From owner-svn-src-head@freebsd.org Wed Dec 19 20:27:28 2018 Return-Path: Delivered-To: svn-src-head@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 14E2A1343161; Wed, 19 Dec 2018 20:27:28 +0000 (UTC) (envelope-from mjg@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) server-signature RSA-PSS (4096 bits) client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id A29DA6BF2C; Wed, 19 Dec 2018 20:27:27 +0000 (UTC) (envelope-from mjg@FreeBSD.org) Received: from repo.freebsd.org (repo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 7BC881AF95; Wed, 19 Dec 2018 20:27:27 +0000 (UTC) (envelope-from mjg@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id wBJKRRpr074404; Wed, 19 Dec 2018 20:27:27 GMT (envelope-from mjg@FreeBSD.org) Received: (from mjg@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id wBJKRQZY074401; Wed, 19 Dec 2018 20:27:26 GMT (envelope-from mjg@FreeBSD.org) Message-Id: <201812192027.wBJKRQZY074401@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: mjg set sender to mjg@FreeBSD.org using -f From: Mateusz Guzik Date: Wed, 19 Dec 2018 20:27:26 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r342236 - in head/sys: kern sys X-SVN-Group: head X-SVN-Commit-Author: mjg X-SVN-Commit-Paths: in head/sys: kern sys X-SVN-Commit-Revision: 342236 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: A29DA6BF2C X-Spamd-Bar: -- Authentication-Results: mx1.freebsd.org X-Spamd-Result: default: False [-2.96 / 15.00]; local_wl_from(0.00)[FreeBSD.org]; NEURAL_HAM_MEDIUM(-1.00)[-0.999,0]; NEURAL_HAM_LONG(-1.00)[-0.998,0]; NEURAL_HAM_SHORT(-0.96)[-0.961,0]; ASN(0.00)[asn:11403, ipnet:2610:1c1:1::/48, country:US] X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 19 Dec 2018 20:27:28 -0000 Author: mjg Date: Wed Dec 19 20:27:26 2018 New Revision: 342236 URL: https://svnweb.freebsd.org/changeset/base/342236 Log: Deinline vfork handling out of the syscall return path. vfork is rarely called (comparatively to other syscalls) and it avoidably pollutes the fast path. Sponsored by: The FreeBSD Foundation Modified: head/sys/kern/kern_fork.c head/sys/kern/subr_syscall.c head/sys/sys/proc.h Modified: head/sys/kern/kern_fork.c ============================================================================== --- head/sys/kern/kern_fork.c Wed Dec 19 20:25:58 2018 (r342235) +++ head/sys/kern/kern_fork.c Wed Dec 19 20:27:26 2018 (r342236) @@ -757,6 +757,51 @@ do_fork(struct thread *td, struct fork_req *fr, struct } } +void +fork_rfppwait(struct thread *td) +{ + struct proc *p, *p2; + + MPASS(td->td_pflags & TDP_RFPPWAIT); + + p = td->td_proc; + /* + * Preserve synchronization semantics of vfork. If + * waiting for child to exec or exit, fork set + * P_PPWAIT on child, and there we sleep on our proc + * (in case of exit). + * + * Do it after the ptracestop() above is finished, to + * not block our debugger until child execs or exits + * to finish vfork wait. + */ + td->td_pflags &= ~TDP_RFPPWAIT; + p2 = td->td_rfppwait_p; +again: + PROC_LOCK(p2); + while (p2->p_flag & P_PPWAIT) { + PROC_LOCK(p); + if (thread_suspend_check_needed()) { + PROC_UNLOCK(p2); + thread_suspend_check(0); + PROC_UNLOCK(p); + goto again; + } else { + PROC_UNLOCK(p); + } + cv_timedwait(&p2->p_pwait, &p2->p_mtx, hz); + } + PROC_UNLOCK(p2); + + if (td->td_dbgflags & TDB_VFORK) { + PROC_LOCK(p); + if (p->p_ptevents & PTRACE_VFORK) + ptracestop(td, SIGTRAP, NULL); + td->td_dbgflags &= ~TDB_VFORK; + PROC_UNLOCK(p); + } +} + int fork1(struct thread *td, struct fork_req *fr) { Modified: head/sys/kern/subr_syscall.c ============================================================================== --- head/sys/kern/subr_syscall.c Wed Dec 19 20:25:58 2018 (r342235) +++ head/sys/kern/subr_syscall.c Wed Dec 19 20:27:26 2018 (r342236) @@ -165,7 +165,7 @@ syscallenter(struct thread *td) static inline void syscallret(struct thread *td, int error) { - struct proc *p, *p2; + struct proc *p; struct syscall_args *sa; ksiginfo_t ksi; int traced, error1; @@ -230,41 +230,6 @@ syscallret(struct thread *td, int error) PROC_UNLOCK(p); } - if (__predict_false(td->td_pflags & TDP_RFPPWAIT)) { - /* - * Preserve synchronization semantics of vfork. If - * waiting for child to exec or exit, fork set - * P_PPWAIT on child, and there we sleep on our proc - * (in case of exit). - * - * Do it after the ptracestop() above is finished, to - * not block our debugger until child execs or exits - * to finish vfork wait. - */ - td->td_pflags &= ~TDP_RFPPWAIT; - p2 = td->td_rfppwait_p; -again: - PROC_LOCK(p2); - while (p2->p_flag & P_PPWAIT) { - PROC_LOCK(p); - if (thread_suspend_check_needed()) { - PROC_UNLOCK(p2); - thread_suspend_check(0); - PROC_UNLOCK(p); - goto again; - } else { - PROC_UNLOCK(p); - } - cv_timedwait(&p2->p_pwait, &p2->p_mtx, hz); - } - PROC_UNLOCK(p2); - - if (td->td_dbgflags & TDB_VFORK) { - PROC_LOCK(p); - if (p->p_ptevents & PTRACE_VFORK) - ptracestop(td, SIGTRAP, NULL); - td->td_dbgflags &= ~TDB_VFORK; - PROC_UNLOCK(p); - } - } + if (__predict_false(td->td_pflags & TDP_RFPPWAIT)) + fork_rfppwait(td); } Modified: head/sys/sys/proc.h ============================================================================== --- head/sys/sys/proc.h Wed Dec 19 20:25:58 2018 (r342235) +++ head/sys/sys/proc.h Wed Dec 19 20:27:26 2018 (r342236) @@ -1026,6 +1026,7 @@ int enterthispgrp(struct proc *p, struct pgrp *pgrp); void faultin(struct proc *p); void fixjobc(struct proc *p, struct pgrp *pgrp, int entering); int fork1(struct thread *, struct fork_req *); +void fork_rfppwait(struct thread *); void fork_exit(void (*)(void *, struct trapframe *), void *, struct trapframe *); void fork_return(struct thread *, struct trapframe *);