Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751222Ab0HREvL (ORCPT ); Wed, 18 Aug 2010 00:51:11 -0400 Received: from cantor.suse.de ([195.135.220.2]:39307 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750828Ab0HREvH (ORCPT ); Wed, 18 Aug 2010 00:51:07 -0400 From: Nikanth Karthikesan Organization: suse.de To: Matt Mackall Subject: Re: [PATCH] Export mlock information via smaps Date: Wed, 18 Aug 2010 10:23:41 +0530 User-Agent: KMail/1.12.4 (Linux/2.6.31.12-0.2-default; KDE/4.3.5; x86_64; ; ) Cc: Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org References: <201008171039.31070.knikanth@suse.de> <1282062336.10679.226.camel@calx> In-Reply-To: <1282062336.10679.226.camel@calx> MIME-Version: 1.0 Content-Type: Text/Plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <201008181023.41378.knikanth@suse.de> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2985 Lines: 78 On Tuesday 17 August 2010 21:55:36 Matt Mackall wrote: > On Tue, 2010-08-17 at 10:39 +0530, Nikanth Karthikesan wrote: > > Currently there is no way to find whether a process has locked its pages > > in memory or not. And which of the memory regions are locked in memory. > > > > Add a new field to perms field 'l' to export this information. The > > information exported via maps file is not changed. > > I'm worried that your new 'l' flag will fatally surprise some naive > parser of this file. > So how to proceed? Create another "ssmaps" file or something? :) Or is the following patch any better? Even the "Yes"/"No" could be changed to "0 kB" or "x kB", if it would make it better. Thanks Nikanth Currently there is no way to find whether a process has locked its pages in memory or not. And which of the memory regions are locked in memory. Add a new field "Locked" to export this information via smaps file. Signed-off-by: Nikanth Karthikesan --- diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt index a6aca87..6eafd26 100644 --- a/Documentation/filesystems/proc.txt +++ b/Documentation/filesystems/proc.txt @@ -373,6 +373,7 @@ Referenced: 892 kB Swap: 0 kB KernelPageSize: 4 kB MMUPageSize: 4 kB +Locked: No The first of these lines shows the same information as is displayed for the mapping in /proc/PID/maps. The remaining lines show the size of the mapping, @@ -397,6 +398,8 @@ To clear the bits for the file mapped pages associated with the process > echo 3 > /proc/PID/clear_refs Any other value written to /proc/PID/clear_refs will have no effect. +The "Locked" indicates whether the mapping is locked in memory or not. + 1.2 Kernel data --------------- diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index aea1d3f..7bafbcf 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -405,7 +405,8 @@ static int show_smap(struct seq_file *m, void *v) "Referenced: %8lu kB\n" "Swap: %8lu kB\n" "KernelPageSize: %8lu kB\n" - "MMUPageSize: %8lu kB\n", + "MMUPageSize: %8lu kB\n" + "Locked: %s\n", (vma->vm_end - vma->vm_start) >> 10, mss.resident >> 10, (unsigned long)(mss.pss >> (10 + PSS_SHIFT)), @@ -416,7 +417,8 @@ static int show_smap(struct seq_file *m, void *v) mss.referenced >> 10, mss.swap >> 10, vma_kernel_pagesize(vma) >> 10, - vma_mmu_pagesize(vma) >> 10); + vma_mmu_pagesize(vma) >> 10, + (vma->vm_flags & VM_LOCKED) ? "Yes" : "No"); if (m->count < m->size) /* vma is copied successfully */ m->version = (vma != get_gate_vma(task)) ? vma->vm_start : 0; -- 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/