From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751114AbeBQIPt (ORCPT ); Sat, 17 Feb 2018 03:15:49 -0500 Received: from forwardcorp1j.cmail.yandex.net ([5.255.227.105]:52021 "EHLO forwardcorp1j.cmail.yandex.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751087AbeBQIPs (ORCPT ); Sat, 17 Feb 2018 03:15:48 -0500 Authentication-Results: smtpcorp1p.mail.yandex.net; dkim=pass header.i=@yandex-team.ru Subject: [PATCH] Documentation/vm/pagemap.txt: document bit WAITERS From: Konstantin Khlebnikov To: linux-mm@kvack.org, Andrew Morton Cc: linux-kernel@vger.kernel.org Date: Sat, 17 Feb 2018 11:15:43 +0300 Message-ID: <151885534363.17898.8456668269733387066.stgit@buzz> In-Reply-To: <151834540184.176427.12174649162560874101.stgit@buzz> References: <151834540184.176427.12174649162560874101.stgit@buzz> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Signed-off-by: Konstantin Khlebnikov --- Documentation/vm/pagemap.txt | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/Documentation/vm/pagemap.txt b/Documentation/vm/pagemap.txt index eafcefa15261..eaa46771fa30 100644 --- a/Documentation/vm/pagemap.txt +++ b/Documentation/vm/pagemap.txt @@ -71,6 +71,7 @@ There are four components to pagemap: 23. BALLOON 24. ZERO_PAGE 25. IDLE + 26. WAITERS * /proc/kpagecgroup. This file contains a 64-bit inode number of the memory cgroup each page is charged to, indexed by PFN. Only available when @@ -127,6 +128,13 @@ Short descriptions to the page flags: stale in case the page was accessed via a PTE. To make sure the flag is up-to-date one has to read /sys/kernel/mm/page_idle/bitmap first. +26. WAITERS + Indicates tasks are waiting when bits LOCKED or WRITEBACK will be cleared. + They might be blocked by undergoing IO or by contention on page lock. + Bit WAITERS might be false-positive, in this case next clear of LOCKED or + WRITEBACK will clear WAITERS too. I.e. without LOCKED and WRITEBACK it's + false-positive for sure. + [IO related page flags] 1. ERROR IO error occurred 3. UPTODATE page has up-to-date data