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]) by smtp.lore.kernel.org (Postfix) with ESMTP id B5F9EC433FE for ; Thu, 13 Oct 2022 00:38:31 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 203766B0071; Wed, 12 Oct 2022 20:38:31 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 18CE46B0073; Wed, 12 Oct 2022 20:38:31 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 007C86B0074; Wed, 12 Oct 2022 20:38:30 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id DC2516B0071 for ; Wed, 12 Oct 2022 20:38:30 -0400 (EDT) Received: from smtpin16.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id B344EC0ECA for ; Thu, 13 Oct 2022 00:38:30 +0000 (UTC) X-FDA: 80014065180.16.58AD011 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by imf09.hostedemail.com (Postfix) with ESMTP id 360DB140026 for ; Thu, 13 Oct 2022 00:38:29 +0000 (UTC) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 4A041B81CC0; Thu, 13 Oct 2022 00:38:28 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id AD032C433D7; Thu, 13 Oct 2022 00:38:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1665621507; bh=fIBx0fk/i8Gefd9ZrizLeDWC35/uKkbdvMp4L+ilGNU=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=eNs9F9rFjafI66l1WW5TTwHbmhFJfSVZnqqopbkioUXtDKPK3ZXJ5vS3L3IWP7hEg 3mpiVdYUZhVOW1o8sirKSi/2D8i355P6m6fVomdolTfp+Flio7KfrTYPtJqpGDQUtB y0SIq1IsGnlPN9et7Rern9nsc3exKuFw0aqCtCtPxQF5M86EPfKdeJgu78+jctC4RH kViRiN6Elm0D4SWR4uRwsgsX/ufs0VoLz7wF8QlKNo8ooSjpPJy4eNXoW5d3oelkpz v2nNtb23iJq83ftiFPOcfb/QX7ToN8YGHxfj+llW+wIaCbm8TEY8mGrSXoP6tGT3Xc EjpdQTw0eq/CA== Date: Wed, 12 Oct 2022 17:38:25 -0700 From: Jakub Kicinski To: Shakeel Butt Cc: Wei Wang , Eric Dumazet , netdev@vger.kernel.org, "David S . Miller" , cgroups@vger.kernel.org, linux-mm@kvack.org, Roman Gushchin Subject: Re: [PATCH net-next] net-memcg: pass in gfp_t mask to mem_cgroup_charge_skmem() Message-ID: <20221012173825.45d6fbf2@kernel.org> In-Reply-To: References: <20210817194003.2102381-1-weiwan@google.com> <20221012163300.795e7b86@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1665621510; a=rsa-sha256; cv=none; b=lV/c6dyvvib4ymsZAC4sXBHQwuMZAeEXaJ+TvrCY9NkjhWZNhaElGOmOYwQCdXXOcgLUms wJDOeNlpiHFEJgGMlT2zgR/NySllqh12HG8kys7323HcD3JPIYbfTB/86/Cv+9G3AEzpuL z7325RiVeid/E87dLdOTm2OXQ7DqVAE= ARC-Authentication-Results: i=1; imf09.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=eNs9F9rF; spf=pass (imf09.hostedemail.com: domain of kuba@kernel.org designates 145.40.68.75 as permitted sender) smtp.mailfrom=kuba@kernel.org; dmarc=pass (policy=none) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1665621510; 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:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=D9jsP7qrybzf485j4XEvDZwZcuX0fkROHBOARKeM7aA=; b=dErSkC1LPVB8Rtivud/E5U/ruEWncjNNra4GqsKtxuNv6eN+l/jQxPoF7ROsPbyhfyj9IM mu2uGdtNYmmP1lmW1jQQ3YhGrWcf7kiv6WSjVIpGm1IpzgiOiV6NCgxAU6yHi1OkwNUaCb OGyikTFEO9Zamiu9Cedo6Ce8ukZvSTU= X-Stat-Signature: hb4r5kpf3ng7yynx3fztxkdfcfoafxui X-Rspamd-Queue-Id: 360DB140026 X-Rspam-User: X-Rspamd-Server: rspam08 Authentication-Results: imf09.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=eNs9F9rF; spf=pass (imf09.hostedemail.com: domain of kuba@kernel.org designates 145.40.68.75 as permitted sender) smtp.mailfrom=kuba@kernel.org; dmarc=pass (policy=none) header.from=kernel.org X-HE-Tag: 1665621509-865183 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: On Wed, 12 Oct 2022 17:17:38 -0700 Shakeel Butt wrote: > Did the revert of this patch fix the issue you are seeing? The reason > I am asking is because this patch should not change the behavior. > Actually someone else reported the similar issue for UDP RX at [1] and > they tested the revert as well. The revert did not fix the issue for > them. > > Wei has a better explanation at [2] why this patch is not the cause > for these issues. We're talking TCP here, to be clear. I haven't tested a revert, yet (not that easy to test with a real workload) but I'm relatively confident the change did introduce an "unforced" call, specifically this bit: @@ -2728,10 +2728,12 @@ int __sk_mem_raise_allocated(struct sock *sk, int size, int amt, int kind) { struct proto *prot = sk->sk_prot; long allocated = sk_memory_allocated_add(sk, amt); + bool memcg_charge = mem_cgroup_sockets_enabled && sk->sk_memcg; bool charged = true; - if (mem_cgroup_sockets_enabled && sk->sk_memcg && - !(charged = mem_cgroup_charge_skmem(sk->sk_memcg, amt))) + if (memcg_charge && + !(charged = mem_cgroup_charge_skmem(sk->sk_memcg, amt, + gfp_memcg_charge()))) where gfp_memcg_charge() is GFP_NOWAIT in softirq. The above gets called from (inverted stack): tcp_data_queue() tcp_try_rmem_schedule(sk, skb, skb->truesize) tcp_try_rmem_schedule() sk_rmem_schedule() __sk_mem_schedule() __sk_mem_raise_allocated() Is my confidence unjustified? :)