Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750894AbaLORQn (ORCPT ); Mon, 15 Dec 2014 12:16:43 -0500 Received: from mail-wg0-f52.google.com ([74.125.82.52]:63264 "EHLO mail-wg0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750783AbaLORQk (ORCPT ); Mon, 15 Dec 2014 12:16:40 -0500 From: Petr Cermak To: linux-kernel@vger.kernel.org Cc: Petr Cermak , linux-mm@kvack.org, Andrew Morton , Bjorn Helgaas , Primiano Tucci Subject: [PATCH 2/2] task_mmu: Add user-space support for resetting mm->hiwater_rss (peak RSS) Date: Mon, 15 Dec 2014 17:15:33 +0000 Message-Id: <1418663733-15949-1-git-send-email-petrcermak@chromium.org> X-Mailer: git-send-email 2.2.0.rc0.207.ga3a616c References: <1418223544-11382-1-git-send-email-petrcermak@chromium.org> In-Reply-To: <1418223544-11382-1-git-send-email-petrcermak@chromium.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. Cc: linux-mm@kvack.org Cc: Andrew Morton Cc: Bjorn Helgaas Cc: Primiano Tucci Cc: Petr Cermak Signed-off-by: Petr Cermak --- Documentation/filesystems/proc.txt | 3 +++ fs/proc/task_mmu.c | 15 ++++++++++++++- include/linux/mm.h | 5 +++++ 3 files changed, 22 insertions(+), 1 deletion(-) diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt index aae9dd1..eab62e3 100644 --- a/Documentation/filesystems/proc.txt +++ b/Documentation/filesystems/proc.txt @@ -488,6 +488,9 @@ To clear the bits for the file mapped pages associated with the process To clear the soft-dirty bit > echo 4 > /proc/PID/clear_refs +To reset the peak resident set size ("high water mark") + > echo 5 > /proc/PID/clear_refs + Any other value written to /proc/PID/clear_refs will have no effect. The /proc/pid/pagemap gives the PFN, which can be used to find the pageflags diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 3ee8541..7967535 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -747,6 +747,7 @@ enum clear_refs_types { CLEAR_REFS_ANON, CLEAR_REFS_MAPPED, CLEAR_REFS_SOFT_DIRTY, + CLEAR_REFS_MM_HIWATER_RSS, CLEAR_REFS_LAST, }; @@ -855,6 +856,17 @@ static ssize_t clear_refs_write(struct file *file, const char __user *buf, if (!mm) goto out_task; + if (type == CLEAR_REFS_MM_HIWATER_RSS) { + /* + * Writing 5 to /proc/pid/clear_refs resets the peak resident + * set size. + */ + down_write(&mm->mmap_sem); + reset_mm_hiwater_rss(mm); + up_write(&mm->mmap_sem); + goto out_mm; + } + struct clear_refs_private cp = { .type = type, }; @@ -904,8 +916,9 @@ static ssize_t clear_refs_write(struct file *file, const char __user *buf, mmu_notifier_invalidate_range_end(mm, 0, -1); flush_tlb_mm(mm); up_read(&mm->mmap_sem); - mmput(mm); +out_mm: + mmput(mm); out_task: put_task_struct(task); diff --git a/include/linux/mm.h b/include/linux/mm.h index c0a67b8..f3f6cee 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1368,6 +1368,11 @@ static inline void update_hiwater_vm(struct mm_struct *mm) mm->hiwater_vm = mm->total_vm; } +static inline void reset_mm_hiwater_rss(struct mm_struct *mm) +{ + mm->hiwater_rss = get_mm_rss(mm); +} + static inline void setmax_mm_hiwater_rss(unsigned long *maxrss, struct mm_struct *mm) { -- 2.2.0.rc0.207.ga3a616c -- 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/