From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.7 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 15DC2C2D0E5 for ; Fri, 27 Mar 2020 17:06:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E13B72076B for ; Fri, 27 Mar 2020 17:06:07 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=shutemov-name.20150623.gappssmtp.com header.i=@shutemov-name.20150623.gappssmtp.com header.b="z3j+Mugv" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727831AbgC0RGG (ORCPT ); Fri, 27 Mar 2020 13:06:06 -0400 Received: from mail-lf1-f66.google.com ([209.85.167.66]:37528 "EHLO mail-lf1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726770AbgC0RGG (ORCPT ); Fri, 27 Mar 2020 13:06:06 -0400 Received: by mail-lf1-f66.google.com with SMTP id j11so8474915lfg.4 for ; Fri, 27 Mar 2020 10:06:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=shutemov-name.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=uEmPFiw3NMkf3IfRIxWgnKIkN+OrB/j1csttn5Htb5E=; b=z3j+MugvIOEV5ZTNeV8Y5iSCTsByA3McfeDK2HMga5j30TJGS1jCU2mARtvWuwgHZT wBwryyzEC9XH8i28e+3+RHU3jD6Q86e2Y7N/2LASbsk4xhgGhE/LKp0YxH614uxCaLm2 Uxb43/hP9GUS78Cz+RGLCxlp/k0xwNjWmpLM/AY1ydd0ToWnqmkTAkioJShsGdnUnmIq KDHOOiJRSvG43K61Vm4lBM4R+aHhWi5VCLrVpWl0+Xy9KMLWv5aei3nbPj/r3QC5WhNR oOxCPsb+UmkK4aAszIDPTddUV08oDFX+pDtf6D7W6u5qb88ypahuJSlTJ0irMeO6isQL UEHQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=uEmPFiw3NMkf3IfRIxWgnKIkN+OrB/j1csttn5Htb5E=; b=RGD37FKFppKM58uk931ABI+6RZOQyrnxEdKjwO1og9jZLJWrHRQe30HMPsH4BiMExt R36BXZueczgTrEUP9NYWULFnpGQutV93+aUbRjmeJVfX7uXNL+iZ5U54uapLVEaFtKpq N8FbrzFPQ41/5dRl8+vqsLeIWXk3PEMKt8JOTEwATxRAju6yepYtDHuMs2jFWcLm4QET g5AQuFDbLmDDI+R0vD0A8vYW4qSCr3bq4W6quGKqrT0rfIja3tnWLq3FUAt78UrCDhEE jY1RchnPI8tW2jOWI/gMhlwVihnKeKybUJvUObRG7eaD0e31gu5gQRWeGiiaRibc7PpM cNDw== X-Gm-Message-State: AGi0PuZ6iVpua2nMKCV5SoJ0W+QvPES9vrxDyghB/P3kOdFYGW30F2Ac iB2J9/AXfUpLJaEgOLFxJ2NPMw== X-Google-Smtp-Source: APiQypI3S8W00hxoDxa3oFcnVq3mUYLKs3IlsAXA0vKYmfajc3bCUm9dNAKtZxa0tJ1SdtOMPJlmlg== X-Received: by 2002:a19:4f01:: with SMTP id d1mr184636lfb.182.1585328764571; Fri, 27 Mar 2020 10:06:04 -0700 (PDT) Received: from box.localdomain ([86.57.175.117]) by smtp.gmail.com with ESMTPSA id c5sm3225046lfg.82.2020.03.27.10.06.03 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 27 Mar 2020 10:06:03 -0700 (PDT) From: "Kirill A. Shutemov" X-Google-Original-From: "Kirill A. Shutemov" Received: by box.localdomain (Postfix, from userid 1000) id 699D3100D28; Fri, 27 Mar 2020 20:06:07 +0300 (+03) To: akpm@linux-foundation.org, Andrea Arcangeli Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, "Kirill A. Shutemov" Subject: [PATCH 3/7] khugepaged: Drain LRU add pagevec to get rid of extra pins Date: Fri, 27 Mar 2020 20:05:57 +0300 Message-Id: <20200327170601.18563-4-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 2.26.0 In-Reply-To: <20200327170601.18563-1-kirill.shutemov@linux.intel.com> References: <20200327170601.18563-1-kirill.shutemov@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org __collapse_huge_page_isolate() may fail due to extra pin in the LRU add pagevec. It's petty common for swapin case: we swap in pages just to fail due to the extra pin. Signed-off-by: Kirill A. Shutemov --- mm/khugepaged.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/mm/khugepaged.c b/mm/khugepaged.c index 14d7afc90786..39e0994abeb8 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -585,11 +585,19 @@ static int __collapse_huge_page_isolate(struct vm_area_struct *vma, * The page must only be referenced by the scanned process * and page swap cache. */ + if (page_count(page) != 1 + PageSwapCache(page)) { + /* + * Drain pagevec and retry just in case we can get rid + * of the extra pin, like in swapin case. + */ + lru_add_drain(); + } if (page_count(page) != 1 + PageSwapCache(page)) { unlock_page(page); result = SCAN_PAGE_COUNT; goto out; } + if (pte_write(pteval)) { writable = true; } else { -- 2.26.0