Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751602AbaLQWaN (ORCPT ); Wed, 17 Dec 2014 17:30:13 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:43370 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751189AbaLQWaL (ORCPT ); Wed, 17 Dec 2014 17:30:11 -0500 Date: Wed, 17 Dec 2014 14:30:10 -0800 From: Andrew Morton To: Petr Cermak Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Bjorn Helgaas , Primiano Tucci Subject: Re: [PATCH 2/2] task_mmu: Add user-space support for resetting mm->hiwater_rss (peak RSS) Message-Id: <20141217143010.ccf73cbd544ade86bb4dec3f@linux-foundation.org> In-Reply-To: <1418663733-15949-1-git-send-email-petrcermak@chromium.org> References: <1418223544-11382-1-git-send-email-petrcermak@chromium.org> <1418663733-15949-1-git-send-email-petrcermak@chromium.org> X-Mailer: Sylpheed 3.4.0beta7 (GTK+ 2.24.23; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 15 Dec 2014 17:15:33 +0000 Petr Cermak wrote: > Peak resident size of a process can be reset by writing "5" to > /proc/pid/clear_refs. The driving use-case for this would be getting the > peak RSS value, which can be retrieved from the VmHWM field in > /proc/pid/status, per benchmark iteration or test scenario. The term "reset" is ambiguous - it often means "reset it to zero". This? --- a/Documentation/filesystems/proc.txt~task_mmu-add-user-space-support-for-resetting-mm-hiwater_rss-peak-rss-fix +++ a/Documentation/filesystems/proc.txt @@ -488,7 +488,8 @@ To clear the bits for the file mapped pa To clear the soft-dirty bit > echo 4 > /proc/PID/clear_refs -To reset the peak resident set size ("high water mark") +To reset the peak resident set size ("high water mark") to the process's +current value: > echo 5 > /proc/PID/clear_refs Any other value written to /proc/PID/clear_refs will have no effect. --- a/fs/proc/task_mmu.c~task_mmu-add-user-space-support-for-resetting-mm-hiwater_rss-peak-rss-fix +++ a/fs/proc/task_mmu.c @@ -859,7 +859,7 @@ static ssize_t clear_refs_write(struct f if (type == CLEAR_REFS_MM_HIWATER_RSS) { /* * Writing 5 to /proc/pid/clear_refs resets the peak resident - * set size. + * set size to this mm's current rss value. */ down_write(&mm->mmap_sem); reset_mm_hiwater_rss(mm); _ -- 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/