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library: tweak those system cpu statistics, <stat> api

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This patch may be a little misleading in terms of size
since most of the changes just reorder a little logic.
The most significant changes involve two GUEST values.

My original implementation excluded such tics from the
TOTAL calculation and, therefore, the BUSY figure too.

That decision was erroneously based on some code found
in ./kernel/sched/cputime.c which in hindsight applies
only to processes, not those system level cpu figures.

[ another likely oops classified STOLEN tics as IDLE ]

So, this patch attempts to bring those SUM values into
better agreement with the calculations performed for a
root cgroup (see ./kernel/cgroup/rstat.c source file).

[ we differ from those above in that we also include ]
[ the IDLE plus IOWAIT tics in our TOTAL calculation ]

Signed-off-by: Jim Warner <james.warner@comcast.net>
This commit is contained in:
Jim Warner 2020-09-08 00:00:00 -05:00 committed by Craig Small
parent bc55757231
commit ec21588be1
2 changed files with 44 additions and 45 deletions
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75
proc/stat.c
View File

@ -67,7 +67,7 @@
struct stat_jifs { struct stat_jifs {
unsigned long long user, nice, system, idle, iowait, irq, sirq, stolen, guest, gnice; unsigned long long user, nice, system, idle, iowait, irq, sirq, stolen, guest, gnice;
unsigned long long xtot, xbsy, xidl, xusr, xsys; unsigned long long xusr, xsys, xidl, xbsy, xtot;
}; };
struct stat_data { struct stat_data {
@ -192,17 +192,17 @@ TICsetH(TIC_DELTA_STOLEN, sl_int, stolen)
TICsetH(TIC_DELTA_GUEST, sl_int, guest) TICsetH(TIC_DELTA_GUEST, sl_int, guest)
TICsetH(TIC_DELTA_GUEST_NICE, sl_int, gnice) TICsetH(TIC_DELTA_GUEST_NICE, sl_int, gnice)
TIC_set(TIC_SUM_TOTAL, ull_int, xtot)
TIC_set(TIC_SUM_IDLE, ull_int, xidl)
TIC_set(TIC_SUM_USER, ull_int, xusr) TIC_set(TIC_SUM_USER, ull_int, xusr)
TIC_set(TIC_SUM_BUSY, ull_int, xbsy)
TIC_set(TIC_SUM_SYSTEM, ull_int, xsys) TIC_set(TIC_SUM_SYSTEM, ull_int, xsys)
TIC_set(TIC_SUM_IDLE, ull_int, xidl)
TIC_set(TIC_SUM_BUSY, ull_int, xbsy)
TIC_set(TIC_SUM_TOTAL, ull_int, xtot)
TICsetH(TIC_SUM_DELTA_TOTAL, sl_int, xtot)
TICsetH(TIC_SUM_DELTA_IDLE, sl_int, xidl)
TICsetH(TIC_SUM_DELTA_USER, sl_int, xusr) TICsetH(TIC_SUM_DELTA_USER, sl_int, xusr)
TICsetH(TIC_SUM_DELTA_BUSY, sl_int, xbsy)
TICsetH(TIC_SUM_DELTA_SYSTEM, sl_int, xsys) TICsetH(TIC_SUM_DELTA_SYSTEM, sl_int, xsys)
TICsetH(TIC_SUM_DELTA_IDLE, sl_int, xidl)
TICsetH(TIC_SUM_DELTA_BUSY, sl_int, xbsy)
TICsetH(TIC_SUM_DELTA_TOTAL, sl_int, xtot)
SYS_set(SYS_CTX_SWITCHES, ul_int, ctxt) SYS_set(SYS_CTX_SWITCHES, ul_int, ctxt)
SYS_set(SYS_INTERRUPTS, ul_int, intr) SYS_set(SYS_INTERRUPTS, ul_int, intr)
@ -329,17 +329,17 @@ static struct {
{ RS(TIC_DELTA_GUEST), QS(sl_int), TS(sl_int) }, { RS(TIC_DELTA_GUEST), QS(sl_int), TS(sl_int) },
{ RS(TIC_DELTA_GUEST_NICE), QS(sl_int), TS(sl_int) }, { RS(TIC_DELTA_GUEST_NICE), QS(sl_int), TS(sl_int) },
{ RS(TIC_SUM_TOTAL), QS(ull_int), TS(ull_int) },
{ RS(TIC_SUM_IDLE), QS(ull_int), TS(ull_int) },
{ RS(TIC_SUM_USER), QS(ull_int), TS(ull_int) }, { RS(TIC_SUM_USER), QS(ull_int), TS(ull_int) },
{ RS(TIC_SUM_BUSY), QS(ull_int), TS(ull_int) },
{ RS(TIC_SUM_SYSTEM), QS(ull_int), TS(ull_int) }, { RS(TIC_SUM_SYSTEM), QS(ull_int), TS(ull_int) },
{ RS(TIC_SUM_IDLE), QS(ull_int), TS(ull_int) },
{ RS(TIC_SUM_BUSY), QS(ull_int), TS(ull_int) },
{ RS(TIC_SUM_TOTAL), QS(ull_int), TS(ull_int) },
{ RS(TIC_SUM_DELTA_TOTAL), QS(sl_int), TS(sl_int) },
{ RS(TIC_SUM_DELTA_IDLE), QS(sl_int), TS(sl_int) },
{ RS(TIC_SUM_DELTA_USER), QS(sl_int), TS(sl_int) }, { RS(TIC_SUM_DELTA_USER), QS(sl_int), TS(sl_int) },
{ RS(TIC_SUM_DELTA_BUSY), QS(sl_int), TS(sl_int) },
{ RS(TIC_SUM_DELTA_SYSTEM), QS(sl_int), TS(sl_int) }, { RS(TIC_SUM_DELTA_SYSTEM), QS(sl_int), TS(sl_int) },
