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]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 15C02D7496F for ; Fri, 19 Dec 2025 09:31:22 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 668496B0088; Fri, 19 Dec 2025 04:31:22 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 653266B0089; Fri, 19 Dec 2025 04:31:22 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 56A176B008A; Fri, 19 Dec 2025 04:31:22 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id 406486B0088 for ; Fri, 19 Dec 2025 04:31:22 -0500 (EST) Received: from smtpin08.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay04.hostedemail.com (Postfix) with ESMTP id EDAA41A0509 for ; Fri, 19 Dec 2025 09:31:21 +0000 (UTC) X-FDA: 84235702362.08.A9A3710 Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by imf21.hostedemail.com (Postfix) with ESMTP id 593121C000A for ; Fri, 19 Dec 2025 09:31:20 +0000 (UTC) Authentication-Results: imf21.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=SvcBAeCu; spf=pass (imf21.hostedemail.com: domain of broonie@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=broonie@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1766136680; 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=j8TZc5XwPNYMEoE4seJjAVwVtp8dsPoJJX4kIRgwWZM=; b=tEoZJnpPNkgY4zo3F+pSIXgISGuGL1POSsXyBgifQkY2+0iLCiu41+0dKAO1+nNrL8bacx 6TCuglth+jyl2ERX8YHAUCJ01hTI9lw63OqRJ8lywiACqGJnXlEbvXpoaMU8HbZgIB9Bck cfGNGiOOTDgqbBNwl1PmcueHgA/i4Hs= ARC-Authentication-Results: i=1; imf21.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=SvcBAeCu; spf=pass (imf21.hostedemail.com: domain of broonie@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=broonie@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1766136680; a=rsa-sha256; cv=none; b=BHxyZuhcj80kLk9U/7PmXeb6jInmeZnhmeWLP3mwwrfV3EZ1xr9Xugl8g35jDAYQqXJqUw I9pqt2dK0wOmwS+1ycklqLjiibmbkxkShN2U6ExUQF1EN1sNNO8m/ZwqJ4BeSMfnUWb0iA v0xDVqV6Zprtxd7crN4uDyizVB0nvks= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id D4FE360018; Fri, 19 Dec 2025 09:31:19 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 38C49C4CEF1; Fri, 19 Dec 2025 09:31:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1766136679; bh=JDYyYGh8RrQI+zVY9L46NOe+/hWd6ylKrEcBti0g6qI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=SvcBAeCu/Pdh7bz9GUGnJaSUHchFxGcvlI53HUKKzdzPql2UPl+smqieCqxW1wsQZ EuoSKZEsntAzSe7zk6TKtg6GbVQJc+dU4H5Lq7/CRLTB0J7l2sP9cJQn0HJliWUu6B z/Zc64Ldf8XVFX+m5hUYl5sEYIXrETQG/TxcJeHkijpPLPwiHDjRyLOPTOORnsv/64 cG6ZES1auagKZSszkJHI/LpAOHg6S0LU3FokQuuGl3jvEOGufr1Dwy8faUAoP3z8Tc ZKAd1OAGMCgQ8lofMQAk7vNtl10f6FWCCOuhf45N99nAuDYF6mxrcTKNE4tipo8/ES 1VVHQZMet/rHQ== Date: Fri, 19 Dec 2025 09:31:10 +0000 From: Mark Brown To: Mathieu Desnoyers Cc: Thomas Gleixner , Andrew Morton , linux-kernel@vger.kernel.org, "Paul E. McKenney" , Steven Rostedt , Masami Hiramatsu , Dennis Zhou , Tejun Heo , Christoph Lameter , Martin Liu , David Rientjes , christian.koenig@amd.com, Shakeel Butt , SeongJae Park , Michal Hocko , Johannes Weiner , Sweet Tea Dorminy , Lorenzo Stoakes , "Liam R . Howlett" , Mike Rapoport , Suren Baghdasaryan , Vlastimil Babka , Christian Brauner , Wei Yang , David Hildenbrand , Miaohe Lin , Al Viro , linux-mm@kvack.org, linux-trace-kernel@vger.kernel.org, Yu Zhao , Roman Gushchin , Mateusz Guzik , Matthew Wilcox , Baolin Wang , Aboorva Devarajan , Aishwarya TCV Subject: Re: [PATCH v10 2/3] mm: Fix OOM killer inaccuracy on large many-core systems Message-ID: <2a772584-2269-4008-809a-6123e226ebe3@sirena.org.uk> References: <20251213185608.3418096-1-mathieu.desnoyers@efficios.com> <20251213185608.3418096-3-mathieu.desnoyers@efficios.com> <72ad1fed-574e-4850-beac-91626e5aaa0e@efficios.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="nB8gAt2CMqOecX2t" Content-Disposition: inline In-Reply-To: <72ad1fed-574e-4850-beac-91626e5aaa0e@efficios.com> X-Cookie: Save gas, don't eat beans. X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: 593121C000A X-Stat-Signature: sph58iogohy1tft5b5fieitet4ft11eg X-Rspam-User: X-HE-Tag: 1766136680-55045 X-HE-Meta: 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 ezd2z9F6 K6hqMLQt8if+0de0mAPeVlkTtK6mFBZJnYscgsJqn76v50PocWHFTV5GElzsidDSdTOrC77ImSU+zmf6PFquYF9i8XH+KDXZFNI4mJFLxYPRf+RB2loN4rgEjdjHMbLJc8L9EL7+e75TdjKkKUUVmF04kPAyw7uUR/RrhO1cRngCR0nyYLP5/8R9Ce9OkiVv+CViR1RGKoR7rMcUxjg5AwDjE5hSVzMDGUCqvejDksaXouVZfHNqIU/cRr3sp0w3qYx/z/YDXQ3/MX/iwZFUbEnEbPBrvqCxRoG6BibBUtugDHGfJptLRCxXygZ7USWUntiyQCePDBV5SIXmWj6wPpRilzluButkyr5O119F9Hb/JcI5UPxMkxdFqr/PXrwjdq2do 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: --nB8gAt2CMqOecX2t Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Thu, Dec 18, 2025 at 05:18:04PM -0500, Mathieu Desnoyers wrote: > On 2025-12-18 13:00, Mark Brown wrote: > An ugly work-around that may work (and then we can improve on this), > at the end of mm/init-mm.c:init_mm (completely untested): > .cpu_bitmap = { [0 ... ((3*BITS_TO_LONGS(NR_CPUS))-1 + ((69905 * NR_MM_COUNTERS * 64) / BYTES_PER_LONG))] = 0UL }, That doesn't seem to fix the FVP unfortunately (BYTES_PER_LONG doesn't exist, but even just deleting the division entirely fails in the same way). --nB8gAt2CMqOecX2t Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAmlFG10ACgkQJNaLcl1U h9DefQf+JvhAM2zVW8yicN4Cg9fpYL03mrmvjIMlhXaVtEKithjABrlXzEEnlEg+ +zjtAMmjdy6Rk/9g54g3fYkcixYEqyyUsVAW9NMMWs+zzvVRaDvol9QqVeuaSn4g 6IpUfrPOtlWq6PKKMhcCiLmiK2Rh+83F0NJYtr2/NpDNmg2pelTUgURJa3+6FRsv LxhkCeEDvayR0U6J4PT3iDQrRACrqkLZ+tXAArOS/jQ9BPC4yQhXfCISptkXadbI 8fnQKlQUlAPh8OJN2lqiqUZWJ0z+OTl4/s5MKoRqB6sEh6bI6vftmyZCcFF7rjlW w2PeciwdUO+nJz/TS73YbVRA72dd9Q== =7twn -----END PGP SIGNATURE----- --nB8gAt2CMqOecX2t--