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 8EEDBC32774 for ; Thu, 25 Aug 2022 15:24:17 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id C87466B0074; Thu, 25 Aug 2022 11:24:16 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id C359D940008; Thu, 25 Aug 2022 11:24:16 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id AFD7B940007; Thu, 25 Aug 2022 11:24:16 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id A1F836B0074 for ; Thu, 25 Aug 2022 11:24:16 -0400 (EDT) Received: from smtpin19.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 691A9AC7C6 for ; Thu, 25 Aug 2022 15:24:16 +0000 (UTC) X-FDA: 79838486112.19.1B0EF95 Received: from mail-pl1-f181.google.com (mail-pl1-f181.google.com [209.85.214.181]) by imf17.hostedemail.com (Postfix) with ESMTP id 24ED440002 for ; Thu, 25 Aug 2022 15:24:15 +0000 (UTC) Received: by mail-pl1-f181.google.com with SMTP id p18so18804532plr.8 for ; Thu, 25 Aug 2022 08:24:15 -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; bh=Sjxu1KZYU3KDG78+cZAn5+zrZMruhm46V6F/elCTC6I=; b=cgdSCg/G5MIqnMdtGF27PjSCoHoxA2BsgT02jo7Ty55H5CD+J3M0vHpW6lHr8NcHWU X4d85j0jzRSVoQQ1MCpo3IQxt2FbpJcglk7ukGEyRJIhQszVQ9wx2i35z97DqqSPd8oC VCP76agWwaX+4eMZ+QIx3J3v9Nver8Y2hT/qeJt1TMaAprapOxqq9WUzYpSdGmHshkAY GfaP+h3+0CtF8cAYQQM3KgFAd8WHhKHivvxwKgX45zfRGdSEJ/wxeU6tfT/4yjg6gHiJ kPNYCejF6P/dRAtVBxvPeyL9+3p/YImkl2YVTcNEsoYooOr0nt/CrL9psmY7f6J0bNqd Y+dw== 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; bh=Sjxu1KZYU3KDG78+cZAn5+zrZMruhm46V6F/elCTC6I=; b=yGbwguVQqs2kBOKjOgKHE/NUbBoETHyjO1zn2sj1W3+QM8OuNX+9iDlNQfD03+prYO Q9qWGpY18yK+uurKksAwwBxNNNX908Raexml5A5vFvIp2RvUxRBtIHb1HYm/aDsn1JOw XatKuc/rnRTj/hbXPXZ7YEN2vX02jLwTWButFOt0jrd0xfEqnUFKrTDBG9h5CAvQ0lJZ 7HdR8mp3uiaW7ad1vd4Tr5UPBGgvaZQHb48SNTVxsWXHnpcnSiVRYZqRHlf/muM05j6Q dUBzP20eRSK2c9XomOZAItTEmN5OgB1gmOmxFRwuJkeVlV/TKt5KfixwGfyX9LLUU22J P9gg== X-Gm-Message-State: ACgBeo0lSz8/hEbsRb5lwpVn8U4Jp3VCXXUAaMYl2K2pOVNzUfKLkpG3 yXWeBNY3pWafmmOWAZkxo/GsQxLRQDKQD1Z6HJvITg== X-Google-Smtp-Source: AA6agR47CCHMXIXPEnmUh5MEwo8eqnV5OkxhX40/DKDSoDxPq9qnYdSc5lDaOytVRTphX+pidszh2naGv0wE7nfCZh8= X-Received: by 2002:a17:90b:1d91:b0:1fb:4f7f:852e with SMTP id pf17-20020a17090b1d9100b001fb4f7f852emr14163491pjb.126.1661441054986; Thu, 25 Aug 2022 08:24:14 -0700 (PDT) MIME-Version: 1.0 References: <20220825000506.239406-1-shakeelb@google.com> <20220825000506.239406-3-shakeelb@google.com> <20220824173330.2a15bcda24d2c3c248bc43c7@linux-foundation.org> <20220824222150.61c516a83bfe0ecb6c9b5348@linux-foundation.org> In-Reply-To: <20220824222150.61c516a83bfe0ecb6c9b5348@linux-foundation.org> From: Shakeel Butt Date: Thu, 25 Aug 2022 08:24:02 -0700 Message-ID: Subject: Re: [PATCH v2 2/3] mm: page_counter: rearrange struct page_counter fields To: Andrew Morton Cc: Johannes Weiner , Michal Hocko , Roman Gushchin , Muchun Song , =?UTF-8?Q?Michal_Koutn=C3=BD?= , Eric Dumazet , Soheil Hassas Yeganeh , Feng Tang , Oliver Sang , lkp@lists.01.org, Cgroups , Linux MM , netdev , LKML Content-Type: text/plain; charset="UTF-8" ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1661441056; a=rsa-sha256; cv=none; b=FzCWNfeSsYW71d+BlYAAQ+w1ULAUDJRJWXEQJgcy9vgqnwz+LhAwD9EFBU7wE8U5a8CCuN 3cR0P6FQycMQzn8yG2DX/xrY9C3tcJsMkIHKoAoPEpdSdWo7mennUuoChAaDZhFUi4XApg HgnCKAZ9snCMCoqZGkVZ4hbeYIBJjvE= ARC-Authentication-Results: i=1; imf17.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b="cgdSCg/G"; spf=pass (imf17.hostedemail.com: domain of shakeelb@google.com designates 209.85.214.181 as permitted sender) smtp.mailfrom=shakeelb@google.com; dmarc=pass (policy=reject) header.from=google.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1661441056; 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=Sjxu1KZYU3KDG78+cZAn5+zrZMruhm46V6F/elCTC6I=; b=IJCh9rtMioU/NqrN8Y7g2ylF6hxIah24X9U08OrLxSpwdTtx6jAfhYdiMiIFTHMbwdBJe9 YRJRWkPJpdjDP9mh9cg2ZI8YKujmxsSp/vKOBe5U1xkxqoD6bTr+Uo+dnsj50e2CK8PNqf g21s8gpKMWVLugJtlAnsCB53AxE7i3k= X-Stat-Signature: stf3dqziaay41rcfzhwgfz3xfbo81zhm X-Rspamd-Queue-Id: 24ED440002 X-Rspam-User: X-Rspamd-Server: rspam06 Authentication-Results: imf17.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b="cgdSCg/G"; spf=pass (imf17.hostedemail.com: domain of shakeelb@google.com designates 209.85.214.181 as permitted sender) smtp.mailfrom=shakeelb@google.com; dmarc=pass (policy=reject) header.from=google.com X-HE-Tag: 1661441055-257777 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 Wed, Aug 24, 2022 at 10:21 PM Andrew Morton wrote: > > On Wed, 24 Aug 2022 21:41:42 -0700 Shakeel Butt wrote: > > > > Did you evaluate the effects of using a per-cpu counter of some form? > > > > Do you mean per-cpu counter for usage or something else? > > percpu_counter, perhaps. Or some hand-rolled thing if that's more suitable. > > > The usage > > needs to be compared against the limits and accumulating per-cpu is > > costly particularly on larger machines, > > Well, there are tricks one can play. For example, only run > __percpu_counter_sum() when `usage' is close to its limit. > > I'd suggest flinging together a prototype which simply uses > percpu_counter_read() all the time. If the performance testing results > are sufficiently promising, then look into the accuracy issues. > Thanks, I will take a stab at that in a week or so.