{ RS(TIC_SUM_DELTA_IDLE), QS(sl_int), TS(sl_int) },
{ RS(TIC_SUM_DELTA_BUSY), QS(sl_int), TS(sl_int) },
{ RS(TIC_SUM_DELTA_TOTAL), QS(sl_int), TS(sl_int) },
{ RS(SYS_CTX_SWITCHES), QS(ul_int), TS(ul_int) }, { RS(SYS_CTX_SWITCHES), QS(ul_int), TS(ul_int) },
{ RS(SYS_INTERRUPTS), QS(ul_int), TS(ul_int) }, { RS(SYS_INTERRUPTS), QS(ul_int), TS(ul_int) },
@ -392,34 +392,33 @@ static inline void stat_assign_results (
static inline void stat_derive_unique ( static inline void stat_derive_unique (
struct hist_tic *this) struct hist_tic *this)
{ {
/* note: we exclude guest tics from xtot since ... /* note: we calculate these derived values in a manner consistent with
'user' already includes 'guest' the calculations for cgroup accounting, as nearly as possible
'nice' already includes 'gnice' ( see linux sources: ./kernel/cgroup/rstat.c, root_cgroup_cputime ) */
( see: ./kernel/sched/cputime.c, account_guest_time ) */ this->new.xusr
this->new.xtot
= this->new.user = this->new.user
+ this->new.nice + this->new.nice;
+ this->new.system this->new.xsys
+ this->new.idle = this->new.system
+ this->new.iowait
+ this->new.irq + this->new.irq
+ this->new.sirq + this->new.sirq;
+ this->new.stolen; this->new.xidl
this->new.xusr = this->new.user + this->new.nice; = this->new.idle
/* this stolen guy is one i'm not sure of yet, but it's documented as: + this->new.iowait;
"the time spent in other operating systems this->new.xtot
when running in a virtualized environment" = this->new.xusr + this->new.xsys + this->new.xidl
so it would seem to apply to an 'involuntary wait' for a guest OS */ + this->new.stolen
this->new.xidl = this->new.idle + this->new.iowait + this->new.stolen; + this->new.guest
this->new.xbsy = this->new.xtot - this->new.xidl; + this->new.gnice;
this->new.xsys = this->new.xbsy - this->new.xusr; this->new.xbsy
= this->new.xtot - this->new.xidl;
// don't distort deltas when cpus are taken offline or brought online // don't distort deltas when cpus are taken offline or brought online
if (this->new.xtot < this->old.xtot if (this->new.xusr < this->old.xusr
|| (this->new.xusr < this->old.xusr) || (this->new.xsys < this->old.xsys)
|| (this->new.xidl < this->old.xidl) || (this->new.xidl < this->old.xidl)
|| (this->new.xbsy < this->old.xbsy) || (this->new.xbsy < this->old.xbsy)
|| (this->new.xsys < this->old.xsys)) || (this->new.xtot < this->old.xtot))
memcpy(&this->old, &this->new, sizeof(struct stat_jifs)); memcpy(&this->old, &this->new, sizeof(struct stat_jifs));
} // end: stat_derive_unique } // end: stat_derive_unique
@ -526,11 +525,11 @@ static int stat_make_numa_hist (
nod_ptr->new.guest += cpu_ptr->new.guest; nod_ptr->old.guest += cpu_ptr->old.guest; nod_ptr->new.guest += cpu_ptr->new.guest; nod_ptr->old.guest += cpu_ptr->old.guest;
nod_ptr->new.gnice += cpu_ptr->new.gnice; nod_ptr->old.gnice += cpu_ptr->old.gnice; nod_ptr->new.gnice += cpu_ptr->new.gnice; nod_ptr->old.gnice += cpu_ptr->old.gnice;
nod_ptr->new.xtot += cpu_ptr->new.xtot; nod_ptr->old.xtot += cpu_ptr->old.xtot;
nod_ptr->new.xbsy += cpu_ptr->new.xbsy; nod_ptr->old.xbsy += cpu_ptr->old.xbsy;
nod_ptr->new.xidl += cpu_ptr->new.xidl; nod_ptr->old.xidl += cpu_ptr->old.xidl;
nod_ptr->new.xusr += cpu_ptr->new.xusr; nod_ptr->old.xusr += cpu_ptr->old.xusr; nod_ptr->new.xusr += cpu_ptr->new.xusr; nod_ptr->old.xusr += cpu_ptr->old.xusr;
nod_ptr->new.xsys += cpu_ptr->new.xsys; nod_ptr->old.xsys += cpu_ptr->old.xsys; nod_ptr->new.xsys += cpu_ptr->new.xsys; nod_ptr->old.xsys += cpu_ptr->old.xsys;
nod_ptr->new.xidl += cpu_ptr->new.xidl; nod_ptr->old.xidl += cpu_ptr->old.xidl;
nod_ptr->new.xbsy += cpu_ptr->new.xbsy; nod_ptr->old.xbsy += cpu_ptr->old.xbsy;
nod_ptr->new.xtot += cpu_ptr->new.xtot; nod_ptr->old.xtot += cpu_ptr->old.xtot;
cpu_ptr->numa_node = nod_ptr->numa_node = node; cpu_ptr->numa_node = nod_ptr->numa_node = node;
nod_ptr->count++; ; nod_ptr->count++; ;

