From patchwork Sat Aug 7 02:21:29 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nico Pache X-Patchwork-Id: 12424075 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=-13.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 A95BDC4338F for ; Sat, 7 Aug 2021 02:21:51 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 3B44361167 for ; Sat, 7 Aug 2021 02:21:51 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 3B44361167 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id 9E3058D0001; Fri, 6 Aug 2021 22:21:50 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 9930B6B0071; Fri, 6 Aug 2021 22:21:50 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 8A9368D0001; Fri, 6 Aug 2021 22:21:50 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 6E8C36B006C for ; Fri, 6 Aug 2021 22:21:50 -0400 (EDT) Received: from smtpin09.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 038661F232 for ; Sat, 7 Aug 2021 02:21:49 +0000 (UTC) X-FDA: 78446683980.09.815D8F0 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by imf27.hostedemail.com (Postfix) with ESMTP id 945C070148EC for ; Sat, 7 Aug 2021 02:21:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1628302909; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=Q+7cG7xhRyIP8KFqGqqBfTmxfpmvZcxdghzXKqssv0Y=; b=MhZPj45bEBg7ronpsKDD6fbpYKPc8czUTnZuYARW52UTX89RL1tjiyar4p0C+3yOBre+H1 vIm96N86G0sV3thfMBIFx5SLJ2KQzVXlHweCUypl4tagfwNKhsJkitkyPteBYtE4igJ7xF XFCSijwnvUdY2IGD5plyekIbiB8rY1U= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-8-PwD0IpJLOpqWA9RHngli0g-1; Fri, 06 Aug 2021 22:21:47 -0400 X-MC-Unique: PwD0IpJLOpqWA9RHngli0g-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 587521853025; Sat, 7 Aug 2021 02:21:46 +0000 (UTC) Received: from localhost.localdomain.com (unknown [10.22.16.16]) by smtp.corp.redhat.com (Postfix) with ESMTP id 46CF627C47; Sat, 7 Aug 2021 02:21:41 +0000 (UTC) From: Nico Pache To: linux-mm@kvack.org, akpm@linux-foundation.org, linux-kernel@vger.kernel.org Cc: hannes@cmpxchg.org, npache@redhat.com, aquini@redhat.com, shakeelb@google.com, llong@redhat.com Subject: [PATCH v2] vm_swappiness=0 should still try to avoid swapping anon memory Date: Fri, 6 Aug 2021 22:21:29 -0400 Message-Id: <20210807022129.8842-1-npache@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: 945C070148EC Authentication-Results: imf27.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=MhZPj45b; dmarc=pass (policy=none) header.from=redhat.com; spf=none (imf27.hostedemail.com: domain of npache@redhat.com has no SPF policy when checking 170.10.133.124) smtp.mailfrom=npache@redhat.com X-Stat-Signature: 1ebimzz53ug56ari5eok65swfkaffxrq X-HE-Tag: 1628302909-136260 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Since commit b91ac374346b ("mm: vmscan: enforce inactive:active ratio at the reclaim root") swappiness can start prematurely swapping anon memory. This is due to the assumption that refaulting anon should always allow the shrinker to target anon memory. Add a check for swappiness being >0 before indiscriminately targeting Anon. This does not completely disable swapping, but rather tames the refaulting aspect of the code that allows for the deactivating of anon memory. A similar solution may be possible in the get_scan_count() part of the code, which determines the reclaim pressure for each LRU; however I believe that kind of solution may be too aggressive, and not allow other parts of the code (like direct reclaim) from targeting the active_anon list. This way we stop the problem at the heart of what is causing the issue, with the least amount of interference in other code paths. Furthermore, shrink_lruvec can modify the reclaim pressure of each LRU, which may make the get_scan_count solution even trickier. Changelog: -v2: made this mem_cgroup specific so now it will work with v1, v2, and no cgroups. I've also touched up my commit log. Signed-off-by: Nico Pache --- mm/vmscan.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index 4620df62f0ff..89d4e84011b7 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -2909,8 +2909,9 @@ static void shrink_node(pg_data_t *pgdat, struct scan_control *sc) refaults = lruvec_page_state(target_lruvec, WORKINGSET_ACTIVATE_ANON); - if (refaults != target_lruvec->refaults[0] || - inactive_is_low(target_lruvec, LRU_INACTIVE_ANON)) + if (mem_cgroup_swappiness(sc->target_mem_cgroup) && + (refaults != target_lruvec->refaults[0] || + inactive_is_low(target_lruvec, LRU_INACTIVE_ANON))) sc->may_deactivate |= DEACTIVATE_ANON; else sc->may_deactivate &= ~DEACTIVATE_ANON;