From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DE47018E3F; Tue, 19 Aug 2025 02:41:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.50.34 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755571295; cv=none; b=mn7gK4Rp6L4Lp8O0gOQGtnMtPYnE396M6/nl+N7gOCioNm0V7QG3Vwx9cH8PbE33HXPEylsCK0JFDekp4rpe0vshwUVJ6SgAC9uzxzflCkS3OtvNmhX8fQAm28WRiiYSbHFYvuNVq/ID29CyjOacfkHrzEMHi/Lt9xmJotF55d0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755571295; c=relaxed/simple; bh=KMGyNtjtrLCyv9tEVPwvf74AtviAE4WX4hdDglb3nAo=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Jq6zfsIVe/G4Hd0ZjQSEa6Kajv1Rs+klfUJQ8dle5mq5aBkiHMTtJoRjUPSqjNFd/mR+sPYQPT56QjgNCuaIbC1MC57fbAZfjRpqiJhpGdmvKHaxid4I+BLJxSu+RTvY9duE4FevjyrQJhlhyHd3xFNug3d4bFtaHZ8QKrzguEs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=H70igcBq; arc=none smtp.client-ip=90.155.50.34 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="H70igcBq" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=mTBnV4bc3gSI0g52nwjGpXSW5TVHNqW9pyIpZEnrk9I=; b=H70igcBqpiQYNo4ugKW1YZfnad 8lQrxV0D0gUVaU/APagwXs/155/NS4GN7t+bC/zBBA0yfNIjPjhxWAXtRIPkkOw9QdyIlxFGas5Yx +QFeKcKhEKJHyk5nArTo1z2LacZut1/Bf5u/YrCyvEv96NGQzlJR5YwWTV0KJoBP1tFOoqPKicLyL tks+q7GgC/4zitDwaq3H2Y7WRqHG3AlADNJjQmRAN3VFwgy8h1fywRt6driRb31fYYIhPGlDIie6Z ojKTebYkz/dCWa71jznojegmy0VlcGxa0ctu0Pl+CFcG4F9UECWNqFM9IinKKKywDGEfXOhA6bFvg dZ89j+2g==; Received: from willy by casper.infradead.org with local (Exim 4.98.2 #2 (Red Hat Linux)) id 1uoCHy-0000000EwLT-2pYe; Tue, 19 Aug 2025 02:41:30 +0000 Date: Tue, 19 Aug 2025 03:41:30 +0100 From: Matthew Wilcox To: Boris Burkov Cc: akpm@linux-foundation.org, linux-btrfs@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, kernel-team@fb.com, shakeel.butt@linux.dev, wqu@suse.com, mhocko@kernel.org, muchun.song@linux.dev, roman.gushchin@linux.dev, hannes@cmpxchg.org Subject: Re: [PATCH v3 4/4] memcg: remove warning from folio_lruvec Message-ID: References: <0cf22669a203b8671b6774408bfa4864ba3dbf60.1755562487.git.boris@bur.io> Precedence: bulk X-Mailing-List: linux-fsdevel@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: <0cf22669a203b8671b6774408bfa4864ba3dbf60.1755562487.git.boris@bur.io> On Mon, Aug 18, 2025 at 05:36:56PM -0700, Boris Burkov wrote: > Commit a4055888629bc ("mm/memcg: warning on !memcg after readahead page > charged") added the warning in folio_lruvec (older name was > mem_cgroup_page_lruvec) for !memcg when charging of readahead pages were > added to the kernel. Basically lru pages on a memcg enabled system were > always expected to be charged to a memcg. > > However a recent functionality to allow metadata of btrfs, which is in > page cache, to be uncharged is added to the kernel. We can either change > the condition to only check anon pages or file pages which does not have > AS_UNCHARGED in their mapping. Instead of such complicated check, let's > just remove the warning as it is not really helpful anymore. This has to go before patch 3 (and I'd put it before patch 1) in order to preserve bisectability.. That requires changing the tenses in the commit message, but that's perfectly acceptable.