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 E54DFC433F5 for ; Tue, 31 May 2022 02:46:31 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 6074A6B0074; Mon, 30 May 2022 22:46:31 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 5B5AE6B0078; Mon, 30 May 2022 22:46:31 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 4A28B6B007D; Mon, 30 May 2022 22:46:31 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id 3C3E56B0074 for ; Mon, 30 May 2022 22:46:31 -0400 (EDT) Received: from smtpin21.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 136BE2042A for ; Tue, 31 May 2022 02:46:31 +0000 (UTC) X-FDA: 79524499782.21.B315C13 Received: from out0.migadu.com (out0.migadu.com [94.23.1.103]) by imf12.hostedemail.com (Postfix) with ESMTP id 09A0040072 for ; Tue, 31 May 2022 02:45:49 +0000 (UTC) Date: Mon, 30 May 2022 19:46:20 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1653965188; h=from:from:reply-to:subject:subject: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=CWLskQLKMPVKxlcT8cF2mhzS9rXCoBmCHqKI67gGiCw=; b=f5jx0zSo1IDRLLA2GZuXmPBxAvu6IPoXlGGFIPAW6XeA5oP8KzsIUya+c1dZtZ3UwqO1Y6 alTzIKwUDxFq+Ya5GGK63RBl/slscys5MmU+WjXwPXiLMFoPRataIRfeAwFWACW+GEE26w rUWXxNveDigVU/2Y0MKCi5DvmbtlULU= X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Roman Gushchin To: Andrew Morton Cc: Muchun Song , hannes@cmpxchg.org, mhocko@kernel.org, shakeelb@google.com, cgroups@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, duanxiongchun@bytedance.com, longman@redhat.com Subject: Re: [PATCH v5 00/11] Use obj_cgroup APIs to charge the LRU pages Message-ID: References: <20220530074919.46352-1-songmuchun@bytedance.com> <20220530141711.6cf70dcf200e28aa40407f6e@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220530141711.6cf70dcf200e28aa40407f6e@linux-foundation.org> X-Migadu-Flow: FLOW_OUT X-Migadu-Auth-User: linux.dev X-Rspamd-Server: rspam08 X-Rspamd-Queue-Id: 09A0040072 X-Rspam-User: X-Stat-Signature: ip498bj51ns59w764kau68z6dn371t63 Authentication-Results: imf12.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=f5jx0zSo; dmarc=pass (policy=none) header.from=linux.dev; spf=pass (imf12.hostedemail.com: domain of roman.gushchin@linux.dev designates 94.23.1.103 as permitted sender) smtp.mailfrom=roman.gushchin@linux.dev X-HE-Tag: 1653965149-694480 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 Mon, May 30, 2022 at 02:17:11PM -0700, Andrew Morton wrote: > On Mon, 30 May 2022 15:49:08 +0800 Muchun Song wrote: > > > This version is rebased on v5.18. > > Not a great choice of base, really. mm-stable or mm-unstable or > linux-next or even linus-of-the-day are all much more up to date. > > Although the memcg reviewer tags are pretty thin, I was going to give > it a run. But after fixing a bunch of conflicts I got about halfway > through then gave up on a big snarl in get_obj_cgroup_from_current(). > > > RFC v1: https://lore.kernel.org/all/20210330101531.82752-1-songmuchun@bytedance.com/ > > Surprising, that was over a year ago. Why has is taken so long? It's partially my fault: I was thinking (and to some extent still are) that using objcg is not the best choice long-term and was pushing on the idea to used per-memcg lru vectors as intermediate objects instead. But it looks like I underestimated the complexity and a potential overhead of this solution. The objcg-based approach can solve the problem right now and it shouldn't bring any long-term issues. So I asked Muchun to revive the patchset. Thanks!