From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-179.mta1.migadu.com (out-179.mta1.migadu.com [95.215.58.179]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4B6BB3DB970 for ; Tue, 26 May 2026 10:14:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.179 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779790463; cv=none; b=qC3vi9D6i5JlTCPyKOM+R96JVwXVPOuw/dmesUTaX5V03woEpupsMW0eWTQ6185Cfr2KdSWArnYQk+i5pyQlOmA+uCgel8ifj+1CDXB8/aQCrqb60SnSk6UKFeePP8FuTdF3lZEAuvfLg4cu1ib8Pbfgx0NhNS18pbXWomDOvic= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779790463; c=relaxed/simple; bh=hSXqPEnkIRd9bKt10e8CjHLIGmiAoxY5OQIV6V1Ug/I=; h=Mime-Version:Content-Type:Date:Message-Id:From:To:Cc:Subject: References:In-Reply-To; b=FhfE2LwObIJd5uzc2lhHx6iFV83MNkV3euBCeifbnHN3drYaQibDPwmyPRvLAcbexftCFpYW5Lt5zwTMp1F4kuUmOKSOM3RSbi53xqDEZypyfBE73bTa8sqOLGNL6wAY/Fb/bth7JqNFFofhUgkxosw9WK2kmGVJVrdRQrdjOkc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=jWIRiwdb; arc=none smtp.client-ip=95.215.58.179 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="jWIRiwdb" Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1779790457; h=from:from: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:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=r5EPf91GvJGPsVarqCBeWWTgMarT2/Tha9nPfnXcEBs=; b=jWIRiwdbj/t0ezNDh2LuQtzAMDVrnAfYEFkhIktVPbe1TImIo17G6r0s/ZzDpY6oIQU6qs UMF1yPBDocJzOe1jscoEIM+nO0D1tjnqHW5wPfQ2lrz2KumfP0W0+JmaeIrOYHoMct95AH 8SMOcmf4yJqyjzUswo3l3PzsKkarTgk= Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=UTF-8 Date: Tue, 26 May 2026 12:14:02 +0200 Message-Id: X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: "Brendan Jackman" To: "Harry Yoo" , "Brendan Jackman" , "Andrew Morton" , "Vlastimil Babka" , "Suren Baghdasaryan" , "Michal Hocko" , "Johannes Weiner" , "Zi Yan" Cc: "Alexei Starovoitov" , , Subject: Re: [PATCH] mm/page_alloc: document that alloc_pages_nolock() uses RCU References: <20260519-nolock-rcu-comment-v1-1-4a630c8794e5@google.com> <6c089de3-34d9-4dd9-9646-f51328c77497@kernel.org> In-Reply-To: <6c089de3-34d9-4dd9-9646-f51328c77497@kernel.org> X-Migadu-Flow: FLOW_OUT On Wed May 20, 2026 at 5:16 AM CEST, Harry Yoo wrote: > > (I don't think there is even> any documentation of what noinstr means= =20 > at all, let alone the connection >> with RCU). > > *flips through the documentation* > Oh, perhaps Documentation/core-api/entry.rst? Oh, you're right. The situation is way better than I thought, and now I realise I have read this and it's probably where I learned about this in the first place (I thought I learned it all from Junaid). I apologise to the Documentation/ tree for my slander. >> Note this is not claiming that any cgroup code called from the allocator >> would actually break if this restriction was violated, it could very >> well be that there's no real way for the allocator to act on a cgroup >> that can disappear concurrently. But, since it's likely nobody has >> verified this one way or another, better to just be safe and declare >> that RCU is required. Allocating from an RCU-unsafe context seems a bit >> crazy anyway. >>=20 >> Suggested-by: Junaid Shahid > > The email should be junaids@google.com, not jackmanb@google.com? ;) Damn. It looks like this already went into mm-unstable but I guess it's not a huge deal.