Author: mjg Date: Wed Aug 28 16:18:23 2019 New Revision: 351572 URL: https://svnweb.freebsd.org/changeset/base/351572
Log: proc: eliminate the zombproc list It is not needed by anything in the kernel and it slightly drives up contention on both proctree and allproc locks. Reviewed by: kib Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D21447 Modified: head/sys/ddb/db_ps.c head/sys/ddb/db_thread.c head/sys/kern/kern_exit.c head/sys/kern/kern_proc.c head/sys/kern/kern_racct.c head/sys/sys/proc.h Modified: head/sys/ddb/db_ps.c ============================================================================== --- head/sys/ddb/db_ps.c Wed Aug 28 16:16:35 2019 (r351571) +++ head/sys/ddb/db_ps.c Wed Aug 28 16:18:23 2019 (r351572) @@ -54,6 +54,7 @@ __FBSDID("$FreeBSD$"); static void dumpthread(volatile struct proc *p, volatile struct thread *td, int all); +static void db_ps_proc(struct proc *p); static int ps_mode; /* @@ -105,146 +106,157 @@ dump_args(volatile struct proc *p) void db_ps(db_expr_t addr, bool hasaddr, db_expr_t count, char *modif) { - volatile struct proc *p, *pp; - volatile struct thread *td; - struct ucred *cred; - struct pgrp *pgrp; - char state[9]; - int np, rflag, sflag, dflag, lflag, wflag; + struct proc *p; + int i, j; ps_mode = modif[0] == 'a' ? PRINT_ARGS : PRINT_NONE; - np = nprocs; - if (!LIST_EMPTY(&allproc)) - p = LIST_FIRST(&allproc); - else - p = &proc0; - #ifdef __LP64__ db_printf(" pid ppid pgrp uid state wmesg wchan cmd\n"); #else db_printf(" pid ppid pgrp uid state wmesg wchan cmd\n"); #endif - while (--np >= 0 && !db_pager_quit) { - if (p == NULL) { - db_printf("oops, ran out of processes early!\n"); - break; + + if (!LIST_EMPTY(&allproc)) + p = LIST_FIRST(&allproc); + else + p = &proc0; + for (; p != NULL && !db_pager_quit; p = LIST_NEXT(p, p_list)) + db_ps_proc(p); + + /* + * Do zombies. + */ + for (i = 0; i < pidhashlock + 1 && !db_pager_quit; i++) { + for (j = i; j <= pidhash && !db_pager_quit; j += pidhashlock + 1) { + LIST_FOREACH(p, &pidhashtbl[j], p_hash) { + if (p->p_state == PRS_ZOMBIE) + db_ps_proc(p); + } } - pp = p->p_pptr; - if (pp == NULL) - pp = p; + } +} - cred = p->p_ucred; - pgrp = p->p_pgrp; - db_printf("%5d %5d %5d %5d ", p->p_pid, pp->p_pid, - pgrp != NULL ? pgrp->pg_id : 0, - cred != NULL ? cred->cr_ruid : 0); +static void +db_ps_proc(struct proc *p) +{ + volatile struct proc *pp; + volatile struct thread *td; + struct ucred *cred; + struct pgrp *pgrp; + char state[9]; + int rflag, sflag, dflag, lflag, wflag; - /* Determine our primary process state. */ - switch (p->p_state) { - case PRS_NORMAL: - if (P_SHOULDSTOP(p)) - state[0] = 'T'; - else { - /* - * One of D, L, R, S, W. For a - * multithreaded process we will use - * the state of the thread with the - * highest precedence. The - * precendence order from high to low - * is R, L, D, S, W. If no thread is - * in a sane state we use '?' for our - * primary state. - */ - rflag = sflag = dflag = lflag = wflag = 0; - FOREACH_THREAD_IN_PROC(p, td) { - if (td->td_state == TDS_RUNNING || - td->td_state == TDS_RUNQ || - td->td_state == TDS_CAN_RUN) - rflag++; - if (TD_ON_LOCK(td)) - lflag++; - if (TD_IS_SLEEPING(td)) { - if (!