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 52450C35274 for ; Tue, 19 Dec 2023 00:44:53 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 5F4BB6B0075; Mon, 18 Dec 2023 19:44:52 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 57DFC6B0078; Mon, 18 Dec 2023 19:44:52 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 41DFE6B007B; Mon, 18 Dec 2023 19:44:52 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 2A5E26B0075 for ; Mon, 18 Dec 2023 19:44:52 -0500 (EST) Received: from smtpin10.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id 25F38A0256 for ; Tue, 19 Dec 2023 00:44:51 +0000 (UTC) X-FDA: 81581722782.10.F0CF697 Received: from mail-qt1-f173.google.com (mail-qt1-f173.google.com [209.85.160.173]) by imf28.hostedemail.com (Postfix) with ESMTP id 58B80C001A for ; Tue, 19 Dec 2023 00:44:49 +0000 (UTC) Authentication-Results: imf28.hostedemail.com; dkim=pass header.d=gmail.com header.s=20230601 header.b=d85Iw8tW; spf=pass (imf28.hostedemail.com: domain of haokexin@gmail.com designates 209.85.160.173 as permitted sender) smtp.mailfrom=haokexin@gmail.com; dmarc=pass (policy=none) header.from=gmail.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1702946689; 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=c3GeSvwQOB2zjQSDPX1eFOBQvIByQyo6Yt4snLk9mKg=; b=7XLPRweJbWwX+Y7jQ02KrC4tLh6NiaAtXFbp6FtAoy9+mGGmMdYd6trq1si7CIfkna3lhA 3PBbNy0rJjzlZ12ZKXFuVdaq9mUcgybX/cD1UrsE6oreT9zuypMVKSWpiXuaysudVbvm/H EhWhTOtX5Yxq4Pr0g0Ep7WNaTQVC3SU= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1702946689; a=rsa-sha256; cv=none; b=muL69yBhuJ4u5d/Qz34l6ewhrhu9G93Uyz6r6i8boVBaUpVO5IQ7Rhk/4WDa9m3KWAQmeN iJf1v2sSxFR3XCNtkLd3+a3MBvfKQ7NWuNiIwsum1B8fkth3sfGYOAWTL1lhx7hNdhNprz bUMeKvxFVt0r7Uj0B1LjnwGme+4dET0= ARC-Authentication-Results: i=1; imf28.hostedemail.com; dkim=pass header.d=gmail.com header.s=20230601 header.b=d85Iw8tW; spf=pass (imf28.hostedemail.com: domain of haokexin@gmail.com designates 209.85.160.173 as permitted sender) smtp.mailfrom=haokexin@gmail.com; dmarc=pass (policy=none) header.from=gmail.com Received: by mail-qt1-f173.google.com with SMTP id d75a77b69052e-425f5964ce1so34930341cf.1 for ; Mon, 18 Dec 2023 16:44:49 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1702946688; x=1703551488; darn=kvack.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=c3GeSvwQOB2zjQSDPX1eFOBQvIByQyo6Yt4snLk9mKg=; b=d85Iw8tWU0p46B81nFbTTyrwI4KlEXmgp6wmWfWRcrWB6G/FGWc55nFTwnsugn8LBN aVI8kJfJ3G2C9jjijvjlwDpJSqcaKM5UzrVbhXunrPOwQJEHkiR1rzJwnkAOdFQbPTno xuZ1u0cEk7Pb9hTLUFgxLR0v7T72ToZgXVXKtFb/hmLjvxrPebyKiK84etyVyNbwCsdq tFkedag1U8RtMsg+s9h4Ox3UY7r8XICFxp/CFkoMQUvBAe2xOOUclACN3gCQhR/BKw1O Ogy3hN21NhA/zZC7k4VgAKKMVdae3X5FWZ3B7pM3TbSoWJmpA1vs1wlVHyBgOJq0x26x dZPg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1702946688; x=1703551488; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=c3GeSvwQOB2zjQSDPX1eFOBQvIByQyo6Yt4snLk9mKg=; b=jXRZudRCDl7fKb3eAZwlVnojiNBoIrxbBDnRHLgGXseJjaQd33RAgrK1688D4ycHJZ DervR3EqAmnDXdSa8rkzTCxDLt7PipZuMZQe/4JlWoaGiTV8tMEYWrNwHzrBAC4wSsqk uce+t72le3oCR3M3TQPtnePTA3L+nOOFogXKn+7qn0Y9fhEv6jchZpzqnNfdNyjSE0iL /mgQJIH3ZR+4IuAmzoF4uLTb+qUFUxpKmuD9Q35NmZHPGdltqIQI2e3BFAX533Ir/I7X zMwXjb9D7DN6S/5wxMNK42leHzVwv4K3NB45fN3w2AIYQKcki82Svn6jhnbhK378r7El s28A== X-Gm-Message-State: AOJu0Yzus9XVTtRh2d8ikWBJ/dmo49DryPS9jlr3hLO+kykT6wlrkgH7 mxPGOyJbAHrV7h3ZsDCWKRw= X-Google-Smtp-Source: AGHT+IGIU0O/c8x4aZgeIEHUEFbu65swXmCFgftGkMv/6dsu0zw42yEZehnScdYAmUDO1XKNK1KfYg== X-Received: by 2002:ac8:5bce:0:b0:425:4043:50f5 with SMTP id b14-20020ac85bce000000b00425404350f5mr24484947qtb.132.1702946688356; Mon, 18 Dec 2023 16:44:48 -0800 (PST) Received: from pek-khao-d3 (unknown-105-121.windriver.com. [147.11.105.121]) by smtp.gmail.com with ESMTPSA id p8-20020a05620a22e800b0077f289b92c6sm8742902qki.123.2023.12.18.16.44.