From ec21588be108d092804eb72edbba2ba214bc6190 Mon Sep 17 00:00:00 2001 From: Jim Warner Date: Tue, 8 Sep 2020 00:00:00 -0500 Subject: [PATCH] library: tweak those system cpu statistics, api 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 --- proc/stat.c | 75 ++++++++++++++++++++++++++--------------------------- proc/stat.h | 14 +++++----- 2 files changed, 44 insertions(+), 45 deletions(-) diff --git a/proc/stat.c b/proc/stat.c index ff138adc..5efcc03e 100644 --- a/proc/stat.c +++ b/proc/stat.c @@ -67,7 +67,7 @@ struct stat_jifs { 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 { @@ -192,17 +192,17 @@ TICsetH(TIC_DELTA_STOLEN, sl_int, stolen) TICsetH(TIC_DELTA_GUEST, sl_int, guest) 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_BUSY, ull_int, xbsy) 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_BUSY, sl_int, xbsy) 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_INTERRUPTS, ul_int, intr) @@ -329,17 +329,17 @@ static struct { { RS(TIC_DELTA_GUEST), 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_BUSY), 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_BUSY), 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_INTERRUPTS), QS(ul_int), TS(ul_int) }, @@ -392,34 +392,33 @@ static inline void stat_assign_results ( static inline void stat_derive_unique ( struct hist_tic *this) { - /* note: we exclude guest tics from xtot since ... - 'user' already includes 'guest' - 'nice' already includes 'gnice' - ( see: ./kernel/sched/cputime.c, account_guest_time ) */ - this->new.xtot + /* note: we calculate these derived values in a manner consistent with + the calculations for cgroup accounting, as nearly as possible + ( see linux sources: ./kernel/cgroup/rstat.c, root_cgroup_cputime ) */ + this->new.xusr = this->new.user - + this->new.nice - + this->new.system - + this->new.idle - + this->new.iowait + + this->new.nice; + this->new.xsys + = this->new.system + this->new.irq - + this->new.sirq - + this->new.stolen; - this->new.xusr = this->new.user + this->new.nice; - /* this stolen guy is one i'm not sure of yet, but it's documented as: - "the time spent in other operating systems - when running in a virtualized environment" - so it would seem to apply to an 'involuntary wait' for a guest OS */ - this->new.xidl = this->new.idle + this->new.iowait + this->new.stolen; - this->new.xbsy = this->new.xtot - this->new.xidl; - this->new.xsys = this->new.xbsy - this->new.xusr; + + this->new.sirq; + this->new.xidl + = this->new.idle + + this->new.iowait; + this->new.xtot + = this->new.xusr + this->new.xsys + this->new.xidl + + this->new.stolen + + this->new.guest + + this->new.gnice; + this->new.xbsy + = this->new.xtot - this->new.xidl; // don't distort deltas when cpus are taken offline or brought online - if (this->new.xtot < this->old.xtot - || (this->new.xusr < this->old.xusr) + if (this->new.xusr < this->old.xusr + || (this->new.xsys < this->old.xsys) || (this->new.xidl < this->old.xidl) || (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)); } // 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.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.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; nod_ptr->count++; ; diff --git a/proc/stat.h b/proc/stat.h index d4c75534..9d0f3034 100644 --- a/proc/stat.h +++ b/proc/stat.h @@ -54,17 +54,17 @@ enum stat_item { STAT_TIC_DELTA_GUEST, // 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_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_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_IDLE, // sl_int " - STAT_TIC_SUM_DELTA_USER, // sl_int " - STAT_TIC_SUM_DELTA_BUSY, // sl_int " + STAT_TIC_SUM_DELTA_USER, // sl_int derived from above 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_INTERRUPTS, // ul_int "