1, PIDS_extra } // s_ch ( if Show_FOREST )
#undef A_left
#undef A_right
@ -1822,7 +1824,7 @@ static void build_headers (void) {
// for 'busy' only processes, we'll need elapsed tics
if (!CHKw(w, Show_IDLEPS)) ckITEM(EU_CPU);
// with forest view mode, we'll need pid, tgid, ppid & start_time...
if (CHKw(w, Show_FOREST)) { ckITEM(EU_PPD); ckITEM(EU_TGD); ckITEM(eu_TIME_START); ckITEM(eu_LVL); ckITEM(eu_HID);}
if (CHKw(w, Show_FOREST)) { ckITEM(EU_PPD); ckITEM(EU_TGD); ckITEM(eu_TIME_START); ckITEM(eu_LVL); ckITEM(eu_ADD); ckITEM(eu_HID); }
// for 'cumulative' times, we'll need equivalent of cutime & cstime
if (Fieldstab[EU_TME].erel > -1 && CHKw(w, Show_CTIMES)) ckITEM(eu_TICS_ALL_C);
if (Fieldstab[EU_TM2].erel > -1 && CHKw(w, Show_CTIMES)) ckITEM(eu_TICS_ALL_C);
@ -4199,9 +4201,8 @@ static void wins_stage_2 (void) {
/*
* Determine if this task matches the 'u/U' selection criteria
* for a given window -- it is called from only one place, and
* will likely be inlined even without the following directive */
* Determine if this task matches the 'u/U' selection
* criteria for a given window */
static inline int wins_usrselect (const WIN_t *q, struct pids_stack *p) {
// a tailored 'results stack value' extractor macro
#define rSv(E) PID_VAL(E, u_int, p)
@ -4238,8 +4239,8 @@ static int Tree_idx; // frame_make resets to zero
positive pid values represent parents with collapsed children
while a negative pid value means children have been expanded.
( both of these are managed under the 'keys_task()' routine ) */
static int *Hide_pid; // collapsible process array
static int Hide_tot; // total used in above array
static int *Hide_pid; // collapsible process array
static int Hide_tot; // total used in above array
/*
* This little recursive guy is the real forest view workhorse.
@ -4300,34 +4301,45 @@ static void forest_begin (WIN_t *q) {
forest_adds(i, 0); // add a parent with its children
}
/* we're employing a couple of 'PIDS_extra' results in our stacks
eu_LVL (u_int): where level number is stored (0 - 100)
/* we're employing 3 additional 'PIDS_extra' results in our stacks
eu_LVL (u_int): where a level number is stored (0 - 100)
eu_ADD (u_int): where children's accumulated tics stored
eu_HID (s_ch) : where 'x' == collapsed and 'z' == unseen */
for (i = 0; i < Hide_tot; i++) {
#define rSv_Pid(X) PID_VAL(EU_PID, s_int, Tree_ppt[X])
// if xtra-procps-debug.h active, can't use PID_VAL with assignment
#define rSv_Lvl(X) Tree_ppt[X]->head[Fieldstab[eu_LVL].erel].result.u_int
#define rSv_Add(X) Tree_ppt[X]->head[Fieldstab[eu_ADD].erel].result.u_int
#define rSv_Hid(X) Tree_ppt[X]->head[Fieldstab[eu_HID].erel].result.s_ch
/* next isn't needed if TREE_VCPUOFF was defined, but it costs us nothing
yet we must never assume that PIDS_CPU result struct is always present */
#define rSv_Cpu(X) (Fieldstab[EU_CPU].erel < 0) ? 0 : PID_VAL(EU_CPU, s_int, Tree_ppt[X])
if (Hide_pid[i] > 0) {
for (j = 0; j < PIDSmaxt; j++) {
if (rSv_Pid(j) == Hide_pid[i]) {
int idx = j;
unsigned lvl = rSv_Lvl(idx);
rSv_Hid(idx) = 'x';
while (j+1 < PIDSmaxt && rSv_Lvl(j+1) > lvl) {
int parent = j;
int children = 0;
unsigned level = rSv_Lvl(parent);
while (j+1 < PIDSmaxt && rSv_Lvl(j+1) > level) {
#ifndef TREE_VCPUOFF
rSv_Add(parent) += rSv_Cpu(j+1);
#endif
rSv_Hid(j+1) = 'z';
idx = 0;
children = 1;
++j;
}
// no children found, so unmark this puppy
if (idx) rSv_Hid(idx) = '\0';
// children found (and collapsed), so mark that puppy
if (children) rSv_Hid(parent) = 'x';
}
}
}
#undef rSv_Pid
#undef rSv_Lvl
#undef rSv_Add
#undef rSv_Hid
#undef rSv_Cpu
}
} // end: !Tree_idx
memcpy(Seed_ppt, Tree_ppt, sizeof(void*) * PIDSmaxt);
@ -5480,8 +5492,9 @@ static const char *task_show (const WIN_t *q, struct pids_stack *p) {
char *rp;
int x;
/* we're employing a couple of 'PIDS_extra' results in our stacks
eu_LVL (u_int): where level number is stored (0 - 100)
/* we're employing 3 additional 'PIDS_extra' results in our stacks
eu_LVL (u_int): where a level number is stored (0 - 100)
eu_ADD (u_int): where children's accumulated tics stored
eu_HID (s_ch) : where 'x' == collapsed and 'z' == unseen */
#ifndef TREE_VWINALL
if (q == Curwin) // note: the following is NOT indented
@ -5558,11 +5571,19 @@ static const char *task_show (const WIN_t *q, struct pids_stack *p) {
break;
/* s_int, scale_pcnt with special handling */
case EU_CPU:
{ float u = (float)rSv(EU_CPU, s_int) * Frame_etscale;
{ float u = (float)rSv(EU_CPU, s_int);
int n = rSv(EU_THD, s_int);
#ifndef TREE_VCPUOFF
// this eu_ADD is always zero, unless we're a collapsed parent
u += rSv(eu_ADD, u_int);
u *= Frame_etscale;
if (rSv(eu_HID, s_ch) != 'x' && u > 100.0 * n) u = 100.0 * n;
#else
u *= Frame_etscale;
/* process can't use more %cpu than number of threads it has
( thanks Jaromir Capik <jcapik@redhat.com> ) */
if (u > 100.0 * n) u = 100.0 * n;
#endif
if (u > Cpu_pmax) u = Cpu_pmax;
cp = scale_pcnt(u, W, Jn);
}

1
top/top.h
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@ -48,6 +48,7 @@
//#define TERMIOS_ONLY /* just limp along with native input only */
//#define TREE_NORESET /* sort keys do NOT force forest view OFF */
//#define TREE_SCANALL /* rescan array w/ forest view, avoid sort */
//#define TREE_VCPUOFF /* a collapsed parent excludes child's cpu */
//#define TREE_VPROMPT /* pid collapse/expand prompt, vs. top row */
//#define TREE_VWINALL /* pid collapse/expand impacts all windows */
//#define USE_X_COLHDR /* emphasize header vs. whole col, for 'x' */