Date: Fri, 19 Dec 2025 09:19:16 +0000 From: Olivier Certner <olce@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org Cc: Mark Johnston <markj@FreeBSD.org> Subject: git: fd404e957dd9 - stable/14 - racct: Fix accounting of CPU time for the system idle process Message-ID: <69451894.3f880.c951a04@gitrepo.freebsd.org>
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The branch stable/14 has been updated by olce: URL: https://cgit.FreeBSD.org/src/commit/?id=fd404e957dd93d0e8525e4bc37df3f66610ca19d commit fd404e957dd93d0e8525e4bc37df3f66610ca19d Author: Mark Johnston <markj@FreeBSD.org> AuthorDate: 2025-05-01 13:59:55 +0000 Commit: Olivier Certner <olce@FreeBSD.org> CommitDate: 2025-12-19 09:16:46 +0000 racct: Fix accounting of CPU time for the system idle process - Add a flag which cleanly indicates that a given process is the system idle process. - Modify racctd() to skip over the idle proc when aggregating CPU time and other metrics which don't apply to the idle thread. - Remove handling for idle threads from racct_getpcpu(). PR: 269097 Reviewed by: olce, kib Sponsored by: Klara, Inc. Differential Revision: https://reviews.freebsd.org/D50073 (cherry picked from commit 33be1632047c05dbfcc139476e05f49c3a86d560) --- sys/kern/kern_idle.c | 3 +++ sys/kern/kern_racct.c | 22 ++++------------------ sys/sys/proc.h | 2 +- 3 files changed, 8 insertions(+), 19 deletions(-) diff --git a/sys/kern/kern_idle.c b/sys/kern/kern_idle.c index 0569659bdc73..0d0f496a1a03 100644 --- a/sys/kern/kern_idle.c +++ b/sys/kern/kern_idle.c @@ -83,4 +83,7 @@ idle_setup(void *dummy) #ifdef SMP } #endif + PROC_LOCK(p); + p->p_flag |= P_IDLEPROC; + PROC_UNLOCK(p); } diff --git a/sys/kern/kern_racct.c b/sys/kern/kern_racct.c index b121e24b9354..13df4724f860 100644 --- a/sys/kern/kern_racct.c +++ b/sys/kern/kern_racct.c @@ -322,15 +322,13 @@ racct_getpcpu(struct proc *p, u_int pcpu) u_int swtime; #ifdef SCHED_4BSD fixpt_t pctcpu, pctcpu_next; -#endif -#ifdef SMP - struct pcpu *pc; - int found; #endif fixpt_t p_pctcpu; struct thread *td; ASSERT_RACCT_ENABLED(); + KASSERT((p->p_flag & P_IDLEPROC) == 0, + ("racct_getpcpu: idle process %p", p)); /* * If the process is swapped out, we count its %cpu usage as zero. @@ -350,19 +348,6 @@ racct_getpcpu(struct proc *p, u_int pcpu) p_pctcpu = 0; FOREACH_THREAD_IN_PROC(p, td) { - if (td == PCPU_GET(idlethread)) - continue; -#ifdef SMP - found = 0; - STAILQ_FOREACH(pc, &cpuhead, pc_allcpu) { - if (td == pc->pc_idlethread) { - found = 1; - break; - } - } - if (found) - continue; -#endif thread_lock(td); #ifdef SCHED_4BSD pctcpu = sched_pctcpu(td); @@ -1258,7 +1243,8 @@ racctd(void) FOREACH_PROC_IN_SYSTEM(p) { PROC_LOCK(p); - if (p->p_state != PRS_NORMAL) { + if (p->p_state != PRS_NORMAL || + (p->p_flag & P_IDLEPROC) != 0) { if (p->p_state == PRS_ZOMBIE) racct_set(p, RACCT_PCTCPU, 0); PROC_UNLOCK(p); diff --git a/sys/sys/proc.h b/sys/sys/proc.h index a094af09a21a..06506f7d03ed 100644 --- a/sys/sys/proc.h +++ b/sys/sys/proc.h @@ -807,7 +807,7 @@ struct proc { lock. */ #define P_CONTROLT 0x00000002 /* Has a controlling terminal. */ #define P_KPROC 0x00000004 /* Kernel process. */ -#define P_UNUSED3 0x00000008 /* --available-- */ +#define P_IDLEPROC 0x00000008 /* Container for system idle threads. */ #define P_PPWAIT 0x00000010 /* Parent is waiting for child to exec/exit. */ #define P_PROFIL 0x00000020 /* Has started profiling. */help
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