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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 68DFCC433EF for ; Wed, 2 Mar 2022 00:48:13 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id AC2E68D0002; Tue, 1 Mar 2022 19:48:12 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id A72B98D0001; Tue, 1 Mar 2022 19:48:12 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9616B8D0002; Tue, 1 Mar 2022 19:48:12 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay.hostedemail.com [64.99.140.26]) by kanga.kvack.org (Postfix) with ESMTP id 84E818D0001 for ; Tue, 1 Mar 2022 19:48:12 -0500 (EST) Received: from smtpin15.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id 49EE2243A6 for ; Wed, 2 Mar 2022 00:48:12 +0000 (UTC) X-FDA: 79197609624.15.6B02D54 Received: from mail-yw1-f173.google.com (mail-yw1-f173.google.com [209.85.128.173]) by imf30.hostedemail.com (Postfix) with ESMTP id CA37780003 for ; Wed, 2 Mar 2022 00:48:11 +0000 (UTC) Received: by mail-yw1-f173.google.com with SMTP id 00721157ae682-2db2add4516so626977b3.1 for ; Tue, 01 Mar 2022 16:48:11 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cloudflare.com; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=tGISSq+0/eqxa3jgdbDG1OBswttaVIadIYh/LsQ2juU=; b=SKmo/MIf+sHvmQP7Tq1jd8sBcQc82yVDekF/6BTZ6t/WS8pU8QklT9GlQI9BRYZklB KEAgBqjbkTCI9Rot27wjjSMoUBwiGMYt38sSmpZlvrGY8lY0q0wbqRUj4lZA38MkfMfa NG8M9MxV8c4bJ7MQqMuGEOphtmtQHahc5DdmE= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=tGISSq+0/eqxa3jgdbDG1OBswttaVIadIYh/LsQ2juU=; b=zaEIBeCxQcY9NAm8PQFvVdVzIwv2/Ae28YDNDUqJBnWl8S6T43VNuJN6R839PDsm9L vEBGjJ/i/aDTwryK6GVeIt2j2hOMXgxuqBPnUNR3SvcwrXNQpTBZk1XRFMUPXWQWMsGM yYifGQhygW+nAsFncS7ahemBVRuM78GtM/StNIx4rseR7nYyETfCj50DnSePYSZF1QrG YLldcC3ALXHvmXHj1GgfUKW2b+457wOX+PoKvCKRQvXTJpijNemM+L12x2a0DNei247Q RTUWKPViVwOJhASwIA3SzemfaRymQF1fwkB3lqTaFVerNm7JZ9wYMYVv/MbV9413Vzvn eEAw== X-Gm-Message-State: AOAM53257O4cb5b2IaXgStMQT93YttPJKNbYMxv6xSx6mlRTFUNuqDRk GggQc1/+WlYo10nqshbWhRC3DNLggVwUABHZZRWNWw== X-Google-Smtp-Source: ABdhPJyIcYAIR3g0JZ2jSMgJu9GR1FKrR43tA4UW/4Ezh7vO5GQoBIVCP+NqM0YRREnXk1hWxDNTd9FU7DyrhykQufc= X-Received: by 2002:a81:642:0:b0:2d6:baf8:ee52 with SMTP id 63-20020a810642000000b002d6baf8ee52mr27477417ywg.36.1646182091083; Tue, 01 Mar 2022 16:48:11 -0800 (PST) MIME-Version: 1.0 References: <20220224165838.oir5clpkkqpstpx3@google.com> <20220224185236.qgzm3jpoz2orjfcw@google.com> <20220225180345.GD12037@blackbody.suse.cz> <20220228230949.xrmy6j2glxsoffko@google.com> In-Reply-To: From: Ivan Babrou Date: Tue, 1 Mar 2022 16:48:00 -0800 Message-ID: Subject: Re: Regression in workingset_refault latency on 5.15 To: Shakeel Butt Cc: =?UTF-8?Q?Michal_Koutn=C3=BD?= , Daniel Dao , kernel-team , Linux MM , Johannes Weiner , Roman Gushchin , Feng Tang , Michal Hocko , Hillf Danton , Andrew Morton , Linus Torvalds Content-Type: text/plain; charset="UTF-8" X-Rspamd-Server: rspam10 X-Rspam-User: X-Stat-Signature: qtsdp7q79x13zrd9dteso9kz56ugn49a Authentication-Results: imf30.hostedemail.com; dkim=pass header.d=cloudflare.com header.s=google header.b="SKmo/MIf"; spf=none (imf30.hostedemail.com: domain of ivan@cloudflare.com has no SPF policy when checking 209.85.128.173) smtp.mailfrom=ivan@cloudflare.com; dmarc=pass (policy=reject) header.from=cloudflare.com X-Rspamd-Queue-Id: CA37780003 X-HE-Tag: 1646182091-826505 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: On Mon, Feb 28, 2022 at 3:34 PM Ivan Babrou wrote: > I scheduled some reboots for overnight, one machine in each group: > > 1. Control on 5.15.25 > 2. Your previous patch with delayed flush on top of 5.15.25 > 3. Your current patch with targeted flush on top of 5.15.25 > > Either Daniel or I should have some numbers tomorrow. Numbers for #2 (previous patch): $ sudo /usr/share/bcc/tools/funclatency -d 60 workingset_refault Tracing 1 functions for "workingset_refault"... Hit Ctrl-C to end. nsecs : count distribution 0 -> 1 : 0 | | 2 -> 3 : 0 | | 4 -> 7 : 0 | | 8 -> 15 : 0 | | 16 -> 31 : 0 | | 32 -> 63 : 0 | | 64 -> 127 : 0 | | 128 -> 255 : 0 | | 256 -> 511 : 27313 |****************************************| 512 -> 1023 : 11887 |***************** | 1024 -> 2047 : 3718 |***** | 2048 -> 4095 : 7095 |********** | 4096 -> 8191 : 11860 |***************** | 8192 -> 16383 : 4193 |****** | 16384 -> 32767 : 470 | | 32768 -> 65535 : 320 | | 65536 -> 131071 : 107 | | 131072 -> 262143 : 20 | | 262144 -> 524287 : 2 | | avg = 2929 nsecs, total: 196247510 nsecs, count: 66985 Numbers for #3 (the latest patch): $ sudo /usr/share/bcc/tools/funclatency -d 60 workingset_refault Tracing 1 functions for "workingset_refault"... Hit Ctrl-C to end. nsecs : count distribution 0 -> 1 : 0 | | 2 -> 3 : 0 | | 4 -> 7 : 0 | | 8 -> 15 : 0 | | 16 -> 31 : 0 | | 32 -> 63 : 0 | | 64 -> 127 : 0 | | 128 -> 255 : 0 | | 256 -> 511 : 6520 |****************************************| 512 -> 1023 : 3502 |********************* | 1024 -> 2047 : 726 |**** | 2048 -> 4095 : 2206 |************* | 4096 -> 8191 : 1078 |****** | 8192 -> 16383 : 70 | | 16384 -> 32767 : 39 | | 32768 -> 65535 : 28 | | 65536 -> 131071 : 8 | | 131072 -> 262143 : 1 | | 262144 -> 524287 : 11 | | 524288 -> 1048575 : 118 | | 1048576 -> 2097151 : 3722 |********************** | 2097152 -> 4194303 : 5854 |*********************************** | 4194304 -> 8388607 : 570 |*** | 8388608 -> 16777215 : 122 | | avg = 1100789 nsecs, total: 27051906434 nsecs, count: 24575 Looks like you were right that targeted flush is not going to be as good.