Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S939811AbXHMX7f (ORCPT ); Mon, 13 Aug 2007 19:59:35 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753309AbXHMX7R (ORCPT ); Mon, 13 Aug 2007 19:59:17 -0400 Received: from ra.tuxdriver.com ([70.61.120.52]:4983 "EHLO ra.tuxdriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753961AbXHMX7O (ORCPT ); Mon, 13 Aug 2007 19:59:14 -0400 Date: Mon, 13 Aug 2007 19:58:02 -0400 From: Neil Horman To: Alexey Dobriyan Cc: Ingo Oeser , linux-kernel@vger.kernel.org, akpm@linux-foundation.org, torvalds@linux-foundation.org Subject: Re: [PATCH]: proc: export a processes resource limits via proc/ Message-ID: <20070813235802.GA20093@hmsreliant.think-freely.org> References: <20070813140044.GB1960@hmsreliant.think-freely.org> <200708132125.47188.ioe-lkml@rameria.de> <20070813201130.GD1960@hmsreliant.think-freely.org> <20070813210402.GB5870@martell.zuzino.mipt.ru> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20070813210402.GB5870@martell.zuzino.mipt.ru> User-Agent: Mutt/1.5.12-2006-07-14 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6717 Lines: 201 On Tue, Aug 14, 2007 at 01:04:02AM +0400, Alexey Dobriyan wrote: > On Mon, Aug 13, 2007 at 04:11:30PM -0400, Neil Horman wrote: > > --- a/fs/proc/base.c > > +++ b/fs/proc/base.c > > @@ -323,6 +324,68 @@ static int proc_oom_score(struct task_struct *task, char *buffer) > > return sprintf(buffer, "%lu\n", points); > > } > > > > +struct limit_names { > > + char *name; > > + char *unit; > > +}; > > + > > +static const struct limit_names lnames[RLIM_NLIMITS] = { > > + [RLIMIT_CPU] = {"Max cpu time", "ms"}, > > + [RLIMIT_FSIZE] = {"Max file size", "bytes"}, > > + [RLIMIT_DATA] = {"Max data size", "bytes"}, > > + [RLIMIT_STACK] = {"Max stack size", "bytes"}, > > + [RLIMIT_CORE] = {"Max core file size", "bytes"}, > > + [RLIMIT_RSS] = {"Max resident set", "bytes"}, > > + [RLIMIT_NPROC] = {"Max processes", "processes"}, > > + [RLIMIT_NOFILE] = {"Max open files", "files"}, > > + [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"}, > > + [RLIMIT_AS] = {"Max address space", "bytes"}, > > + [RLIMIT_LOCKS] = {"Max file locks", "locks"}, > > + [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"}, > > this and processes should be left empty methinks, because max signals is > in fact unitless. > not sure I agree with that. According to the man page, RLIMIT_SIGPENDING is counted in number of signals and RLIMIT_NPROC is counted as a number of processes. > > + [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"}, > > + [RLIMIT_NICE] = {"Max nice priority", NULL}, > > + [RLIMIT_RTPRIO] = {"Max realtime priority", NULL}, > > +}; > > aha! trailing whitespace! > Fixed :) > > +static int proc_pid_limits(struct task_struct *task, char *buffer) > > +{ > > + unsigned int i; > > + int count = 0; > > + char *bufptr = buffer; > > + > > + struct rlimit rlim[RLIM_NLIMITS]; > > + > > + read_lock(&tasklist_lock); > > + memcpy(rlim, task->signal->rlim, (sizeof(struct rlimit) * RLIM_NLIMITS)); > > unneeded (, ) > I prefer to explicitly show order of operations, but I'm wierd that way, so I'll change it :) > > + read_unlock(&tasklist_lock); > > hmm, fork copies this under task lock of group leader and system calls > in sys.c too. What's up? > > I'm sure it will give you nonsensical output because of wrong locks but > I haven't checked. > I don't think so, I borrowed the code there from sys_getrlimit, which also reds task->signal->rlim (only for one element instead of the whole array, so if its broken here it should be broken there, but I don't see how. > FWIW, it survived ~1 hour of cat /proc/*/limits, mini fork bombs, LTP, > gdb testsuite and one