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 6544AC433EF for ; Wed, 2 Mar 2022 22:33:55 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 862F98D0002; Wed, 2 Mar 2022 17:33:54 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 811E08D0001; Wed, 2 Mar 2022 17:33:54 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 6DB4F8D0002; Wed, 2 Mar 2022 17:33:54 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0043.hostedemail.com [216.40.44.43]) by kanga.kvack.org (Postfix) with ESMTP id 5FACF8D0001 for ; Wed, 2 Mar 2022 17:33:54 -0500 (EST) Received: from smtpin21.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 233211808F18E for ; Wed, 2 Mar 2022 22:33:54 +0000 (UTC) X-FDA: 79200899988.21.F5585E5 Received: from mail-yw1-f180.google.com (mail-yw1-f180.google.com [209.85.128.180]) by imf27.hostedemail.com (Postfix) with ESMTP id B5C7B40002 for ; Wed, 2 Mar 2022 22:33:52 +0000 (UTC) Received: by mail-yw1-f180.google.com with SMTP id 00721157ae682-2dbd97f9bfcso35387237b3.9 for ; Wed, 02 Mar 2022 14:33:52 -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=znD4jbaedsn7RVa/mECjAsClKXFzT10ek3BkOxRinkQ=; b=rU3ZWR8c3dDo62xWKRX47eJv9Ysv8L4hDHC1zpeUQzuRgdylqvw3IAosS9JQnVaWr1 aXUbJxFp81WkALzi15wudyfDvMyp/7W731GySNww1APt/uYxgFU31JvfnFCYHRIJOUto 2KoscRI1gdGpl6ZevAHEUaMdUxeSkZy7qsH10= 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=znD4jbaedsn7RVa/mECjAsClKXFzT10ek3BkOxRinkQ=; b=XQzNTlPaJU0Pm5VaFp869whlPnYuAkMCFHKfKwo+EodAbro+TbwUIYUTGWeMH6ltdc wguelAuuhXmqjrB9LtSs0LkrqMLLuvoMLqfx1xihL7kbQlJ2BANXPvVdxyslbLpkIwrE a0hD+a1Tlc1bcCojrHY6Pt9/PgVEOasMvQolfPqY3JpzV64OG6m28sa8BPTi0ohGAysm RRxnqyv7BpBDnmTQXLBdInYUw0MDSzsut+e8Q7MtnqJCCR/dpBcX6oioP3wmTEU7HtJD ct7InJl+FUGk7ghiSIG1K7aTD2fX4O/Uip3To+QezZ7SI5llWzx5eHlPUHT6AU6y9xnc qE3g== X-Gm-Message-State: AOAM530HuhUttwUjoqAtIVZ1mL/7fi3w0xIgNdDYHTiOFPyoqlmiMVwC b/lZHFFMqKRSQpa/TyvXQSi4ptq7ebZPuqqx2rPIwA== X-Google-Smtp-Source: ABdhPJyAwOwddLrjrWLfoViTc5LI157FwxkKXafDVFik973BNWSVKR3RD7i2PmUd3ZpJZ9ELVzGIrqW8qnaeWVeYtAc= X-Received: by 2002:a0d:d687:0:b0:2d6:9079:9595 with SMTP id y129-20020a0dd687000000b002d690799595mr33140245ywd.32.1646260431841; Wed, 02 Mar 2022 14:33:51 -0800 (PST) MIME-Version: 1.0 References: <20220224185236.qgzm3jpoz2orjfcw@google.com> <20220225180345.GD12037@blackbody.suse.cz> <20220228230949.xrmy6j2glxsoffko@google.com> <20220302025022.nnmpwxmkqed2icck@google.com> In-Reply-To: From: Ivan Babrou Date: Wed, 2 Mar 2022 14:33:41 -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-Rspam-User: X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: B5C7B40002 X-Stat-Signature: nb69xjc69do59tubxe6prky6e6s3ouod Authentication-Results: imf27.hostedemail.com; dkim=pass header.d=cloudflare.com header.s=google header.b=rU3ZWR8c; spf=none (imf27.hostedemail.com: domain of ivan@cloudflare.com has no SPF policy when checking 209.85.128.180) smtp.mailfrom=ivan@cloudflare.com; dmarc=pass (policy=reject) header.from=cloudflare.com X-HE-Tag: 1646260432-148222 