From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-yb1-f180.google.com (mail-yb1-f180.google.com [209.85.219.180]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E77E618024 for ; Wed, 6 Aug 2025 13:44:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.219.180 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754487849; cv=none; b=gLooroJB6uQMOS+6hCBnI/VoqJZfjc1mov1oXDGgzN6aX5qgYERmdYrPNW9T6dVJbgDzdOigRGqyI2HWBk2ksjjiCSYbI1tnmoFKz4NHQ2u+hPZaJ6HXoYkognX40/NrT8FW1gFL5LRJ0t/6ONFOnEmz7JrJdICWm/QUvlLf6xI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754487849; c=relaxed/simple; bh=XLv/Q50dhC2UQHHugrJSH55dAVdrays+hhdJJQ4Jrzo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=DSSJxTsgwEEigkJGUhyHTMct756wGCMfcGRklNAoFbQxSZlDVE4Gw1BavO0gXc0NgVrSGnKS69u1NlvZqJ4PEmbHB8ptoPSjGojzk+5HUy18md2AXwpGj4CGIfUND0GeQN0jMJSbs0xodFsUSDGO9LP4oYDz2+XrJNeYSpNXm6Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=c6T636V0; arc=none smtp.client-ip=209.85.219.180 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="c6T636V0" Received: by mail-yb1-f180.google.com with SMTP id 3f1490d57ef6-e901c374e7aso1658258276.1 for ; Wed, 06 Aug 2025 06:44:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1754487847; x=1755092647; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=N+BoskqRxZrTyHjmVFL6MiKmeRCMGEe1NmNgCqxmHtM=; b=c6T636V0C1cjB1B5xo9F8mN+AyjAN3X42gVWBxw6lHEPBGAfS8cDSHk9+gl5EYO0Zz D3L9pPVzBnGRL708P/WD+Eah15Lf4ahPh9VueNT0AokSaW1VCdyK1zcvySKeP0N4ToXO pURB3ghc7C0lx/eWAi/gNfBHBjvk5d2XFpsa96iTJvFEqRQXh8MGA8ecE5T7BHj5WDwC mHk3vFgY4S/+jOJ87lLXGS2LrCKR7bV6wojbFdg6eZYujRPrt5vefpzO+BKhJPjp6YPQ eOrM2A1wrrlHCb051hktmcfhQnbqeP7aJEOeBxfnSMOmNNirVpN56bEXU9cPBXzu9NSR y6Hw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1754487847; x=1755092647; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=N+BoskqRxZrTyHjmVFL6MiKmeRCMGEe1NmNgCqxmHtM=; b=XbHZLUao7uNxcmQ93F87xLzTNaY9NhWUptK7xDpLML5rksLjEePPm/ww7gVbVQ0R+8 prUB/9osV7Plj+Js9KUYTZAl/aEhjAdpEZ/OTzo28IbSjxGFncDAnPH0+gEybSaawKfL bmmp6oOL35/vPedHVPqPFamLpWdnNkIE1rBxszOvXgpEL1tF5QRsEJVYyaKXtgfl8SSI 1pb/pyoDEekFtGE12rMt1OkWZBztQRJu2pWkdDqlpSRSBM445jSpZHlIWbNGxXYXQM2X KGXRPu9Kk2/1k1ktG/cPA9jVI9KflNA/LUS/IcrsrONR6A/BwOSyMju+zU/ZVX45ZpKa RN7Q== X-Forwarded-Encrypted: i=1; AJvYcCXEqV0TMTJmmX6n351RuGA39cUcXmx/rG5j2F2hzAnd9DNoQiyLoOxRp5760SmS2TIbRcXzTxHvi/0zDJA=@vger.kernel.org X-Gm-Message-State: AOJu0Yzh5oNSONPNT3g7rrZjfGYCLZZYr6NhwTxzINkLEMvg1CBk2a25 Krxt1SEEazMJuzGQhn4indC2pubNnDFhCoIaqQebRh9jboN6RykfcwYX X-Gm-Gg: ASbGncviNr4PWnPwjvohf+tjubL758j5n9jbs8yRLrEWX6ILwqeSDrjgerRHk42a6Fw sOULdzSYKmfEhzoWpFfEcX8IvxHGE8fez/tEbONoFlWw37SW7B4advsOpUXKFE6RT17OvX/4Qv0 PxJc34t/tRuRrFTW/pNDZzXonFu0FYwUv3n6uz8tdYorH5HZYB7yRH0mVSGcmFML3c8JRsCxF6Z IcovGgtc18EIdWUsF45if1cDfLKTnPBLwnWRiG7ZIYviEnIHLakSNEYo58ySMeup2vyGDgQoQp9 lvdZSaF6vcUSgz0ygnCiqGKwpXCd1XaKENzMPVYIRfQB4Am6gfXl4sbNlh3vlT8gYfSQ9yYXdNz F01hd9YSfcUqtN5lCqOSJ3Q== X-Google-Smtp-Source: