From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from stravinsky.debian.org (stravinsky.debian.org [82.195.75.108]) (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 2E082417362; Fri, 3 Jul 2026 15:28:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=82.195.75.108 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783092489; cv=none; b=Qp4FGeOm+z/38m/OxxgV2d/JSr8SMToZfSdN1klgybCikIceJ7FkNGMytb7FGCJgkS++K7dizM4NcymEisAvc7jQ1bFcxcYfYv075z9vA6s0zIzqfuSPDUMSGN0AwoGdXIEMpx/61DE+B61y+gv8fsfohb4F2m4l6qj24JuSkkU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783092489; c=relaxed/simple; bh=lJs+X8K4Cg4WT85592ug9GjWBI+cC7fnH1XJ4xBucWc=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=lvMu96YxE4IH/1ydeKDKbJISLzVBRVzCYtC/bYJi61vRVacXZC4tTmb0bW2b3z7qA534vzi6C1gRvgT3nJaYDcGz34aLpjSt1gtbxkQvgAYsiJ92RieewdrvMAD86x0//lPQb9tFxGbIucO6CmrpNxarO/7U3/E76guKJ+MGjC4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=debian.org; spf=pass smtp.mailfrom=debian.org; dkim=pass (2048-bit key) header.d=debian.org header.i=@debian.org header.b=CLGEWLJ2; arc=none smtp.client-ip=82.195.75.108 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=debian.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=debian.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=debian.org header.i=@debian.org header.b="CLGEWLJ2" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=debian.org; s=smtpauto.stravinsky; h=X-Debian-User:In-Reply-To:Content-Transfer-Encoding: Content-Type:MIME-Version:References:Message-ID:Subject:Cc:To:From:Date: Reply-To:Content-ID:Content-Description; bh=qn6Y0intizxOglKqDr5Ezl5KVx+GFNtYQ6t8bLYOToE=; b=CLGEWLJ2jPJtYSfK+ByNl0XqSb UR1usI+X5v24b5Vyd0XiVyVwpX55Z5GqMeo9RzneOM8C0i15L+bVHBETIXWhFeIqBGdWKlJMNT5SJ hG5L7+1d7VsdsU77ZYaCFFSrQauOnPrZPNHYIbetxFtAO5DKS4o4u+dBiCROCipFn3O+61+R8XIVe QgBWbHqwFsuimb0DfSDQkUCGYSjm6F7/t8hmg5PmGW92xJnfvPfcRDr9wCMlQCXkmHLjTUjAjrv4f fbV6FHBUDQdJ1+KX7dyOpBp8IT1hWA3S8O1weeQIZGGEFYtcejsUwFKREkZUEe12BiiLoFl1Wt+iP 53nmzXBA==; Received: from authenticated-user by stravinsky.debian.org with esmtpsa (TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim 4.96) (envelope-from ) id 1wffo3-009UgM-2E; Fri, 03 Jul 2026 15:27:56 +0000 Date: Fri, 3 Jul 2026 08:27:51 -0700 From: Breno Leitao To: Christian Brauner Cc: Alexander Viro , oleg@redhat.com, mjguzik@gmail.com, josh@joshtriplett.org, Jan Kara , jlayton@kernel.org, axboe@kernel.dk, shakeel.butt@linux.dev, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-team@meta.com Subject: Re: [PATCH RFC 0/4] fs/pipe: unify the page pools into a single per-pipe pool Message-ID: References: <20260626-b4-pipe-unification-v1-0-d23fa6b1ee27@debian.org> <20260703-dutzend-endabrechnung-mensaessen-1e020014ecba@brauner> 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=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20260703-dutzend-endabrechnung-mensaessen-1e020014ecba@brauner> X-Debian-User: leitao Hello Christian, On Fri, Jul 03, 2026 at 12:19:50PM +0200, Christian Brauner wrote: > On 2026-06-26 03:26 -0700, Breno Leitao wrote: > > TL;DR: This simplifies the pipe code, unify the page pools, reduce the > > code by 11 lines, and improves the microbenchmark by up to 23% — so it's > > probably wrong (!?). > > > > Summary: > > ======= > > > > I've spent some time converging tmp_page[] and the on-stack > > anon_pipe_prealloc pool of pages into a single per-pipe pool, as > > discussed previously in a few places, most recently at: > > > > https://lore.kernel.org/all/ajLA_zxsYyKISkwp@redhat.com/ > > I think this makes sense. Sashiko has some comments on missing trim for > readers you might want to consider. Thanks for looking at it. Agreed, we want to trim on the reader side as well, otherwise we might end up with more than 2 (current default) pages in the pipe structure. I will update this RFC and resend as a v2. --breno