From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=suse.com header.i=@suse.com header.b="cAWK9vir" Received: from smtp-out1.suse.de (smtp-out1.suse.de [IPv6:2a07:de40:b251:101:10:150:64:1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7ABD8A3; Tue, 28 Nov 2023 01:38:42 -0800 (PST) Received: from imap1.dmz-prg2.suse.org (imap1.dmz-prg2.suse.org [10.150.64.97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id 2293821989; Tue, 28 Nov 2023 09:38:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1701164321; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=+KUlvMVVq0kzWkSg0J1DwGMUzVoldnKYXOLEGIYlAks=; b=cAWK9virywTZ532MDIgO1gy44OyyHrGCDU3wFS4vwwkNsW/vKW1ledm8n6gZv1rRBCK5ny TGnyw24WV2gXW3ycdO9GlCA3lf2XXWbkgTirCzOlLMWXWGyWWHV7V6juL75W9SKAKHOsKJ SjyuFMC7qaohToamRE1g+RCeRp6vxrA= Received: from imap1.dmz-prg2.suse.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by imap1.dmz-prg2.suse.org (Postfix) with ESMTPS id F25001343E; Tue, 28 Nov 2023 09:38:40 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id 23klOCC1ZWVtYgAAD6G6ig (envelope-from ); Tue, 28 Nov 2023 09:38:40 +0000 Date: Tue, 28 Nov 2023 10:38:40 +0100 From: Michal Hocko To: Nhat Pham Cc: akpm@linux-foundation.org, hannes@cmpxchg.org, cerasuolodomenico@gmail.com, yosryahmed@google.com, sjenning@redhat.com, ddstreet@ieee.org, vitaly.wool@konsulko.com, roman.gushchin@linux.dev, shakeelb@google.com, muchun.song@linux.dev, chrisl@kernel.org, linux-mm@kvack.org, kernel-team@meta.com, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org, shuah@kernel.org Subject: Re: [PATCH v6 2/6] memcontrol: allows mem_cgroup_iter() to check for onlineness Message-ID: References: <20231127193703.1980089-1-nphamcs@gmail.com> <20231127193703.1980089-3-nphamcs@gmail.com> Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20231127193703.1980089-3-nphamcs@gmail.com> Authentication-Results: smtp-out1.suse.de; none X-Spam-Level: X-Spam-Score: -2.02 X-Spamd-Result: default: False [-2.02 / 50.00]; ARC_NA(0.00)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; FROM_HAS_DN(0.00)[]; TO_DN_SOME(0.00)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; FREEMAIL_ENVRCPT(0.00)[gmail.com]; MIME_GOOD(-0.10)[text/plain]; NEURAL_HAM_LONG(-1.00)[-1.000]; RCVD_COUNT_THREE(0.00)[3]; DKIM_SIGNED(0.00)[suse.com:s=susede1]; RCPT_COUNT_TWELVE(0.00)[19]; FREEMAIL_TO(0.00)[gmail.com]; FUZZY_BLOCKED(0.00)[rspamd.com]; FROM_EQ_ENVFROM(0.00)[]; MIME_TRACE(0.00)[0:+]; MID_RHS_NOT_FQDN(0.50)[]; FREEMAIL_CC(0.00)[linux-foundation.org,cmpxchg.org,gmail.com,google.com,redhat.com,ieee.org,konsulko.com,linux.dev,kernel.org,kvack.org,meta.com,vger.kernel.org]; RCVD_TLS_ALL(0.00)[]; BAYES_HAM(-1.42)[91.09%] On Mon 27-11-23 11:36:59, Nhat Pham wrote: > The new zswap writeback scheme requires an online-only memcg hierarchy > traversal. Add a new parameter to mem_cgroup_iter() to check for > onlineness before returning. Why is this needed? -- Michal Hocko SUSE Labs