Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759401AbXHPMgi (ORCPT ); Thu, 16 Aug 2007 08:36:38 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754259AbXHPMga (ORCPT ); Thu, 16 Aug 2007 08:36:30 -0400 Received: from ra.tuxdriver.com ([70.61.120.52]:2106 "EHLO ra.tuxdriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754718AbXHPMg3 (ORCPT ); Thu, 16 Aug 2007 08:36:29 -0400 Date: Thu, 16 Aug 2007 08:35:38 -0400 From: Neil Horman To: linux-kernel@vger.kernel.org Cc: akpm@linux-foundation.org, torvalds@linux-foundation.org Subject: Re: [PATCH]: proc: export a processes resource limits via proc/ Message-ID: <20070816123538.GA10430@hmsreliant.think-freely.org> References: <20070813140044.GB1960@hmsreliant.think-freely.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20070813140044.GB1960@hmsreliant.think-freely.org> 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: 4528 Lines: 137 Hey again- Andrew requested that I repost this cleanly, after running the patch through checkpatch. As requested here it is with the changelog. Currently, there exists no method for a process to query the resource limits of another process. They can be inferred via some mechanisms but they cannot be explicitly determined. Given that this information can be usefull to know during the debugging of an application, I've written this patch which exports all of a processes limits via /proc//limits. Tested successfully by myself on x86 on top of 2.6.23-rc2-mm1. Thanks & Regards Neil Signed-off-by: Neil Horman base.c | 69 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 69 insertions(+) diff --git a/fs/proc/base.c b/fs/proc/base.c index ed2b224..4fb34a5 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 +324,72 @@ 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 +2084,7 @@ 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 +2378,7 @@ 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/