(td->td_flags & TDF_SINTR)) - dflag++; - else - sflag++; - } - if (TD_AWAITING_INTR(td)) - wflag++; + pp = p->p_pptr; + if (pp == NULL) + pp = p; + + cred = p->p_ucred; + pgrp = p->p_pgrp; + db_printf("%5d %5d %5d %5d ", p->p_pid, pp->p_pid, + pgrp != NULL ? pgrp->pg_id : 0, + cred != NULL ? cred->cr_ruid : 0); + + /* Determine our primary process state. */ + switch (p->p_state) { + case PRS_NORMAL: + if (P_SHOULDSTOP(p)) + state[0] = 'T'; + else { + /* + * One of D, L, R, S, W. For a + * multithreaded process we will use + * the state of the thread with the + * highest precedence. The + * precendence order from high to low + * is R, L, D, S, W. If no thread is + * in a sane state we use '?' for our + * primary state. + */ + rflag = sflag = dflag = lflag = wflag = 0; + FOREACH_THREAD_IN_PROC(p, td) { + if (td->td_state == TDS_RUNNING || + td->td_state == TDS_RUNQ || + td->td_state == TDS_CAN_RUN) + rflag++; + if (TD_ON_LOCK(td)) + lflag++; + if (TD_IS_SLEEPING(td)) { + if (!(td->td_flags & TDF_SINTR)) + dflag++; + else + sflag++; } - if (rflag) - state[0] = 'R'; - else if (lflag) - state[0] = 'L'; - else if (dflag) - state[0] = 'D'; - else if (sflag) - state[0] = 'S'; - else if (wflag) - state[0] = 'W'; - else - state[0] = '?'; + if (TD_AWAITING_INTR(td)) + wflag++; } - break; - case PRS_NEW: - state[0] = 'N'; - break; - case PRS_ZOMBIE: - state[0] = 'Z'; - break; - default: - state[0] = 'U'; - break; + if (rflag) + state[0] = 'R'; + else if (lflag) + state[0] = 'L'; + else if (dflag) + state[0] = 'D'; + else if (sflag) + state[0] = 'S'; + else if (wflag) + state[0] = 'W'; + else + state[0] = '?'; } - state[1] = '\0'; + break; + case PRS_NEW: + state[0] = 'N'; + break; + case PRS_ZOMBIE: + state[0] = 'Z'; + break; + default: + state[0] = 'U'; + break; + } + state[1] = '\0'; - /* Additional process state flags. */ - if (!(p->p_flag & P_INMEM)) - strlcat(state, "W", sizeof(state)); - if (p->p_flag & P_TRACED) - strlcat(state, "X", sizeof(state)); - if (p->p_flag & P_WEXIT && p->p_state != PRS_ZOMBIE) - strlcat(state, "E", sizeof(state)); - if (p->p_flag & P_PPWAIT) - strlcat(state, "V", sizeof(state)); - if (p->p_flag & P_SYSTEM || p->p_lock > 0) - strlcat(state, "L", sizeof(state)); - if (p->p_pgrp != NULL && p->p_session != NULL && - SESS_LEADER(p)) - strlcat(state, "s", sizeof(state)); - /* Cheated here and didn't compare pgid's. */ - if (p->p_flag & P_CONTROLT) - strlcat(state, "+", sizeof(state)); - if (cred != NULL && jailed(cred)) - strlcat(state, "J", sizeof(state)); - db_printf(" %-6.6s ", state); - if (p->p_flag & P_HADTHREADS) { + /* Additional process state flags. */ + if (!