From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from m16.mail.126.com (m16.mail.126.com [117.135.210.8]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 5DBA42550B4 for ; Fri, 6 Jun 2025 06:31:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=117.135.210.8 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749191521; cv=none; b=cZXR0GegZgTGW29JrtJFLLpUlj+r3P4t84hWlx27XHe2MZKZNLZPLJEoPFXjOvDmrsnSHgYx8BVAa4Nx8QYM+j5rSs6E/zUY69mrvMnifqGzXpR5FwuIQTTEFYpYgsMCHxwdzUNMH1a1nm5VIFO6N0Ob7x7OK4EDOMtOfu5Zy64= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749191521; c=relaxed/simple; bh=twRi+HAcOCoN8kNjPgqZNRZo3pWlLxYUYgi6AF6k4gM=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=XaRm6bfYTAUHHIDnDYjlgGuLPbqC+38JHKvdOAaxfx6G0yLJzmzFUzQma2VOHyM/jCtn0kXCwgiXycCQGal5tS9pib+sCY33UvkucVbwm65vDO4KusOrWCGQyMEAY+4V03Mc16bxmhgaeCDtSUCho+GVmoiB8uxsgDPEOMTifbc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=126.com; spf=pass smtp.mailfrom=126.com; dkim=pass (1024-bit key) header.d=126.com header.i=@126.com header.b=psEsKbkL; arc=none smtp.client-ip=117.135.210.8 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=126.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=126.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=126.com header.i=@126.com header.b="psEsKbkL" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=126.com; s=s110527; h=Message-ID:Date:MIME-Version:Subject:To:From: Content-Type; bh=VlkXIqbrHLNm6KB283mzI4Nr/emCcxR2Gwn0N2hg5lw=; b=psEsKbkLFnDrIJ2bRJQpP0KZD8fbbK97QG2hPjjn+DTmY68UBdlBYHe5CYr7RQ 4GSwwR2osODvKK0WXu+aUYEGodv48mxz+gq5S4C1y2FMpGZhFHyaMFuzjwiWG+JE nWxOBn/0c2FZV1W3AOAk9R8rCoNPN4ChWqAltmScKbojg= Received: from [172.19.20.199] (unknown []) by gzsmtp3 (Coremail) with SMTP id PikvCgD3h7iKgEJolGIhBA--.42221S2; Fri, 06 Jun 2025 13:45:47 +0800 (CST) Message-ID: Date: Fri, 6 Jun 2025 13:45:46 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH V2] mm/hugetlb: remove unnecessary holding of hugetlb_lock To: Andrew Morton Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, 21cnbao@gmail.com, david@redhat.com, baolin.wang@linux.alibaba.com, muchun.song@linux.dev, osalvador@suse.de, liuzixing@hygon.cn References: <1748317010-16272-1-git-send-email-yangge1116@126.com> <20250604154754.a30e327c3f1640173c8b9cb8@linux-foundation.org> <20250605181242.54767f38223f9ebd4c379ccb@linux-foundation.org> From: Ge Yang In-Reply-To: <20250605181242.54767f38223f9ebd4c379ccb@linux-foundation.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-CM-TRANSID:PikvCgD3h7iKgEJolGIhBA--.42221S2 X-Coremail-Antispam: 1Uf129KBjvdXoWrKrW5Jw13uF45ury7Gw4rXwb_yoWkKrc_ur 1kZ3s7Cw4UW3yqga1ktrZFvrsxK3yxZrZ5Jay0krZ7Aas7XF13WFs3tana9Fs3Wa1kJFnr Wr90gwsIyr4jgjkaLaAFLSUrUUUUjb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUvcSsGvfC2KfnxnUUI43ZEXa7IU8OdbUUUUUU== X-CM-SenderInfo: 51dqwwjhrrila6rslhhfrp/1tbiOgxkG2hCeNjCwgAAsD 在 2025/6/6 9:12, Andrew Morton 写道: > On Thu, 5 Jun 2025 08:44:09 +0800 Ge Yang wrote: > >>> This change addresses a possible performance issue which was introduced >>> by 113ed54ad276 ("mm/hugetlb: fix kernel NULL pointer dereference when >>> replacing free hugetlb folios"). 113ed54ad276 was added recently and >>> was cc:stable. >>> >>> David said: >>> https://lkml.kernel.org/r/87521d93-cc03-480d-a2ef-3ef8c84481c9@redhat.com >>> >>> >>> Question is, will that bugfix's performance impact be sufficiently >>> serious for us to also backport this new patch? >> >> In some low-probability scenarios, there could be severe impacts. For >> example, when multiple CPUs execute the replace_free_hugepage_folios() >> function simultaneously. It seems that we need to backport this new >> patch. Thank you. > > OK, thanks. I added > > Fixes: 113ed54ad276 ("mm/hugetlb: fix kernel NULL pointer dereference when replacing free hugetlb folios") > Cc: > > and moved this to the mm-hotfixes pile. I'll keep it there for a week > or two for review/test. Once it goes upstream, this should propagate > into 6.15.x. Ok，thanks.