From nobody Wed Dec 17 11:35:01 2025 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 4F6BDC4332F for ; Wed, 1 Nov 2023 10:29:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235131AbjKAK3G (ORCPT ); Wed, 1 Nov 2023 06:29:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44058 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235110AbjKAK3C (ORCPT ); Wed, 1 Nov 2023 06:29:02 -0400 Received: from mx1.sberdevices.ru (mx2.sberdevices.ru [45.89.224.132]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 88AA4DE; Wed, 1 Nov 2023 03:28:52 -0700 (PDT) Received: from p-infra-ksmg-sc-msk02 (localhost [127.0.0.1]) by mx1.sberdevices.ru (Postfix) with ESMTP id 39397120033; Wed, 1 Nov 2023 13:28:51 +0300 (MSK) DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.sberdevices.ru 39397120033 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=salutedevices.com; s=mail; t=1698834531; bh=pSKI4+L8HJRYn63UrrAYG4N/D56LntFTm89/ZK6IV24=; h=From:To:Subject:Date:Message-ID:MIME-Version:Content-Type:From; b=hQdEufFtltMp4tP59pfpQfMZAy5u5HUeSe7wslXZZYG0+RgoZAruI5nqoFqESnayv 8PDojzaOXskd/K7rXMwIx6qNKqm6R5vcNxDJK681HH83Rps5sg7ya2aMBELUJAJ6+k WMIv7jOTRVH3GHf7iukh+HewyvxYIkLSOb9Z4tjRH2k4Kp5IBR1TKZZ0fimlsP4pwF u4noMpFQRni0uYtGrP5RH1EpCivQAkmimxBRQzhD27R6S11XCbOzTNSmO9ePcwujmk QtHTqb1InR6V7SZErR2B8uCuSGeHYqP2v8FxvSROexv5DeZrnYOs7Ohb6iEczA7DlU slqJr1B6XRbag== Received: from p-i-exch-sc-m01.sberdevices.ru (p-i-exch-sc-m01.sberdevices.ru [172.16.192.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.sberdevices.ru (Postfix) with ESMTPS; Wed, 1 Nov 2023 13:28:50 +0300 (MSK) Received: from localhost.localdomain (100.64.160.123) by p-i-exch-sc-m01.sberdevices.ru (172.16.192.107) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1118.37; Wed, 1 Nov 2023 13:28:50 +0300 From: Dmitry Rokosov To: , , , , , , , CC: , , , , , , Dmitry Rokosov Subject: [PATCH v1 2/2] mm: memcg: introduce new event to trace shrink_memcg Date: Wed, 1 Nov 2023 13:28:37 +0300 Message-ID: <20231101102837.25205-3-ddrokosov@salutedevices.com> X-Mailer: git-send-email 2.36.0 In-Reply-To: <20231101102837.25205-1-ddrokosov@salutedevices.com> References: <20231101102837.25205-1-ddrokosov@salutedevices.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Originating-IP: [100.64.160.123] X-ClientProxiedBy: p-i-exch-sc-m01.sberdevices.ru (172.16.192.107) To p-i-exch-sc-m01.sberdevices.ru (172.16.192.107) X-KSMG-Rule-ID: 10 X-KSMG-Message-Action: clean X-KSMG-AntiSpam-Lua-Profiles: 181040 [Nov 01 2023] X-KSMG-AntiSpam-Version: 6.0.0.2 X-KSMG-AntiSpam-Envelope-From: ddrokosov@salutedevices.com X-KSMG-AntiSpam-Rate: 0 X-KSMG-AntiSpam-Status: not_detected X-KSMG-AntiSpam-Method: none X-KSMG-AntiSpam-Auth: dkim=none X-KSMG-AntiSpam-Info: LuaCore: 543 543 1e3516af5cdd92079dfeb0e292c8747a62cb1ee4, {Tracking_from_domain_doesnt_match_to}, 100.64.160.123:7.1.2;p-i-exch-sc-m01.sberdevices.ru:7.1.1,5.0.1;d41d8cd98f00b204e9800998ecf8427e.com:7.1.1;127.0.0.199:7.1.2;salutedevices.com:7.1.1, FromAlignment: s, ApMailHostAddress: 100.64.160.123 X-MS-Exchange-Organization-SCL: -1 X-KSMG-AntiSpam-Interceptor-Info: scan successful X-KSMG-AntiPhishing: Clean X-KSMG-LinksScanning: Clean X-KSMG-AntiVirus: Kaspersky Secure Mail Gateway, version 2.0.1.6960, bases: 2023/11/01 06:18:00 #22376334 X-KSMG-AntiVirus-Status: Clean, skipped Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" The shrink_memcg flow plays a crucial role in memcg reclamation. Currently, it is not possible to trace this point from non-direct reclaim paths. However, direct reclaim has its own tracepoint, so there is no issue there. In certain cases, when debugging memcg pressure, developers may need to identify all potential requests for memcg reclamation including kswapd(). The patchset introduces the tracepoints mm_vmscan_memcg_shrink_{begin|end}() to address this problem. Example of output in the kswapd context (non-direct reclaim): kswapd0-39 [001] ..... 