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 D7D29C001B5 for ; Fri, 2 Sep 2022 16:28:07 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 5D6E88D002C; Fri, 2 Sep 2022 12:28:07 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 586AD8D002B; Fri, 2 Sep 2022 12:28:07 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 4756B8D002C; Fri, 2 Sep 2022 12:28:07 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id 38ADF8D002B for ; Fri, 2 Sep 2022 12:28:07 -0400 (EDT) Received: from smtpin31.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id 0B0484115B for ; Fri, 2 Sep 2022 16:28:07 +0000 (UTC) X-FDA: 79867677414.31.8B93F3F Received: from mail-pj1-f47.google.com (mail-pj1-f47.google.com [209.85.216.47]) by imf30.hostedemail.com (Postfix) with ESMTP id C07D080078 for ; Fri, 2 Sep 2022 16:28:06 +0000 (UTC) Received: by mail-pj1-f47.google.com with SMTP id n65-20020a17090a5ac700b001fbb4fad865so2632933pji.1 for ; Fri, 02 Sep 2022 09:28:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date; bh=wNIc8ao3Yt5CIdYavjbANH3T4X5dkUReDekaysXGDSo=; b=QhH2Cm4lO6x1voUd1Dembk6oOd9z5VY5TRrL41iWRFmmpp8cdizG8V+OUu0UJk4T41 aBRwqxgqtgljwySCPWHW60HmpaQYfdGXRRn9TMfCgOZOrcLIYDmjjtbOslwy29nx+HB6 /3W7hEuGXsIJnNCIe2Zgw7XYDjOwT1N0H1P2AY4jkvJNMPcvwyHdV8NmdAEMgkPCaxFJ 2YOewm0AxPEacPvzTN5gOid4Eqo7tbyICfOHq715O4rt8jVMgZmaCTjZxCgWwYqIXacd TqSNDW+DbtXv484tEbqq+CuR4VMQFe7e/Zcvn9YWgp63KbN3gk41EGKm2NVZOZjgLss2 Ej5g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date; bh=wNIc8ao3Yt5CIdYavjbANH3T4X5dkUReDekaysXGDSo=; b=NYMOAqPsVzNiHcA6aPap2p3bl7PPYPHKdA3aEUOqASWsRxReftqYtQKO80srkvNL4w h3Vronoz1PF6WW4QSMka+topYKZlNjuMdPbELh6LJZaBMf+eMj7Xi+Wx+nLceqsaDsYS fLi/rY9waGheS4Ub7HKwD03EckdIFHT5EgvX2xXlsh9UZSILTN1o6jTVgIzaxxp19Tg4 nUTa5bT7BNnpgifehA627puZNuwfo1N+War0BjeviUU2KKrfDyas/WNmBGm60whnAM7H /dE+F9KUyAINoOd+VZPPnRk7Ghu2OM+avM7lLF9p7o2w/pZkf8GtlYzyUA0GBfgqvUxf lsnQ== X-Gm-Message-State: ACgBeo2AKJEaKwonDVYJ/ZcVbU8FKkDCycc2eqU/FgkSm7puPkvSwkGH KWeFxK1eBws7SgrTnYK8ZAInJ/AZQe1YbWefn2a/9g== X-Google-Smtp-Source: AA6agR5I57h1hhqBtwWvwWZ0317cT8zJVXYKMBQ5KfKg0bf77TfLd7MEyW9C3p5B1iCemxF/BozAyIVMm1z0nMDn7Vk= X-Received: by 2002:a17:902:b410:b0:172:c9d1:7501 with SMTP id x16-20020a170902b41000b00172c9d17501mr36380746plr.106.1662136085602; Fri, 02 Sep 2022 09:28:05 -0700 (PDT) MIME-Version: 1.0 References: <20220902152243.479592-1-jiebin.sun@intel.com> In-Reply-To: <20220902152243.479592-1-jiebin.sun@intel.com> From: Shakeel Butt Date: Fri, 2 Sep 2022 09:27:54 -0700 Message-ID: Subject: Re: [PATCH] ipc/msg.c: mitigate the lock contention with percpu counter To: Jiebin Sun Cc: Andrew Morton , vasily.averin@linux.dev, Dennis Zhou , Tejun Heo , Christoph Lameter , "Eric W. Biederman" , Alexey Gladkov , Manfred Spraul , alexander.mikhalitsyn@virtuozzo.com, Linux MM , LKML , "Chen, Tim C" , Feng Tang , Huang Ying , tianyou.li@intel.com, wangyang.guo@intel.com Content-Type: text/plain; charset="UTF-8" ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1662136086; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=wNIc8ao3Yt5CIdYavjbANH3T4X5dkUReDekaysXGDSo=; b=eeJZ1xvxml5WNioIajdLNToiiHLKNhhA+oz5FJ1E1naqF6PMAhUB40X9h6NDXHFyQxk231 Neb9hlk94pRJPzZOh+f48i1aYxHWrkJfyL+kQleEcqzeTc9Y2uta+GdVjP1/BRLSXH9K75 kcxuklhEeBsJ4P8Eg1CSw68aPEw8fPo= ARC-Authentication-Results: i=1; imf30.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b=QhH2Cm4l; spf=pass (imf30.hostedemail.com: domain of shakeelb@google.com designates 209.85.216.47 as permitted sender) smtp.mailfrom=shakeelb@google.com; dmarc=pass (policy=reject) header.from=google.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1662136086; a=rsa-sha256; cv=none; b=Tb7uYHQUNO7So2T/COyrw8nJ+By9bgb6OznE5RUQlp3cxnaeiSQ9N6pl5Lg1Q7r4w9q3lF v1A6mFqLP7ySh0IIGgGcZAU1D2/LoS7biOgGGer5NZ2LG7piZHryix8hLyrmjdisaobKaC YqoNYZdEs9btW7z8+hf3p5sVqzwy6VE= X-Stat-Signature: 5fg8r3epuufyntmzf15ikpta8e85kdu4 X-Rspamd-Queue-Id: C07D080078 Authentication-Results: imf30.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b=QhH2Cm4l; spf=pass (imf30.hostedemail.com: domain of shakeelb@google.com designates 209.85.216.47 as permitted sender) smtp.mailfrom=shakeelb@google.com; dmarc=pass (policy=reject) header.from=google.com X-Rspamd-Server: rspam05 X-Rspam-User: X-HE-Tag: 1662136086-467748 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 Fri, Sep 2, 2022 at 12:04 AM Jiebin Sun wrote: > > The msg_bytes and msg_hdrs atomic counters are frequently > updated when IPC msg queue is in heavy use, causing heavy > cache bounce and overhead. Change them to percpu_counters > greatly improve the performance. Since there is one unique > ipc namespace, additional memory cost is minimal. Reading > of the count done in msgctl call, which is infrequent. So > the need to sum up the counts in each CPU is infrequent. > > Apply the patch and test the pts/stress-ng-1.4.0 > -- system v message passing (160 threads). > > Score gain: 3.38x > > CPU: ICX 8380 x 2 sockets > Core number: 40 x 2 physical cores > Benchmark: pts/stress-ng-1.4.0 > -- system v message passing (160 threads) > > Signed-off-by: Jiebin Sun [...] > > +void percpu_counter_add_local(struct percpu_counter *fbc, s64 amount) > +{ > + this_cpu_add(*fbc->counters, amount); > +} > +EXPORT_SYMBOL(percpu_counter_add_local); Why not percpu_counter_add()? This may drift the fbc->count more than batch*nr_cpus. I am assuming that is not the issue for you as you always do an expensive sum in the slow path. As Andrew asked, this should be a separate patch.