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 18 Dec 2023 16:44:47 -0800 (PST) Date: Tue, 19 Dec 2023 08:44:42 +0800 From: Kevin Hao To: Andrew Morton Cc: linux-mm@kvack.org, "Rafael J. Wysocki" , Pavel Machek Subject: Re: [PATCH] mm/khugepaged: Remove unnecessary try_to_freeze() Message-ID: References: <20231216114341.2281852-1-haokexin@gmail.com> <20231218103451.fd11a2179a01d622cea01858@linux-foundation.org> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="ybhwcA8vJ+NWw6Ag" Content-Disposition: inline In-Reply-To: <20231218103451.fd11a2179a01d622cea01858@linux-foundation.org> X-Stat-Signature: ah84rtizewrfaydozyype9bnmmf63gid X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: 58B80C001A X-Rspam-User: X-HE-Tag: 1702946689-91643 X-HE-Meta: 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 /GdhtX/+ 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 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: List-Subscribe: List-Unsubscribe: --ybhwcA8vJ+NWw6Ag Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Dec 18, 2023 at 10:34:51AM -0800, Andrew Morton wrote: > On Sat, 16 Dec 2023 19:43:41 +0800 Kevin Hao wrote: >=20 > > A freezable kernel thread can enter frozen state during freezing by > > either calling try_to_freeze() or using wait_event_freezable() and its > > variants. However, there is no need to use both methods simultaneously. > > The freezable wait variants have been used in khugepaged_wait_work() > > and khugepaged_alloc_sleep(), so remove this unnecessary > > try_to_freeze(). > >=20 >=20 > Looks OK to me, but this will increase freezing latencies. How > significant is this? I don't think this would cause observable freezing latencies, and most of t= ime, we won't enter the freezing state, it is worthwhile to reduce the overhead = of a function call. On my Intel Alder Lake board (24 CPUs, 32G memory) with transparent hugepag= e enabled. Before this patch: Freezing user space processes Freezing user space processes completed (elapsed 0.000 seconds) OOM killer disabled. Freezing remaining freezable tasks Freezing remaining freezable tasks completed (elapsed 0.001 seconds) After this patch: Freezing user space processes Freezing user space processes completed (elapsed 0.000 seconds) OOM killer disabled. Freezing remaining freezable tasks Freezing remaining freezable tasks completed (elapsed 0.001 seconds) >=20 > Also, we already have a patch from you with this same title. Please > try to use different titles for different patches. Sure, I will tweak it in v2. Thanks, Kevin --ybhwcA8vJ+NWw6Ag Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEHc6qFoLCZqgJD98Zk1jtMN6usXEFAmWA53oACgkQk1jtMN6u sXGGBQgAyM8L23mBQplJbU0pT8Z1lR+Lon8WiixrIPvE0X1COznG/qjAxNdpVxft 4U/YI2PfJF3KOBhnIlxJxe32/aDCD8Texg1XqShwbfwsSoAIh+WV0zkDdwAbqscD ImK7Mfw5iow6olAABVK436VErZbXpFqTVg7nQ6n9K1fsofqhDhWoORxEaQgqVNZ7 wPRrFAVnfDeNZ+Lzyy6O8zw6WYJ/39mR8IKIGn/jJxS4+V/a8N/wkGNKD35fTd5q 02qAchYuBaUb1/w/2r4D3i6bhXUyIenZ1vb7p+nrk9Fw1uyJy/alGoBcTbVY1i3m jXcbB8Gqo8QL6NIiU2Ig7nrbF93i5w== =tFQJ -----END PGP SIGNATURE----- --ybhwcA8vJ+NWw6Ag--