From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from shelob.surriel.com (shelob.surriel.com [96.67.55.147]) (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 BC83C14AD2E; Tue, 14 Jan 2025 17:01:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=96.67.55.147 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736874086; cv=none; b=ngoAClRhE2TsVxeLQMqshJRloC2+g3+xp9K89I9lEc1pBQoIdpttyOk1KQENqgwYFSTVLamu/5HBmgU3CcjwZ09HVmYwCaN/5yi1BuPGATr0hPchNY4h3xqbcZ+PC4hI/uW/POcKavgy8IyOjtj8kWZQZdRpfOInTXy6Md83cDo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736874086; c=relaxed/simple; bh=R88i/iRzxO2ixybo41pWF1KELxLSXSWNqc/8wXFSIqE=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=i1LlmwaYyFjcL1wyMql6In5FHpXdV7h0eUeoyaBjWnFfg/u3ZoF99e5Ho8GW6rp2Gz0m5J85RoJuqGJHDYf1FpU1wlUxft66/9GFRDjCut99FNmdDTBE+F/shEvSsS9qWYsOfUpJMTkFockMlRyxkotXgqsYCjdpnQR/lf6nPXk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=surriel.com; spf=pass smtp.mailfrom=shelob.surriel.com; arc=none smtp.client-ip=96.67.55.147 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=surriel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=shelob.surriel.com Received: from fangorn.home.surriel.com ([10.0.13.7]) by shelob.surriel.com with esmtpsa (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.97.1) (envelope-from ) id 1tXkDf-0000000008F-0ZN1; Tue, 14 Jan 2025 11:56:47 -0500 Message-ID: <298822027ef468c290a67fe98e228348e2b389de.camel@surriel.com> Subject: Re: [PATCH v2] memcg: allow exiting tasks to write back data to swap From: Rik van Riel To: Michal Hocko , Johannes Weiner Cc: Yosry Ahmed , Balbir Singh , Roman Gushchin , hakeel Butt , Muchun Song , Andrew Morton , cgroups@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, kernel-team@meta.com, Nhat Pham Date: Tue, 14 Jan 2025 11:56:47 -0500 In-Reply-To: References: <20241212115754.38f798b3@fangorn> <20241212183012.GB1026@cmpxchg.org> <20250114160955.GA1115056@cmpxchg.org> Autocrypt: addr=riel@surriel.com; prefer-encrypt=mutual; keydata=mQENBFIt3aUBCADCK0LicyCYyMa0E1lodCDUBf6G+6C5UXKG1jEYwQu49cc/gUBTTk33A eo2hjn4JinVaPF3zfZprnKMEGGv4dHvEOCPWiNhlz5RtqH3SKJllq2dpeMS9RqbMvDA36rlJIIo47 Z/nl6IA8MDhSqyqdnTY8z7LnQHqq16jAqwo7Ll9qALXz4yG1ZdSCmo80VPetBZZPw7WMjo+1hByv/ lvdFnLfiQ52tayuuC1r9x2qZ/SYWd2M4p/f5CLmvG9UcnkbYFsKWz8bwOBWKg1PQcaYHLx06sHGdY dIDaeVvkIfMFwAprSo5EFU+aes2VB2ZjugOTbkkW2aPSWTRsBhPHhV6dABEBAAG0HlJpayB2YW4gU mllbCA8cmllbEByZWRoYXQuY29tPokBHwQwAQIACQUCW5LcVgIdIAAKCRDOed6ShMTeg05SB/986o