From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mta0.migadu.com (out-160.mta0.migadu.com [91.218.175.160]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 769CB4EF14A for ; Thu, 17 Sep 2026 20:26:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.160 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789676811; cv=none; b=KmU8ijpZ5VnTX+ZQ028bzfMMwOMbxOlyANyR7QxFN47VNBxwvyvcC7fqHRxE+VkPNiEGZGGBY3sJ2rq7vi/HKx+WRUDnpfODTiBk7ACRQJT8m/O/2tJLRFHtbKvZ1ESbJa3yVb44GP3fM28Ff7YBgH3zII/wY9H2pKwgVH0xW/g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789676811; c=relaxed/simple; bh=IymYpdktmr2T4Y5nV+Oxbm/h4xXa2qb7o9DAxlo2Xn0=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=qO0ondSr5Kmyh6k6LI6ba+d6E4y3V/HP8JJtlSMj1gqq9X2siUE+PtJh4LDWtuDbO8pi7kh7seEMBiJT6QH4y67tiURjuXZrvZ/y/N55DOlAGFwbLXNDZCtVx9mZWOtmyDeoSmEImXm12jwWme+YIM6lodNVrtIa6gmV2pdIMPU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=D4pmKdxh; arc=none smtp.client-ip=91.218.175.160 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="D4pmKdxh" X-Envelope-To: linux-kernel@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=IymYpdktmr2T4Y5nV+Oxbm/h4xXa2qb7o9DAxlo2Xn0=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1789676806; v=1; x=1790281606; b=D4pmKdxhFVZQFivGakGVOSrbvSKbZEBdyCjj4lGV6icshBRbqhP0wfoG4pG19ksSNEqjl1yM Ofu6j1bY3qoTBen7GlUiQHRiD4JQ4RFAd7b72QkQqDt39PRjCXSVvkzG80oNq8a0aoXMyLNHK1p hUboxtUeSqOiYwVgIw/c67As= X-Envelope-To: linux-kernel@vger.kernel.org Received: by smtp.migadu.com with ESMTPS id 5c187154c223a05e; Thu, 17 Sep 2026 20:26:45 +0000 X-Mizu-Trace-ID: 5c187154c223a05e X-Migadu-Flow: FLOW_OUT Date: Thu, 17 Sep 2026 13:26:40 -0700 From: Shakeel Butt To: Tao Cui Cc: hannes@cmpxchg.org, mhocko@kernel.org, roman.gushchin@linux.dev, muchun.song@linux.dev, cgroups@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Tao Cui Subject: Re: [RFC PATCH 0/3] mm, memcg: isolate deprecated v1 state from struct mem_cgroup Message-ID: References: <20260916125737.1095414-1-cui.tao@linux.dev> Precedence: bulk X-Mailing-List: linux-kernel@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: <20260916125737.1095414-1-cui.tao@linux.dev> On Wed, Sep 16, 2026 at 08:57:34PM +0800, Tao Cui wrote: > From: Tao Cui > > The legacy cgroup v1 memory controller has already been moved out of > the shared implementation at the file level (mm/memcontrol-v1.c) and at > the Kconfig level (CONFIG_MEMCG_V1, default n since 6.11). Its > per-cgroup state, however, still sits as individual members inside > struct mem_cgroup, guarded by #ifdefs. > > This series isolates the deprecated implementation from the shared hot > structure: all v1-only members are grouped into a dedicated > struct mem_cgroup_v1, and every access goes through memcg->v1.X. > > With this in place the v1 implementation is self-contained: its > interface in mm/memcontrol-v1.c, its state in struct mem_cgroup_v1, and > its eventual removal becomes a localized deletion of this struct > together with mm/memcontrol-v1.c, instead of unwinding > ifdef-scattered members across the shared header. Sorry I don't see any benefit of this code churn. The code is already behind config. What exactly this code churn is giving us?