From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 1415854EEBC; Tue, 8 Sep 2026 16:21:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788884514; cv=none; b=stYCkcKZUPzSWyVOx7WBOKxw2+OuKwZd/rM8rbNbiQGEPtSlOSzW9DSMPTF1NqWtnvz4fQrhKU1ZFqCSXO6npqxCG6qyBdwp6RBR5wl714h0rgRNREjLYsTj7I1WQk3AbBGGQOr9WuAPtLfPRP6Bi0Rixgocl8Fpq0F2DeLjIYM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788884514; c=relaxed/simple; bh=FlVZhIe8XWeo2xdg+2N8/HN5+zcTxL3Nv/ReOPyjFRs=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=KhuCketD8PbxzEZXHt/+dENX7YQTlYJ6cW7ClnDQFsoTa59FXyzKl91QpA+o5xL3reJPakL6kZdFIvLaBHSsDyoO/IoTCC7muw+QFxBAROCT0TtQ3QQ1E3TjPrdi1YM1IeQyKPwg1T2u8ETbGu8bpqET+lDjLTrs+mp6lOZr+RE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=JiZa1FAG; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="JiZa1FAG" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 123031F00A3A; Tue, 8 Sep 2026 16:21:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788884512; bh=7TqmDJUy5o6mpDI4ISF8yh2oVfrhqIccw/xxHz+n0OU=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=JiZa1FAGRjiBxr4eCE7etd8xF5Ox2fvunf4Jh+pFg1WAlP4CubwSmpW8U6vTnZbqI YPq9gfVGk9OeA9lPeUUItoILDjtrvzuNLB1QRZzdMNroVNsqitDi63hRXYHDWz8faX ryQ4NCpeoWxNaIWCwerL0PlpSURsC79JZceJ11MmTMhmAQPP9fUSqHbOMpekl2pkdx jgPUXw+/QOFPPU4n9pXbY5TmblnOwnS2K0Y1UVizacnB1rHu1w//n5XlgfEoru/2O7 pCEWvLm7W9BGee4uNRUQoDTIiJNIonPu9E1BUPZULWOxY3pMWs2zt/FjbDlFGfVudH /BwFmrRFqP37A== Message-ID: <25144cf6-a5ae-4e1f-b77b-768e2636825f@kernel.org> Date: Tue, 8 Sep 2026 18:21:43 +0200 Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 02/25] mm/fbatch: allow folios_put_refs() to skip xa_is_value() entries Content-Language: en-US To: Hugh Dickins , Andrew Morton Cc: Ackerley Tng , Alexander Viro , Baolin Wang , Barry Song , Binbin Wu , Christian Brauner , Christoph Hellwig , Christoph Lameter , Claudio Imbrenda , David Hildenbrand , JP Kobryn , Jan Kara , Johannes Weiner , Kairui Song , Kiryl Shutsemau , Lance Yang , Leonardo Bras , Lorenzo Stoakes , Marcelo Tosatti , Matthew Wilcox , Mel Gorman , Miaohe Lin , Michal Hocko , Minchan Kim , Muchun Song , Oscar Salvador , Peter Zijlstra , Qi Zheng , Rik van Riel , Sebastian Andrzej Siewior , Shakeel Butt , Suren Baghdasaryan , Yang Shi , Yu Zhao , Zach O'Keefe , Zi Yan , linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org References: <14a16945-529b-8bc0-ab38-3ea97e54e223@google.com> <44c7773e-5806-d24a-83c9-f39b3a134138@google.com> From: "Vlastimil Babka (SUSE)" Autocrypt: addr=vbabka@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit On 8/24/26 15:55, Hugh Dickins wrote: > Let folios_put_refs() (hence folio_batch_release()) skip xa_is_value() > entries, and therefore remove unneeded folio_batch_remove_exceptionals(). > > It made some sense when introduced in 3.1 for shmem swap entries only, > but workingset shadows popularized exceptional entries in 3.15, and it's > silly for so many sites to be squashing exceptionals out of the fbatch, > merely to suit an inadequacy in folios_put_refs(). > > But remove exceptionals on leaving truncate_folio_batch_exceptionals(), > one of whose callers then passes the fbatch on to others less tolerant. > > No longer essential to this series, since 7.2 commit 9669b87065a6 > ("mm/lruvec: preemptively free dead folios during lru_add drain") > allowed folios_put_refs() to skip NULLs; but still an improvement. > > Signed-off-by: Hugh Dickins Like David, I don't understand what exactly truncate_folio_batch_exceptionals() does. But this patch seems correct to me, so: Reviewed-by: Vlastimil Babka (SUSE)