From owner-svn-src-head@freebsd.org Mon Dec 2 22:34:19 2019 Return-Path: Delivered-To: svn-src-head@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id ADBA61BAA95; Mon, 2 Dec 2019 22:34:19 +0000 (UTC) (envelope-from jeff@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 47Rfzv49R2z4V26; Mon, 2 Dec 2019 22:34:19 +0000 (UTC) (envelope-from jeff@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 7270D618C; Mon, 2 Dec 2019 22:34:19 +0000 (UTC) (envelope-from jeff@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id xB2MYJ8q039439; Mon, 2 Dec 2019 22:34:19 GMT (envelope-from jeff@FreeBSD.org) Received: (from jeff@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id xB2MYJrQ039438; Mon, 2 Dec 2019 22:34:19 GMT (envelope-from jeff@FreeBSD.org) Message-Id: <201912022234.xB2MYJrQ039438@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: jeff set sender to jeff@FreeBSD.org using -f From: Jeff Roberson Date: Mon, 2 Dec 2019 22:34:19 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r355311 - head/sys/x86/x86 X-SVN-Group: head X-SVN-Commit-Author: jeff X-SVN-Commit-Paths: head/sys/x86/x86 X-SVN-Commit-Revision: 355311 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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: Mon, 02 Dec 2019 22:34:19 -0000 Author: jeff Date: Mon Dec 2 22:34:19 2019 New Revision: 355311 URL: https://svnweb.freebsd.org/changeset/base/355311 Log: Don't run sched_preempt() inside of an extra critical section. This disables the sched_preempt() switch optimization and causes the sched lock to be dropped and immediately reacquired. Reviewed by: jhb, kib, mav, markj (with changes) Differential Revision: https://reviews.freebsd.org/D22623 Modified: head/sys/x86/x86/mp_x86.c Modified: head/sys/x86/x86/mp_x86.c ============================================================================== --- head/sys/x86/x86/mp_x86.c Mon Dec 2 22:15:26 2019 (r355310) +++ head/sys/x86/x86/mp_x86.c Mon Dec 2 22:34:19 2019 (r355311) @@ -1261,18 +1261,11 @@ ipi_bitmap_handler(struct trapframe frame) int cpu = PCPU_GET(cpuid); u_int ipi_bitmap; - critical_enter(); td = curthread; td->td_intr_nesting_level++; oldframe = td->td_intr_frame; td->td_intr_frame = &frame; ipi_bitmap = atomic_readandclear_int(&cpuid_to_pcpu[cpu]->pc_ipi_bitmap); - if (ipi_bitmap & (1 << IPI_PREEMPT)) { -#ifdef COUNT_IPIS - (*ipi_preempt_counts[cpu])++; -#endif - sched_preempt(td); - } if (ipi_bitmap & (1 << IPI_AST)) { #ifdef COUNT_IPIS (*ipi_ast_counts[cpu])++; @@ -1280,14 +1273,23 @@ ipi_bitmap_handler(struct trapframe frame) /* Nothing to do for AST */ } if (ipi_bitmap & (1 << IPI_HARDCLOCK)) { + critical_enter(); #ifdef COUNT_IPIS (*ipi_hardclock_counts[cpu])++; #endif hardclockintr(); + critical_exit(); } + + /* Run preempt after clock handlers since it may switch. */ + if (ipi_bitmap & (1 << IPI_PREEMPT)) { +#ifdef COUNT_IPIS + (*ipi_preempt_counts[cpu])++; +#endif + sched_preempt(td); + } td->td_intr_frame = oldframe; td->td_intr_nesting_level--; - critical_exit(); } /*