sooper sikrit proggie. on core2 > Its survived for a few days for me (while true; do cat /proc/*/limits;done), with not noticible side effects (other than a slightly higher CPU load :)). New patch with the ()'s and whitespace fixed. Regards Neil Signed-off-by: Neil Horman base.c | 65 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 65 insertions(+) diff --git a/fs/proc/base.c b/fs/proc/base.c index ed2b224..b3ddf08 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -74,6 +74,7 @@ #include #include #include +#include #include "internal.h" /* NOTE: @@ -323,6 +324,68 @@ static int proc_oom_score(struct task_struct *task, char *buffer) return sprintf(buffer, "%lu\n", points); } +struct limit_names { + char *name; + char *unit; +}; + +static const struct limit_names lnames[RLIM_NLIMITS] = { + [RLIMIT_CPU] = {"Max cpu time", "ms"}, + [RLIMIT_FSIZE] = {"Max file size", "bytes"}, + [RLIMIT_DATA] = {"Max data size", "bytes"}, + [RLIMIT_STACK] = {"Max stack size", "bytes"}, + [RLIMIT_CORE] = {"Max core file size", "bytes"}, + [RLIMIT_RSS] = {"Max resident set", "bytes"}, + [RLIMIT_NPROC] = {"Max processes", "processes"}, + [RLIMIT_NOFILE] = {"Max open files", "files"}, + [RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"}, + [RLIMIT_AS] = {"Max address space", "bytes"}, + [RLIMIT_LOCKS] = {"Max file locks", "locks"}, + [RLIMIT_SIGPENDING] = {"Max pending signals", "signals"}, + [RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"}, + [RLIMIT_NICE] = {"Max nice priority", NULL}, + [RLIMIT_RTPRIO] = {"Max realtime priority", NULL}, +}; + +/* Display limits for a process */ +static int proc_pid_limits(struct task_struct *task, char *buffer) +{ + unsigned int i; + int count = 0; + char *bufptr = buffer; + + struct rlimit rlim[RLIM_NLIMITS]; + + read_lock(&tasklist_lock); + memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS); + read_unlock(&tasklist_lock); + + /* + * print the file header + */ + count += sprintf(&bufptr[count], "%-25s %-20s %-20s %-10s\n", + "Limit","Soft Limit","Hard Limit","Units"); + + for (i=0; i < RLIM_NLIMITS; i++) { + if (rlim[i].rlim_cur == RLIM_INFINITY) + count += sprintf(&bufptr[count], "%-25s %-20s ", lnames[i].name,"unlimited"); + else + count += sprintf(&bufptr[count], "%-25s %-20lu ", lnames[i].name, rlim[i].rlim_cur); + + if (rlim[i].rlim_max == RLIM_INFINITY) + count += sprintf(&bufptr[count], "%-20s ","unlimited"); + else + count += sprintf(&bufptr[count], "%-20lu ", rlim[i].rlim_max); + + if (lnames[i].unit) + count += sprintf(&bufptr[count],"%-10s\n", lnames[i].unit); + else + count += sprintf(&bufptr[count],"\n"); + } + + return count; +} + /************************************************************************/ /* Here the fs part begins */ /************************************************************************/ @@ -2017,6 +2080,7 @@ static const struct pid_entry tgid_base_stuff[] = { INF("environ", S_IRUSR, pid_environ), INF("auxv", S_IRUSR, pid_auxv), INF("status", S_IRUGO, pid_status), + INF("limits", S_IRUSR, pid_limits), #ifdef CONFIG_SCHED_DEBUG REG("sched", S_IRUGO|S_IWUSR, pid_sched), #endif @@ -2310,6 +2374,7 @@ static const struct pid_entry tid_base_stuff[] = { INF("environ", S_IRUSR, pid_environ), INF("auxv", S_IRUSR, pid_auxv), INF("status", S_IRUGO, pid_status), + INF("limits", S_IRUSR, pid_limits), #ifdef CONFIG_SCHED_DEBUG REG("sched", S_IRUGO|S_IWUSR, pid_sched), #endif -- /*************************************************** *Neil Horman *Software Engineer *Red Hat, Inc. *nhorman@tuxdriver.com *gpg keyid: 1024D / 0x92A74FA1 *http://pgp.mit.edu ***************************************************/ - 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/