Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753667AbZJZQjN (ORCPT ); Mon, 26 Oct 2009 12:39:13 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752424AbZJZQjM (ORCPT ); Mon, 26 Oct 2009 12:39:12 -0400 Received: from mailgw.miraclelinux.com ([122.216.84.157]:52426 "EHLO mailgw.miraclelinux.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752283AbZJZQjL (ORCPT ); Mon, 26 Oct 2009 12:39:11 -0400 Message-ID: <4AE5D0B2.2050706@miraclelinux.com> Date: Tue, 27 Oct 2009 01:39:14 +0900 From: Naohiro Ooiwa User-Agent: Thunderbird 2.0.0.23 (Windows/20090812) MIME-Version: 1.0 To: Ingo Molnar CC: roland@redhat.com, akpm@linux-foundation.org, oleg@redhat.com, LKML , h-shimamoto@ct.jp.nec.com, Thomas Gleixner , Peter Zijlstra Subject: Re: [PATCH] show message when exceeded rlimit of pending signals References: <4AE1804A.2050404@miraclelinux.com> <20091023114600.GG5886@elte.hu> <4AE2A6A1.1070904@miraclelinux.com> <4AE2C151.8070006@miraclelinux.com> <20091024085848.GA23215@elte.hu> <4AE57745.8080701@miraclelinux.com> <20091026113800.GA9503@elte.hu> In-Reply-To: <20091026113800.GA9503@elte.hu> Content-Type: text/plain; charset=ISO-2022-JP Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3595 Lines: 116 Hi Ingo, Now that you mention it, I think so, too. I update my patch. How is the following patch. Could you please review it. Thanks you. Naohiro Ooiwa Signed-off-by: Naohiro Ooiwa --- Documentation/kernel-parameters.txt | 9 ++++++++- kernel/signal.c | 16 +++++++++++++--- 2 files changed, 21 insertions(+), 4 deletions(-) diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 9107b38..01c2723 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -2032,8 +2032,15 @@ and is between 256 and 4096 characters. It is defined in the file print-fatal-signals= [KNL] debug: print fatal signals + If you would like to know what the cause of a coredump + by signal number, if your working system may have + too many POSIX.1 timers, and when during the system + test,you may as well to enable this parameter. print-fatal-signals=1: print segfault info to - the kernel console. + the kernel console, and print caution that reached the + limit of pending signals to the kernel console. + When printed the caution messages, you can try + "ulimit -i unlimited". default: off. printk.time= Show timing data prefixed to each printk message line diff --git a/kernel/signal.c b/kernel/signal.c index 6705320..137112e 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -188,6 +188,14 @@ int next_signal(struct sigpending *pending, sigset_t *mask) return sig; } +int print_fatal_signals; + +static void show_reach_rlimit_sigpending(void) +{ + if (printk_ratelimit()) + printk(KERN_WARNING "%s/%d: reached the limit of pending signals.\n", current->comm, current->pid); +} + /* * allocate a new signal queue record * - this may be called without locks if and only if t == current, otherwise an @@ -209,8 +217,12 @@ static struct sigqueue *__sigqueue_alloc(struct task_struct *t, gfp_t flags, atomic_inc(&user->sigpending); if (override_rlimit || atomic_read(&user->sigpending) <= - t->signal->rlim[RLIMIT_SIGPENDING].rlim_cur) + t->signal->rlim[RLIMIT_SIGPENDING].rlim_cur) { q = kmem_cache_alloc(sigqueue_cachep, flags); + } else { + if (print_fatal_signals) + show_reach_rlimit_sigpending(); + } if (unlikely(q == NULL)) { atomic_dec(&user->sigpending); free_uid(user); @@ -925,8 +937,6 @@ static int send_signal(int sig, struct siginfo *info, struct task_struct *t, return __send_signal(sig, info, t, group, from_ancestor_ns); } -int print_fatal_signals; - static void print_fatal_signal(struct pt_regs *regs, int signr) { printk("%s/%d: potentially unexpected fatal signal %d.\n", -- 1.5.4.1 Ingo Molnar wrote: > * nooiwa wrote: > >> +++ b/kernel/sysctl.c >> @@ -67,6 +67,7 @@ static int deprecated_sysctl_warning(struct __sysctl_args *args); >> /* External variables not in a header file. */ >> extern int C_A_D; >> extern int print_fatal_signals; >> +extern int print_reach_rlimit_sigpending; > > Ooiwa-san, Roland, Andrew - what do you think about just making this > part of the existing print_fatal_signals flag, instead of adding a new > one? > > Signal queue overflows are a 'fatal', signal-related condition as well - > we lose a signal in essence. The patch would be smaller as well. > > Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/