From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 F04AD1FBEBC; Tue, 7 Apr 2026 06:48:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775544507; cv=none; b=ACWsc/HGfC5phIOFYnXRBYTf9Uh49kDUgbeE2OiVXw0fihZO9M/vYdrx5VXOD70bcaArvbav2n6GeUhEQ/EsXswVZ3MML1/sJ15vQX5EB0WEpEO6nl+jZam24MmiSTEDmorr3kX9FTXDATD1wa7LK/cUQdW/oPQp6o1fEDRLh68= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775544507; c=relaxed/simple; bh=Ea/dgNWMCtrFcxVc9JR8+cREFl164xqobHdGsxImfvg=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=CUYJLYE0chho1KgCw2I/wwXrjotAS/yz1nfeOikHFQmXs1Ncj7SR7B6n8ArFHjHnOiBbS1kuJbOX5M9SWost4JS6QDq2KAbiqgvLsDYj/I2rdEFgsE8bGMoGxH5efoe7Ki9p1Eq2lWXOiwwG2DXr2BAa3bRFefU/De4hordLEAY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=OwWWkCfm; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="OwWWkCfm" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5D9A1C116C6; Tue, 7 Apr 2026 06:48:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1775544506; bh=Ea/dgNWMCtrFcxVc9JR8+cREFl164xqobHdGsxImfvg=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=OwWWkCfmwSJazt6Bl6SPLtj1PCppUfp38Lf0p9XHHEmjjh+JRHXNZTlPpsgc5ZrT6 HF+hnGowGlh0El7GD1dmDRBlKTxRvoTUeWng9Rq3yL8XQuBOeoIU6iWV+mwHe1Vc1G s6bsMuyDSlGRZgPHPI8oVfsOJm9b60+dLlml5UJlLxfA8cZkXEpj//0bws9rzxFROB Q+kXxxzJWzLIrR9OWXap6yZEKiQqz5V05GJ6xUCl9Ew6kfI3c3h/A/tTZgC6DIxOEk HYaMxGcUDSJXHfSqy7m/5WebBws7TkYXq5NePlRWkGnxGMSTQGUOFGMm3/nR7mJ8ar ROnSXMmw13vqA== Message-ID: Date: Tue, 7 Apr 2026 08:48:22 +0200 Precedence: bulk X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] perf/events: Replace READ_ONCE() with standard pgtable accessors To: Anshuman Khandual , linux-mm@kvack.org, Andrew Morton Cc: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Namhyung Kim , linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org References: <20260227062744.2215491-1-anshuman.khandual@arm.com> <1267a6c0-f8e7-4708-96da-4d131b5c6069@arm.com> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit On 4/7/26 05:28, Anshuman Khandual wrote: > > > On 27/02/26 11:57 AM, Anshuman Khandual wrote: >> Replace raw READ_ONCE() dereferences of pgtable entries with corresponding >> standard page table accessors pxdp_get() in perf_get_pgtable_size(). These >> accessors default to READ_ONCE() on platforms that don't override them. So >> there is no functional change on such platforms. >> >> However arm64 platform is being extended to support 128 bit page tables via >> a new architecture feature i.e FEAT_D128 in which case READ_ONCE() will not >> provide required single copy atomic access for 128 bit page table entries. >> Although pxdp_get() accessors can later be overridden on arm64 platform to >> extend required single copy atomicity support on 128 bit entries. >> >> Cc: Andrew Morton >> Cc: David Hildenbrand >> Cc: Peter Zijlstra >> Cc: Ingo Molnar >> Cc: Arnaldo Carvalho de Melo >> Cc: Namhyung Kim >> Cc: linux-perf-users@vger.kernel.org >> Cc: linux-mm@kvack.org >> Cc: linux-kernel@vger.kernel.org >> Acked-by: Peter Zijlstra (Intel) >> Signed-off-by: Anshuman Khandual >> --- >> This patch applies both on v7.0-rc1 and mm-unstable. >> >> Part of the D128 series but independent. Hence could be considered on its own. >> >> https://lore.kernel.org/all/20260224051153.3150613-5-anshuman.khandual@arm.com/ >> >> Collected Peter's tag from an off list conversation. > > Gentle ping. > > Still don't see this patch in latest next-20260406. Hence just > wondering which tree and branch this patch is being picked up ? It's a trivial change and the last generic code change required for you arm64 D128 change, right? I would assume this to go through the tip tree, but if Peter agrees we could route this (mm) patch through the MM tree. -- Cheers, David