From patchwork Mon May 6 15:53:43 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Joel Savitz X-Patchwork-Id: 10931361 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 5DC9C13AD for ; Mon, 6 May 2019 15:53:59 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4BF902881B for ; Mon, 6 May 2019 15:53:59 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 3FC842881E; Mon, 6 May 2019 15:53:59 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id DE43D2881B for ; Mon, 6 May 2019 15:53:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726670AbfEFPx6 (ORCPT ); Mon, 6 May 2019 11:53:58 -0400 Received: from mx1.redhat.com ([209.132.183.28]:3346 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726321AbfEFPx6 (ORCPT ); Mon, 6 May 2019 11:53:58 -0400 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 7C482306D334; Mon, 6 May 2019 15:53:57 +0000 (UTC) Received: from jsavitz.bos.com (dhcp-17-161.bos.redhat.com [10.18.17.161]) by smtp.corp.redhat.com (Postfix) with ESMTP id 3793560BEC; Mon, 6 May 2019 15:53:48 +0000 (UTC) From: Joel Savitz To: linux-kernel@vger.kernel.org Cc: Joel Savitz , Alexey Dobriyan , Andrew Morton , Vlastimil Babka , "Aneesh Kumar K.V" , Michael Ellerman , Ram Pai , Andrea Arcangeli , Huang Ying , Sandeep Patil , Rafael Aquini , Yury Norov , linux-fsdevel@vger.kernel.org Subject: [PATCH v3] fs/proc: add VmTaskSize field to /proc/$$/status Date: Mon, 6 May 2019 11:53:43 -0400 Message-Id: <1557158023-23021-1-git-send-email-jsavitz@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.47]); Mon, 06 May 2019 15:53:58 +0000 (UTC) Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP There is currently no easy and architecture-independent way to find the lowest unusable virtual address available to a process without brute-force calculation. This patch allows a user to easily retrieve this value via /proc//status. Using this patch, any program that previously needed to waste cpu cycles recalculating a non-sensitive process-dependent value already known to the kernel can now be optimized to use this mechanism. Signed-off-by: Joel Savitz Acked-by: Rafael Aquini --- Documentation/filesystems/proc.txt | 2 ++ fs/proc/task_mmu.c | 2 ++ 2 files changed, 4 insertions(+) diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt index 66cad5c86171..1c6a912e3975 100644 --- a/Documentation/filesystems/proc.txt +++ b/Documentation/filesystems/proc.txt @@ -187,6 +187,7 @@ read the file /proc/PID/status: VmLib: 1412 kB VmPTE: 20 kb VmSwap: 0 kB + VmTaskSize: 137438953468 kB HugetlbPages: 0 kB CoreDumping: 0 THP_enabled: 1 @@ -263,6 +264,7 @@ Table 1-2: Contents of the status files (as of 4.19) VmPTE size of page table entries VmSwap amount of swap used by anonymous private data (shmem swap usage is not included) + VmTaskSize lowest unusable address in process virtual memory HugetlbPages size of hugetlb memory portions CoreDumping process's memory is currently being dumped (killing the process may lead to a corrupted core) diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 95ca1fe7283c..0af7081f7b19 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -74,6 +74,8 @@ void task_mem(struct seq_file *m, struct mm_struct *mm) seq_put_decimal_ull_width(m, " kB\nVmPTE:\t", mm_pgtables_bytes(mm) >> 10, 8); SEQ_PUT_DEC(" kB\nVmSwap:\t", swap); + seq_put_decimal_ull_width(m, + " kB\nVmTaskSize:\t", mm->task_size >> 10, 8); seq_puts(m, " kB\n"); hugetlb_report_usage(m, mm); }