14
proc/stat.h
View File

@ -54,17 +54,17 @@ enum stat_item {
STAT_TIC_DELTA_GUEST, // sl_int " STAT_TIC_DELTA_GUEST, // sl_int "
STAT_TIC_DELTA_GUEST_NICE, // sl_int " STAT_TIC_DELTA_GUEST_NICE, // sl_int "
STAT_TIC_SUM_TOTAL, // ull_int derived from all except GUEST tics
STAT_TIC_SUM_IDLE, // ull_int derived from IDLE + IOWAIT + STOLEN tics
STAT_TIC_SUM_USER, // ull_int derived from USER + NICE tics STAT_TIC_SUM_USER, // ull_int derived from USER + NICE tics
STAT_TIC_SUM_SYSTEM, // ull_int derived from SYSTEM + IRQ + SOFTIRQ tics
STAT_TIC_SUM_IDLE, // ull_int derived from IDLE + IOWAIT tics
STAT_TIC_SUM_BUSY, // ull_int derived from SUM_TOTAL - SUM_IDLE tics STAT_TIC_SUM_BUSY, // ull_int derived from SUM_TOTAL - SUM_IDLE tics
STAT_TIC_SUM_SYSTEM, // ull_int derived from SUM_BUSY - SUM_USER tics STAT_TIC_SUM_TOTAL, // ull_int derived from sum of all 10 tics
STAT_TIC_SUM_DELTA_TOTAL, // sl_int derived from above STAT_TIC_SUM_DELTA_USER, // sl_int derived from above
STAT_TIC_SUM_DELTA_IDLE, // sl_int "
STAT_TIC_SUM_DELTA_USER, // sl_int "
STAT_TIC_SUM_DELTA_BUSY, // sl_int "
STAT_TIC_SUM_DELTA_SYSTEM, // sl_int " STAT_TIC_SUM_DELTA_SYSTEM, // sl_int "
STAT_TIC_SUM_DELTA_IDLE, // sl_int "
STAT_TIC_SUM_DELTA_BUSY, // sl_int "
STAT_TIC_SUM_DELTA_TOTAL, // sl_int "
STAT_SYS_CTX_SWITCHES, // ul_int /proc/stat STAT_SYS_CTX_SWITCHES, // ul_int /proc/stat
STAT_SYS_INTERRUPTS, // ul_int " STAT_SYS_INTERRUPTS, // ul_int "