From patchwork Tue Jun 28 09:01:26 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peter Lieven X-Patchwork-Id: 641429 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3rf0MP3j84z9sCg for ; Tue, 28 Jun 2016 19:08:01 +1000 (AEST) Received: from localhost ([::1]:35190 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bHozv-0005gr-4X for incoming@patchwork.ozlabs.org; Tue, 28 Jun 2016 05:07:59 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:34627) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bHou6-0006dE-Nh for qemu-devel@nongnu.org; Tue, 28 Jun 2016 05:02:03 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bHou4-0003KD-TT for qemu-devel@nongnu.org; Tue, 28 Jun 2016 05:01:58 -0400 Received: from mx-v6.kamp.de ([2a02:248:0:51::16]:39176 helo=mx01.kamp.de) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bHou4-0003Ju-Jg for qemu-devel@nongnu.org; Tue, 28 Jun 2016 05:01:56 -0400 Received: (qmail 26332 invoked by uid 89); 28 Jun 2016 09:01:55 -0000 Received: from [195.62.97.28] by client-16-kamp (envelope-from , uid 89) with qmail-scanner-2010/03/19-MF (clamdscan: 0.99.2/21804. hbedv: 8.3.40.44/7.12.99.34. avast: 1.2.2/16062800. spamassassin: 3.4.1. 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Processed in 0.195415 secs); 28 Jun 2016 09:01:55 -0000 Received: from smtp.kamp.de (HELO submission.kamp.de) ([195.62.97.28]) by mx01.kamp.de with ESMTPS (DHE-RSA-AES256-GCM-SHA384 encrypted); 28 Jun 2016 09:01:52 -0000 X-GL_Whitelist: yes Received: (qmail 29630 invoked from network); 28 Jun 2016 09:01:47 -0000 Received: from lieven-pc.kamp-intra.net (HELO lieven-pc) (relay@kamp.de@::ffff:172.21.12.60) by submission.kamp.de with ESMTPS (DHE-RSA-AES256-GCM-SHA384 encrypted) ESMTPA; 28 Jun 2016 09:01:47 -0000 Received: by lieven-pc (Postfix, from userid 1000) id 426882084B; Tue, 28 Jun 2016 11:01:46 +0200 (CEST) From: Peter Lieven To: qemu-devel@nongnu.org Date: Tue, 28 Jun 2016 11:01:26 +0200 Message-Id: <1467104499-27517-3-git-send-email-pl@kamp.de> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1467104499-27517-1-git-send-email-pl@kamp.de> References: <1467104499-27517-1-git-send-email-pl@kamp.de> X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 2a02:248:0:51::16 Subject: [Qemu-devel] [PATCH 02/15] coroutine-ucontext: add a switch to monitor maximum stack size X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kwolf@redhat.com, peter.maydell@linaro.org, mst@redhat.com, Peter Lieven , dgilbert@redhat.com, mreitz@redhat.com, kraxel@redhat.com, pbonzini@redhat.com Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" this adds a debug configure switch to enable monitoring of the maximum used stack size by all coroutines. Signed-off-by: Peter Lieven --- configure | 18 ++++++++++++++++++ util/coroutine-ucontext.c | 40 ++++++++++++++++++++++++++++++++++++++++ 2 files changed, 58 insertions(+) diff --git a/configure b/configure index 5929aba..82bcc25 100755 --- a/configure +++ b/configure @@ -296,6 +296,7 @@ libiscsi="" libnfs="" coroutine="" coroutine_pool="" +coroutine_stack_size_debug="no" seccomp="" glusterfs="" glusterfs_xlator_opt="no" @@ -1004,6 +1005,8 @@ for opt do ;; --enable-coroutine-pool) coroutine_pool="yes" ;; + --enable-coroutine-stack-size-debug) coroutine_stack_size_debug="yes" + ;; --disable-docs) docs="no" ;; --enable-docs) docs="yes" @@ -1361,6 +1364,8 @@ disabled with --disable-FEATURE, default is enabled if available: (for reading bzip2-compressed dmg images) seccomp seccomp support coroutine-pool coroutine freelist (better performance) + coroutine-stack-size-debug + report coroutine max stack usage (only for debugging) glusterfs