From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-qv1-f48.google.com (mail-qv1-f48.google.com [209.85.219.48]) (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 C267C14293 for ; Tue, 12 Mar 2024 22:50:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.219.48 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710283855; cv=none; b=F9HrGUvyZgXVEq8BBGlQRwOTBhkarK1CXivRG6tphtr8iPobSRD+CxTV6SZWoVMDbvVAAykIXwlFXDYhu2d9u3zG+w5zmILWqcvXFX+tbkC8KQoz+PouoxUm+LtFsEn4WDdPbN51juYyWL7W2K20TA4C1CXTDGe/IhMHeF1WKEs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710283855; c=relaxed/simple; bh=PclF/O7qYfyEhrocuRXf1lPkupqWeJw3/nVH9ngyx+Q=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=MkJ5Xta0vHfYykLyhY/ZuGjCy7w1OJOsiRP9RBuwBKzc6Qw+eroq+akmJ8tuq/EKFF93SoKE1uib1ZJMEPQvNxbI0WZmh1koSxKtnIvk15/6fF2j3GWqPw4uFAmTj1QhinHRRHkX2HLNKnxzLxguQMDU+m/MyFDCxy8NWpPlz2o= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org; spf=pass smtp.mailfrom=redhat.com; arc=none smtp.client-ip=209.85.219.48 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Received: by mail-qv1-f48.google.com with SMTP id 6a1803df08f44-690db6edb2bso12107266d6.2 for ; Tue, 12 Mar 2024 15:50:53 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1710283853; x=1710888653; h=in-reply-to:content-transfer-encoding:content-disposition :mime-version:references:message-id:subject:cc:to:from:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=ZlxA4zN3+sPNzBs+kJr4+RA0UafItZ85NKafakxbxd0=; b=WgPkEALrCXtOUc6d4VBULg9zhHKntY4Ag1i6f/rLQX4PXurd+GvgGcXnG4Y3zsvcyY N+T/Bunp07ohbYgPNWdblVqIc0rEphbVynf51qIcXcNMCh2raGv3s/deDHGOPky3+xW6 eMmzgUSW62A2jCwTnC8+kYcSRWubAHE6BaiqFpUK5hRadVNiblQjTv9OK6sVue7iY4kp u3xXOg4kwBX4cWTzwVcPfS+ggb+Cu1HAx7Z21A0i99l4vpDIhcJOFXfU786szEwZU0iq RmMBob9x9/wYP56s8I7EOTxyRCvLm6HE+1tDaTN3uPno0MnGC4iuQm2RGAU0IAITSK4d fAmQ== X-Forwarded-Encrypted: i=1; AJvYcCXz9oOfzsLx0asaz4GxHt/9585e2rFng60XLLRfIihe5+BYAR7fiiczkwABFjPOSe9sYyUpTmJQtQTny5BRpUbLhjRY8/CfaIcAk0k= X-Gm-Message-State: AOJu0YzHLdwoqPXMNJwwBOqjZdvg0RNU2sdUYytRekqD35qNZI4pjaJr QewbxDnVLI4Bu/iEScCs3NMMrqw2Rw0gzZoIHkj0e1J4oRgw0OF0jdcFBJeBzA== X-Google-Smtp-Source: AGHT+IFz7w4TCcQF6u/QupyyFnA/rCjGWz5BrtrrQZTJ0gJN/jUF5dV2aDeDiPowvgueTOaPJ0/eQA== X-Received: by 2002:a05:6214:1764:b0:690:a77d:b6d4 with SMTP id et4-20020a056214176400b00690a77db6d4mr11454505qvb.56.1710283852813; Tue, 12 Mar 2024 15:50:52 -0700 (PDT) Received: from localhost (pool-68-160-141-91.bstnma.fios.verizon.net. [68.160.141.91]) by smtp.gmail.com with ESMTPSA id v12-20020a0ce1cc000000b0068f8a21a065sm4073634qvl.13.2024.03.12.15.50.52 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 12 Mar 2024 15:50:52 -0700 (PDT) Date: Tue, 12 Mar 2024 18:50:51 -0400 From: Mike Snitzer To: Christoph Hellwig Cc: Linus Torvalds , Jens Axboe , Johannes Weiner , "linux-block@vger.kernel.org" , dm-devel@lists.linux.dev Subject: Re: [GIT PULL] Block updates for 6.9-rc1 Message-ID: References: <20240311235023.GA1205@cmpxchg.org> Precedence: bulk X-Mailing-List: linux-block@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: On Tue, Mar 12 2024 at 6:30P -0400, Christoph Hellwig wrote: > On Tue, Mar 12, 2024 at 06:22:21PM -0400, Mike Snitzer wrote: > > > The real problem is that we combine the limits while we shouldn't. > > > Every since we've supported immutable biovecs and do the splitting > > > down in blk-mq there is no point to even inherit such limits in the > > > upper drivers. > > > > immutable biovecs, late splitting and blk-mq aren't a factor. > > > > dm-crypt has to contend with the crypto subsystem and HW crypto > > engines that have their own constraints. > > Yes, they are. The limit for underlying device does not matter for > an upper devіce as it will split later. And that's not just my > opinion, you also clearly stated that in the commit adding the > limits (586b286b110e94e). We should have stopped inheriting all > these limits only relevant for splitting when we switched to > immutable bvecs. I don't know why we didn't, but a big part of > that might be that we never made clear which limits these are. Wow, using my 8+ year old commit message against me ;) I've honestly paged most of this out but I'll revisit, likely with Mikulas, to pin this down better and then see what possible.