(p->p_flag & P_INMEM)) + strlcat(state, "W", sizeof(state)); + if (p->p_flag & P_TRACED) + strlcat(state, "X", sizeof(state)); + if (p->p_flag & P_WEXIT && p->p_state != PRS_ZOMBIE) + strlcat(state, "E", sizeof(state)); + if (p->p_flag & P_PPWAIT) + strlcat(state, "V", sizeof(state)); + if (p->p_flag & P_SYSTEM || p->p_lock > 0) + strlcat(state, "L", sizeof(state)); + if (p->p_pgrp != NULL && p->p_session != NULL && + SESS_LEADER(p)) + strlcat(state, "s", sizeof(state)); + /* Cheated here and didn't compare pgid's. */ + if (p->p_flag & P_CONTROLT) + strlcat(state, "+", sizeof(state)); + if (cred != NULL && jailed(cred)) + strlcat(state, "J", sizeof(state)); + db_printf(" %-6.6s ", state); + if (p->p_flag & P_HADTHREADS) { #ifdef __LP64__ - db_printf(" (threaded) "); + db_printf(" (threaded) "); #else - db_printf(" (threaded) "); + db_printf(" (threaded) "); #endif - if (p->p_flag & P_SYSTEM) - db_printf("["); - db_printf("%s", p->p_comm); - if (p->p_flag & P_SYSTEM) - db_printf("]"); - if (ps_mode == PRINT_ARGS) { - db_printf(" "); - dump_args(p); - } - db_printf("\n"); + if (p->p_flag & P_SYSTEM) + db_printf("["); + db_printf("%s", p->p_comm); + if (p->p_flag & P_SYSTEM) + db_printf("]"); + if (ps_mode == PRINT_ARGS) { + db_printf(" "); + dump_args(p); } - FOREACH_THREAD_IN_PROC(p, td) { - dumpthread(p, td, p->p_flag & P_HADTHREADS); - if (db_pager_quit) - break; - } - - p = LIST_NEXT(p, p_list); - if (p == NULL && np > 0) - p = LIST_FIRST(&zombproc); + db_printf("\n"); + } + FOREACH_THREAD_IN_PROC(p, td) { + dumpthread(p, td, p->p_flag & P_HADTHREADS); + if (db_pager_quit) + break; } } Modified: head/sys/ddb/db_thread.c ============================================================================== --- head/sys/ddb/db_thread.c Wed Aug 28 16:16:35 2019 (r351571) +++ head/sys/ddb/db_thread.c Wed Aug 28 16:18:23 2019 (r351572) @@ -125,14 +125,10 @@ db_lookup_thread(db_expr_t addr, bool check_pid) if (td != NULL) return (td); if (check_pid) { - FOREACH_PROC_IN_SYSTEM(p) { + LIST_FOREACH(p, PIDHASH(decaddr), p_hash) { if (p->p_pid == decaddr) return (FIRST_THREAD_IN_PROC(p)); } - LIST_FOREACH(p, &zombproc, p_list) { - if (p->p_pid == decaddr) - return (FIRST_THREAD_IN_PROC(p)); - } } return ((struct thread *)addr); } @@ -151,11 +147,7 @@ db_lookup_proc(db_expr_t addr) decaddr = db_hex2dec(addr); if (decaddr != -1) { - FOREACH_PROC_IN_SYSTEM(p) { - if (p->p_pid == decaddr) - return (p); - } - LIST_FOREACH(p, &zombproc, p_list) { + LIST_FOREACH(p, PIDHASH(decaddr), p_hash) { if (p->p_pid == decaddr) return (p); } Modified: head/sys/kern/kern_exit.c ============================================================================== --- head/sys/kern/kern_exit.c Wed Aug 28 16:16:35 2019 (r351571) +++ head/sys/kern/kern_exit.c Wed Aug 28 16:18:23 2019 (r351572) @@ -447,13 +447,10 @@ exit1(struct thread *td, int rval, int signo) WITNESS_WARN(WARN_PANIC, NULL, "process (pid %d) exiting", p->p_pid); /* - * Move proc from allproc queue to zombproc. + * Remove from allproc. It still sits in the hash. */ sx_xlock(&allproc_lock); - sx_xlock(&zombproc_lock); LIST_REMOVE(p, p_list); - LIST_INSERT_HEAD(&zombproc, p, p_list); - sx_xunlock(&zombproc_lock); sx_xunlock(&allproc_lock); sx_xlock(&proctree_lock); @@ -903,9 +900,6 @@ proc_reap(struct thread *td, struct proc *p, int *stat * Remove other references to this process to ensure we have an * exclusive reference. */ - sx_xlock(&zombproc_lock); - LIST_REMOVE(p, p_list); /* off zombproc */ - sx_xunlock(&zombproc_lock); sx_xlock(PIDHASHLOCK(p->p_pid)); LIST_REMOVE(p, p_hash); sx_xunlock(PIDHASHLOCK(p->p_pid)); Modified: head/sys/kern/kern_proc.c ============================================================================== --- head/sys/kern/kern_proc.c Wed Aug 28 16:16:35 2019 (r351571) +++ head/sys/kern/kern_proc.c Wed Aug 28 16:18:23 2019 (r351572) @@ -124,9 +124,7 @@ u_long pidhashlock; struct pgrphashhead *pgrphashtbl; u_long pgrphash; struct proclist allproc; -struct proclist zombproc; struct sx __exclusive_cache_line allproc_lock; -struct sx __exclusive_cache_line zombproc_lock; struct sx __exclusive_cache_line proctree_lock; struct mtx __exclusive_cache_line ppeers_lock; struct mtx __exclusive_cache_line procid_lock; @@ -177,12 +175,10 @@ procinit(void) u_long i; sx_init(&allproc_lock, "allproc"); - sx_init(&zombproc_lock, "zombproc"); sx_init(&proctree_lock, "proctree"); mtx_init(&ppeers_lock, "p_peers", NULL, MTX_DEF); mtx_init(&procid_lock, "procid", NULL, MTX_DEF); LIST_INIT(&allproc); - LIST_INIT(&zombproc); pidhashtbl = hashinit(maxproc / 4, M_PROC, &pidhash); pidhashlock = (pidhash + 1) / 64; if (pidhashlock > 0) Modified: head/sys/kern/kern_racct.c ============================================================================== --- head/sys/kern/kern_racct.c Wed Aug 28 16:16:35 2019 (r351571) +++ head/sys/kern/kern_racct.c Wed Aug 28 16:18:23 2019 (r351572) @@ -1256,17 +1256,11 @@ racctd(void) sx_slock(&allproc_lock); - sx_slock(&zombproc_lock); - LIST_FOREACH(p, &zombproc, p_list) { - PROC_LOCK(p); - racct_set(p, RACCT_PCTCPU, 0); - PROC_UNLOCK(p); - } - sx_sunlock(&zombproc_lock); - FOREACH_PROC_IN_SYSTEM(p) { PROC_LOCK(p); if (p->p_state != PRS_NORMAL) { + if (p->p_state == PRS_ZOMBIE) + racct_set(p, RACCT_PCTCPU, 0); PROC_UNLOCK(p); continue; } Modified: head/sys/sys/proc.h ============================================================================== --- head/sys/sys/proc.h Wed Aug 28 16:16:35 2019 (r351571) +++ head/sys/sys/proc.h Wed Aug 28 16:18:23 2019 (r351572) @@ -967,7 +967,6 @@ extern u_long pgrphash; extern struct sx allproc_lock; extern int allproc_gen; -extern struct sx zombproc_lock; extern struct sx proctree_lock; extern struct mtx ppeers_lock; extern struct mtx procid_lock; @@ -985,7 +984,6 @@ LIST_HEAD(proclist, proc); TAILQ_HEAD(procqueue, proc); TAILQ_HEAD(threadqueue, thread); extern struct proclist allproc; /* List of all processes. */ -extern struct proclist zombproc; /* List of zombie processes. */ extern struct proc *initproc, *pageproc; /* Process slots for init, pager. */ extern struct uma_zone *proc_zone; _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