AGHT+IEawk87xQDQOVWUd1SSZMxS6FyCzOtqHsqYpXoO4yyDYZeLvgJgpUUMmfH9mL8lTAc1P0UXJQ== X-Received: by 2002:a05:6902:320e:b0:e87:b880:7dee with SMTP id 3f1490d57ef6-e90287695fbmr3351443276.12.1754487846599; Wed, 06 Aug 2025 06:44:06 -0700 (PDT) Received: from localhost ([2a03:2880:25ff:44::]) by smtp.gmail.com with ESMTPSA id 3f1490d57ef6-e8fd375267fsm5550223276.15.2025.08.06.06.44.06 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 06 Aug 2025 06:44:06 -0700 (PDT) From: Joshua Hahn To: "Huang, Ying" , Andrew Morton Cc: David Hildenbrand , SeongJae Park , Alistair Popple , Byungchul Park , Gregory Price , Matthew Brost , Rakie Kim , Zi Yan , linux-kernel@vger.kernel.org, linux-mm@kvack.org, kernel-team@meta.com Subject: Re: [PATCH v3] mempolicy: Clarify what zone reclaim means Date: Wed, 6 Aug 2025 06:43:52 -0700 Message-ID: <20250806134404.2000234-1-joshua.hahnjy@gmail.com> X-Mailer: git-send-email 2.47.3 In-Reply-To: <87zfcduv3l.fsf@DESKTOP-5N7EMDA> References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit On Wed, 06 Aug 2025 08:55:42 +0800 "Huang, Ying" wrote: > Joshua Hahn writes: > > > > /* > > + * Enabling zone reclaim means the page allocator will attempt to fulfill > > + * the allocation request on the current node by triggering reclaim and > > + * trying to shrink the current node. > > + * Fallback allocations on the next candidates in the zonelist are considered > > + * when reclaim fails to free up enough memory in the current node/zone. > > + * > > * These bit locations are exposed in the vm.zone_reclaim_mode sysctl > > - * ABI. New bits are OK, but existing bits can never change. > > + * ABI. New bits are OK, but existing bits should not be changed. > > Should we avoid to call sysctl ABI here? Hi Ying, Makes sense to me as well! Andrew -- I saw that you added this to mm-unstable yesterday, would you mind folding the small fixlet below in with it? Please let me know if you would rather that I send in a new version, whatever works best for you! As always, thank you for your help : -) Have a great day! Remove the reference to the vm.zone_reclaim_mode sysctl as an ABI. Signed-off-by: Joshua Hahn diff --git a/include/uapi/linux/mempolicy.h b/include/uapi/linux/mempolicy.h index 683c130782f0..8fbbe613611a 100644 --- a/include/uapi/linux/mempolicy.h +++ b/include/uapi/linux/mempolicy.h @@ -72,8 +72,8 @@ enum { * Fallback allocations on the next candidates in the zonelist are considered * when reclaim fails to free up enough memory in the current node/zone. * - * These bit locations are exposed in the vm.zone_reclaim_mode sysctl - * ABI. New bits are OK, but existing bits should not be changed. + * These bit locations are exposed in the vm.zone_reclaim_mode sysctl. + * New bits are OK, but existing bits should not be changed. */ #define RECLAIM_ZONE (1<<0) /* Enable zone reclaim */ #define RECLAIM_WRITE (1<<1) /* Writeout pages during reclaim */