gEgdq4byrtaBQKFg5LWfd8e+h+QzLOg/T8mSS3dJzFXe5JBOfvYg7Bj47xXi9I5sM+I9Lu9+1XVb/ r2rGJrU1DwA09TnmyFtK76bgMF0sBEh1ECILYNQTEIemzNFwOWLZZlEhZFRJsZyX+mtEp/WQIygHV WjwuP69VJw+fPQvLOGn4j8W9QXuvhha7u1QJ7mYx4dLGHrZlHdwDsqpvWsW+3rsIqs1BBe5/Itz9o 6y9gLNtQzwmSDioV8KhF85VmYInslhv5tUtMEppfdTLyX4SUKh8ftNIVmH9mXyRCZclSoa6IMd635 Jq1Pj2/Lp64tOzSvN5Y9zaiCc5FucXtB9SaWsgdmFuIFJpZWwgPHJpZWxAc3VycmllbC5jb20+iQE +BBMBAgAoBQJSLd2lAhsjBQkSzAMABgsJCAcDAgYVCAIJCgsEFgIDAQIeAQIXgAAKCRDOed6ShMTe g4PpB/0ZivKYFt0LaB22ssWUrBoeNWCP1NY/lkq2QbPhR3agLB7ZXI97PF2z/5QD9Fuy/FD/jddPx KRTvFCtHcEzTOcFjBmf52uqgt3U40H9GM++0IM0yHusd9EzlaWsbp09vsAV2DwdqS69x9RPbvE/Ne fO5subhocH76okcF/aQiQ+oj2j6LJZGBJBVigOHg+4zyzdDgKM+jp0bvDI51KQ4XfxV593OhvkS3z 3FPx0CE7l62WhWrieHyBblqvkTYgJ6dq4bsYpqxxGJOkQ47WpEUx6onH+rImWmPJbSYGhwBzTo0Mm G1Nb1qGPG+mTrSmJjDRxrwf1zjmYqQreWVSFEt26tBpSaWsgdmFuIFJpZWwgPHJpZWxAZmIuY29tP okBPgQTAQIAKAUCW5LbiAIbIwUJEswDAAYLCQgHAwIGFQgCCQoLBBYCAwECHgECF4AACgkQznneko TE3oOUEQgAsrGxjTC1bGtZyuvyQPcXclap11Ogib6rQywGYu6/Mnkbd6hbyY3wpdyQii/cas2S44N cQj8HkGv91JLVE24/Wt0gITPCH3rLVJJDGQxprHTVDs1t1RAbsbp0XTksZPCNWDGYIBo2aHDwErhI omYQ0Xluo1WBtH/UmHgirHvclsou1Ks9jyTxiPyUKRfae7GNOFiX99+ZlB27P3t8CjtSO831Ij0Ip QrfooZ21YVlUKw0Wy6Ll8EyefyrEYSh8KTm8dQj4O7xxvdg865TLeLpho5PwDRF+/mR3qi8CdGbkE c4pYZQO8UDXUN4S+pe0aTeTqlYw8rRHWF9TnvtpcNzZw== Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.54.1 (3.54.1-1.fc41) Precedence: bulk X-Mailing-List: cgroups@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Sender: riel@surriel.com On Tue, 2025-01-14 at 17:54 +0100, Michal Hocko wrote: > O > Btw. is there any actual reason why we cannot go nomem without going > to the oom killer (just to bail out) and go through the whole cycle > again? That seems arbitrary and simply burning a lot of cycle without > much chances to make any better outcome >=20 > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > index 7b3503d12aaf..eb45eaf0acfc 100644 > --- a/mm/memcontrol.c > +++ b/mm/memcontrol.c > @@ -2268,8 +2268,7 @@ int try_charge_memcg(struct mem_cgroup *memcg, > gfp_t gfp_mask, > =C2=A0 if (gfp_mask & __GFP_RETRY_MAYFAIL) > =C2=A0 goto nomem; > =C2=A0 > - /* Avoid endless loop for tasks bypassed by the oom killer > */ > - if (passed_oom && task_is_dying()) > + if (task_is_dying()) > =C2=A0 goto nomem; > =C2=A0 > =C2=A0 /* When we return from the page fault handler, we restart the instruction that faulted. That means we could just end up repeating the same fault over and over again. --=20 All Rights Reversed.