From patchwork Thu Feb 2 23:32:29 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yosry Ahmed X-Patchwork-Id: 13126809 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 20CF7C636D7 for ; Thu, 2 Feb 2023 23:32:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233251AbjBBXcj (ORCPT ); Thu, 2 Feb 2023 18:32:39 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50720 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233244AbjBBXci (ORCPT ); Thu, 2 Feb 2023 18:32:38 -0500 Received: from mail-pf1-x449.google.com (mail-pf1-x449.google.com [IPv6:2607:f8b0:4864:20::449]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AE844183 for ; Thu, 2 Feb 2023 15:32:37 -0800 (PST) Received: by mail-pf1-x449.google.com with SMTP id k14-20020aa7972e000000b00593a8232ac3so1683074pfg.22 for ; Thu, 02 Feb 2023 15:32:37 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=0NNiCqwzESyAJCUAtzOveFlWcEoCPQvaoYU5oWya4UE=; b=hOhCADwPkxUGmi7V1P/nnFPjlarle5tUS/LLXkpE2OMQZSESuPz1Yg7ch5+w2lQPvZ Tg/E8g4ve+TuLwEeRfChTbEYbLJeSDJDBhmLL+z83Q3UbkFRR/7iALI3n//9YzuETtUk /td2TUtQtadczPSW8P9uXTi/L7bXWxzWMSBHRmqrt9SBSEfcBH/jtfBlcjWv7c1f+PLe QQJMnYWOv7ywl4B7eaZ7s3dALT60pveMbI3kcs7UOtDp14gKlyebUk9ejlg7acW+153Z oPfBCDEgRhQOIX+ZejkUx9YYjTBJC43e4lfmtvzzmccRB1Rl0AHErHGP8WlCALz8YStS jSAw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=0NNiCqwzESyAJCUAtzOveFlWcEoCPQvaoYU5oWya4UE=; b=uzxJv4rs5zI4v8qaxBXrz133CGOEw4hgWPG4qoKF37LkP6mjofqq+NnCjlxOKhmWf+ FpavC+KAsrQD65HFKBNP7XF2axKZFWTAbAxTjoUnQcDl2eIlqeb/6z1hvRobyxHk8+NO 2cfXx//nwKvAetUPlbpGy3Av5xrm5fL1XT7XeLLWgmETroMg9ziTfJG8yFLZ3wvofx0x ef7CKrFVtr6UOGJsw51SRHdLPxb/tPPLleXToMwgS7kfLv/NMkJiipECJWXGzbGTJwY+ 2OYgkQEbbjQxQCqz/czLCDLxSGkrgG5JeiGmW04Ua6qZFF/oa/9AtZ2gBzETP/drGFdr Y2iA== X-Gm-Message-State: AO0yUKXQL4kbGTvW8qMTzux2FJZ0ctv0aFW3DCtM5XisHyPtZJPRYG5u 24QlYrJeidovgbUrloTvrcpTIdmubQRe1V97 X-Google-Smtp-Source: AK7set/gX+d7qL2VYRm0mNT1mURMK3jqpTnNExhfErr1wouO0vmd1XoXrrDp0BwbdxbCN+7oo8RXZwzOeOx6nPe4 X-Received: from yosry.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:2327]) (user=yosryahmed job=sendgmr) by 2002:a17:903:1c8:b0:193:9ec:fc13 with SMTP id e8-20020a17090301c800b0019309ecfc13mr1942596plh.33.1675380757137; Thu, 02 Feb 2023 15:32:37 -0800 (PST) Date: Thu, 2 Feb 2023 23:32:29 +0000 In-Reply-To: <20230202233229.3895713-1-yosryahmed@google.com> Mime-Version: 1.0 References: <20230202233229.3895713-1-yosryahmed@google.com> X-Mailer: git-send-email 2.39.1.519.gcb327c4b5f-goog Message-ID: <20230202233229.3895713-3-yosryahmed@google.com> Subject: [RFC PATCH v1 2/2] mm: vmscan: ignore non-LRU-based reclaim in memcg reclaim From: Yosry Ahmed To: Alexander Viro , "Darrick J. Wong" , Christoph Lameter , David Rientjes , Joonsoo Kim , Vlastimil Babka , Roman Gushchin , Hyeonggon Yoo <42.hyeyoo@gmail.com>, "Matthew Wilcox (Oracle)" , Miaohe Lin , David Hildenbrand , Johannes Weiner , Peter Xu , NeilBrown , Shakeel Butt , Michal Hocko Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-xfs@vger.kernel.org, linux-mm@kvack.org, Yosry Ahmed Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org We keep track of different types of reclaimed pages through reclaim_state->reclaimed, and we add them to the reported number of reclaimed pages. For non-memcg reclaim, this makes sense. For memcg reclaim, we have no clue if those pages are charged to the memcg under reclaim. Slab pages are shared by different memcgs, so a freed slab page may have only been partially charged to the memcg under reclaim. The same goes for clean file pages from pruned inodes or xfs buffer pages, there is no way to link them to the memcg under reclaim. Stop reporting those freed pages as reclaimed pages during memcg reclaim. This should make the return value of writing to memory.reclaim, and may help reduce unnecessary reclaim retries during memcg charging. Generally, this should make the return value of try_to_free_mem_cgroup_pages() more accurate. In some limited cases (e.g. freed a slab page that was mostly charged to the memcg under reclaim), the return value of try_to_free_mem_cgroup_pages() can be underestimated, but this should be fine as it is mostly called in a retry loop. Signed-off-by: Yosry Ahmed --- mm/vmscan.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index 63a27d2f6f31..207998b16e5f 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -6181,7 +6181,7 @@ static void shrink_node(pg_data_t *pgdat, struct scan_control *sc) shrink_node_memcgs(pgdat, sc); - if (reclaim_state) { + if (reclaim_state && !cgroup_reclaim(sc)) { sc->nr_reclaimed += reclaim_state->reclaimed; reclaim_state->reclaimed = 0; }