GlusterFS backend archipelago Archipelago backend tpm TPM support @@ -4298,6 +4303,15 @@ fi if test "$coroutine" = "gthread" -a "$coroutine_pool" = "yes"; then error_exit "'gthread' coroutine backend does not support pool (use --disable-coroutine-pool)" fi +if test "$coroutine_stack_size_debug" = "yes"; then + if test "$coroutine" != "ucontext"; then + error_exit "coroutine stack size debugging currently only works with ucontext" + fi + if test "$coroutine_pool" = "yes"; then + echo "WARN: disabling coroutine pool for stack size debugging" + coroutine_pool=no + fi +fi ########################################## # check if we have open_by_handle_at @@ -4866,6 +4880,7 @@ echo "QGA MSI support $guest_agent_msi" echo "seccomp support $seccomp" echo "coroutine backend $coroutine" echo "coroutine pool $coroutine_pool" +echo "coroutine stack size debug $coroutine_stack_size_debug" echo "GlusterFS support $glusterfs" echo "Archipelago support $archipelago" echo "gcov $gcov_tool" @@ -5335,6 +5350,9 @@ if test "$coroutine_pool" = "yes" ; then else echo "CONFIG_COROUTINE_POOL=0" >> $config_host_mak fi +if test "$coroutine_stack_size_debug" = "yes" ; then + echo "CONFIG_COROUTINE_STACK_SIZE_DEBUG=y" >> $config_host_mak +fi if test "$open_by_handle_at" = "yes" ; then echo "CONFIG_OPEN_BY_HANDLE=y" >> $config_host_mak diff --git a/util/coroutine-ucontext.c b/util/coroutine-ucontext.c index 841e7db..27c61f3 100644 --- a/util/coroutine-ucontext.c +++ b/util/coroutine-ucontext.c @@ -31,6 +31,10 @@ #include #endif +#ifdef CONFIG_COROUTINE_STACK_SIZE_DEBUG +#include "qemu/error-report.h" +#endif + typedef struct { Coroutine base; void *stack; @@ -48,6 +52,10 @@ typedef struct { static __thread CoroutineUContext leader; static __thread Coroutine *current; +#ifdef CONFIG_COROUTINE_STACK_SIZE_DEBUG +static uint32_t max_stack_usage; +#endif + /* * va_args to makecontext() must be type 'int', so passing * the pointer we need may require several int args. This @@ -88,6 +96,9 @@ Coroutine *qemu_coroutine_new(void) ucontext_t old_uc, uc; sigjmp_buf old_env; union cc_arg arg = {0}; +#ifdef CONFIG_COROUTINE_STACK_SIZE_DEBUG + void *ptr; +#endif /* The ucontext functions preserve signal masks which incurs a * system call overhead. sigsetjmp(buf, 0)/siglongjmp() does not @@ -118,6 +129,13 @@ Coroutine *qemu_coroutine_new(void) co->stack = g_malloc(stack_size); #endif +#ifdef CONFIG_COROUTINE_STACK_SIZE_DEBUG + for (ptr = co->stack + getpagesize(); + ptr < co->stack + COROUTINE_STACK_SIZE; ptr += sizeof(u_int32_t)) { + *(u_int32_t *)ptr = 0xdeadbeaf; + } +#endif + co->base.entry_arg = &old_env; /* stash away our jmp_buf */ uc.uc_link = &old_uc; @@ -161,6 +179,20 @@ void qemu_coroutine_delete(Coroutine *co_) { CoroutineUContext *co = DO_UPCAST(CoroutineUContext, base, co_); +#ifdef CONFIG_COROUTINE_STACK_SIZE_DEBUG + void *ptr; + for (ptr = co->stack + getpagesize(); + ptr < co->stack + COROUTINE_STACK_SIZE; ptr += sizeof(u_int32_t)) { + if (*(u_int32_t *)ptr != 0xdeadbeaf) { + break; + } + } + /* we only want to estimate the max stack usage, the OR will overestimate + * the stack usage, but this is ok here and avoids the usage of a mutex */ + atomic_or(&max_stack_usage, + COROUTINE_STACK_SIZE - (uintptr_t) (ptr - co->stack)); +#endif + #ifdef CONFIG_VALGRIND_H valgrind_stack_deregister(co); #endif @@ -210,3 +242,11 @@ bool qemu_in_coroutine(void) { return current && current->caller; } + +#ifdef CONFIG_COROUTINE_STACK_SIZE_DEBUG +static void __attribute__((destructor)) print_max_stack_usage(void) +{ + error_report("coroutine-ucontext: max stack usage was less or equal to " + "%"PRIu32" bytes.", max_stack_usage); +} +#endif