240.356378: mm_vmscan_memcg_shrink_begin:= memcg=3Dtest order=3D0 gfp_flags=3DGFP_KERNEL kswapd0-39 [001] ..... 240.356396: mm_vmscan_memcg_shrink_end: m= emcg=3Dtest nr_reclaimed=3D0 kswapd0-39 [001] ..... 240.356420: mm_vmscan_memcg_shrink_begin:= memcg=3Dtest oorder=3D0 gfp_flags=3DGFP_KERNEL kswapd0-39 [001] ..... 240.356454: mm_vmscan_memcg_shrink_end: m= emcg=3Dtest nr_reclaimed=3D1 kswapd0-39 [001] ..... 240.356479: mm_vmscan_memcg_shrink_begin:= memcg=3Dtest oorder=3D0 gfp_flags=3DGFP_KERNEL kswapd0-39 [001] ..... 240.356506: mm_vmscan_memcg_shrink_end: m= emcg=3Dtest nr_reclaimed=3D4 kswapd0-39 [001] ..... 240.356525: mm_vmscan_memcg_shrink_begin:= memcg=3Dtest oorder=3D0 gfp_flags=3DGFP_KERNEL kswapd0-39 [001] ..... 240.356593: mm_vmscan_memcg_shrink_end: m= emcg=3Dtest nr_reclaimed=3D11 kswapd0-39 [001] ..... 240.356614: mm_vmscan_memcg_shrink_begin:= memcg=3Dtest oorder=3D0 gfp_flags=3DGFP_KERNEL kswapd0-39 [001] ..... 240.356738: mm_vmscan_memcg_shrink_end: m= emcg=3Dtest nr_reclaimed=3D25 kswapd0-39 [001] ..... 240.356790: mm_vmscan_memcg_shrink_begin:= memcg=3Dtest oorder=3D0 gfp_flags=3DGFP_KERNEL kswapd0-39 [001] ..... 240.357125: mm_vmscan_memcg_shrink_end: m= emcg=3Dtest nr_reclaimed=3D53 Signed-off-by: Dmitry Rokosov --- include/trace/events/vmscan.h | 14 ++++++++++++++ mm/vmscan.c | 7 +++++++ 2 files changed, 21 insertions(+) diff --git a/include/trace/events/vmscan.h b/include/trace/events/vmscan.h index 124bc22866c8..518e7232c9eb 100644 --- a/include/trace/events/vmscan.h +++ b/include/trace/events/vmscan.h @@ -182,6 +182,13 @@ DEFINE_EVENT(mm_vmscan_memcg_reclaim_begin_template, m= m_vmscan_memcg_softlimit_r TP_ARGS(memcg, order, gfp_flags) ); =20 +DEFINE_EVENT(mm_vmscan_memcg_reclaim_begin_template, mm_vmscan_memcg_shrin= k_begin, + + TP_PROTO(const struct mem_cgroup *memcg, int order, gfp_t gfp_flags), + + TP_ARGS(memcg, order, gfp_flags) +); + #endif /* CONFIG_MEMCG */ =20 DECLARE_EVENT_CLASS(mm_vmscan_direct_reclaim_end_template, @@ -247,6 +254,13 @@ DEFINE_EVENT(mm_vmscan_memcg_reclaim_end_template, mm_= vmscan_memcg_softlimit_rec TP_ARGS(memcg, nr_reclaimed) ); =20 +DEFINE_EVENT(mm_vmscan_memcg_reclaim_end_template, mm_vmscan_memcg_shrink_= end, + + TP_PROTO(const struct mem_cgroup *memcg, unsigned long nr_reclaimed), + + TP_ARGS(memcg, nr_reclaimed) +); + #endif /* CONFIG_MEMCG */ =20 TRACE_EVENT(mm_shrink_slab_start, diff --git a/mm/vmscan.c b/mm/vmscan.c index 4309eaf188b4..6b9619922dfb 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -6461,6 +6461,10 @@ static void shrink_node_memcgs(pg_data_t *pgdat, str= uct scan_control *sc) */ cond_resched(); =20 + trace_mm_vmscan_memcg_shrink_begin(memcg, + sc->order, + sc->gfp_mask); + mem_cgroup_calculate_protection(target_memcg, memcg); =20 if (mem_cgroup_below_min(target_memcg, memcg)) { @@ -6491,6 +6495,9 @@ static void shrink_node_memcgs(pg_data_t *pgdat, stru= ct scan_control *sc) shrink_slab(sc->gfp_mask, pgdat->node_id, memcg, sc->priority); =20 + trace_mm_vmscan_memcg_shrink_end(memcg, + sc->nr_reclaimed - reclaimed); + /* Record the group's reclaim efficiency */ if (!sc->proactive) vmpressure(sc->gfp_mask, memcg, false, --=20 2.25.1