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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2B010EB64D9 for ; Fri, 7 Jul 2023 14:44:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232888AbjGGOol (ORCPT ); Fri, 7 Jul 2023 10:44:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34554 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229755AbjGGOoi (ORCPT ); Fri, 7 Jul 2023 10:44:38 -0400 Received: from smtp-out1.suse.de (smtp-out1.suse.de [IPv6:2001:67c:2178:6::1c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7A85C1FD7 for ; Fri, 7 Jul 2023 07:44:34 -0700 (PDT) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id 31B5221E84; Fri, 7 Jul 2023 14:44:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1688741073; h=from:from:reply-to: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=ZVMmLaENPaM0JjXRiuX3xuMS8784Ru8KYNLD4w1UHB4=; b=gY16RP7UTDxhFJM2hnrjCGu6gLgj1ACcLbJSPiViO60JctutlSt7kRGD6KBsq9dt4yCgTX 7Bjq2+UxfpV0ghSg/FJHi/C5r5ezI9TzDz3CcxXimErfiEl1gNhX9lpFEcozGWkxexZ8Wa eZ/jBuMEYFz7xH24+i+Pq8BGdrpViZY= Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 10997139E0; Fri, 7 Jul 2023 14:44:33 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id K9bHAdEkqGTRfQAAMHmgww (envelope-from ); Fri, 07 Jul 2023 14:44:33 +0000 Date: Fri, 7 Jul 2023 16:44:32 +0200 From: Michal Hocko To: =?utf-8?B?6LS65Lit5Z2k?= Cc: minchan@kernel.org, senozhatsky@chromium.org, david@redhat.com, yosryahmed@google.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [External] Re: [RFC PATCH 0/2] zram: objects charge to mem_cgroup Message-ID: References: <20230707044613.1169103-1-hezhongkun.hzk@bytedance.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri 07-07-23 22:25:48, 贺中坤 wrote: > > Please state the objective you are trying to achieve by this patchset. > > It is always good to summarize the previous discussion and mention what > > is done differently or how previous review feedback has been addressed > > but the overall idea/purpose should be always explicit. > > > > Please elaborate more about both. > > > > Thanks for your reply. > objective： > the compressed memory of zram charge to the cgroup of the user. Why do we want/need that? > summarize the previous discussion: > [1] As I can see, Michal's concern is that the charges are going to fail > and swapout would fail. > > The indirect use of zram is in the context of PF_MEMALLOC, so > the charge must be successful. No, this was not my concern. Please read through that more carefully. My concern was that the hard limit reclaim would fail. PF_MEMALLOC will not help in that case as this is not a global reclaim path. Also let's assume you allow swapout charges to succeed similar to PF_MEMALLOC. That would mean breaching the limit in an unbounded way, no? -- Michal Hocko SUSE Labs