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 Tue, Mar 1, 2022 at 7:40 PM Ivan Babrou wrote: > > On Tue, Mar 1, 2022 at 6:50 PM Shakeel Butt wrote: > > > > On Tue, Mar 01, 2022 at 04:48:00PM -0800, Ivan Babrou wrote: > > > > [...] > > > > > Looks like you were right that targeted flush is not going to be as good. > > > > > > Thanks a lot. Can you please try the following patch (independent of other > > patches) as well? > > Sure thing, I'll come back with the numbers tomorrow. Measurements from different configurations: * Baseline 5.15.25: $ 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 : 15931 |****************************************| 512 -> 1023 : 7040 |***************** | 1024 -> 2047 : 1566 |*** | 2048 -> 4095 : 3844 |********* | 4096 -> 8191 : 1689 |**** | 8192 -> 16383 : 115 | | 16384 -> 32767 : 54 | | 32768 -> 65535 : 42 | | 65536 -> 131071 : 14 | | 131072 -> 262143 : 4 | | 262144 -> 524287 : 4 | | 524288 -> 1048575 : 92 | | 1048576 -> 2097151 : 2322 |***** | 2097152 -> 4194303 : 8244 |******************** | 4194304 -> 8388607 : 775 |* | 8388608 -> 16777215 : 73 | | avg = 776487 nsecs, total: 32464181849 nsecs, count: 41809 * Delayed flush: $ 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 : 16271 |****************************************| 512 -> 1023 : 8147 |******************** | 1024 -> 2047 : 2743 |****** | 2048 -> 4095 : 3964 |********* | 4096 -> 8191 : 7137 |***************** | 8192 -> 16383 : 4039 |********* | 16384 -> 32767 : 352 | | 32768 -> 65535 : 214 | | 65536 -> 131071 : 80 | | 131072 -> 262143 : 15 | | 262144 -> 524287 : 0 | | 524288 -> 1048575 : 1 | | avg = 3248 nsecs, total: 139586555 nsecs, count: 42963 * Targeted flush: $ 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 : 25298 |****************************************| 512 -> 1023 : 13334 |********************* | 1024 -> 2047 : 1519 |** | 2048 -> 4095 : 4265 |****** | 4096 -> 8191 : 2339 |*** | 8192 -> 16383 : 162 | | 16384 -> 32767 : 73 | | 32768 -> 65535 : 70 | | 65536 -> 131071 : 23 | | 131072 -> 262143 : 1 | | 262144 -> 524287 : 3 | | 524288 -> 1048575 : 55 | | 1048576 -> 2097151 : 1409 |** | 2097152 -> 4194303 : 8306 |************* | 4194304 -> 8388607 : 1139 |* | 8388608 -> 16777215 : 89 | | avg = 589361 nsecs, total: 34233041412 nsecs, count: 5808 * Your most recent 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 : 37051 |****************************************| 512 -> 1023 : 17144 |****************** | 1024 -> 2047 : 1051 |* | 2048 -> 4095 : 2705 |** | 4096 -> 8191 : 1911 |** | 8192 -> 16383 : 184 | | 16384 -> 32767 : 93 | | 32768 -> 65535 : 70 | | 65536 -> 131071 : 30 | | 131072 -> 262143 : 21 | | 262144 -> 524287 : 216 | | 524288 -> 1048575 : 1100 |* | 1048576 -> 2097151 : 6522 |******* | 2097152 -> 4194303 : 5903 |****** | 4194304 -> 8388607 : 467 | | 8388608 -> 16777215 : 19 | | avg = 403261 nsecs, total: 30037729036 nsecs, count: 74487 Looks like there are plenty of longer pauses still. I can also get the numbers from 5.10 for you if you want.