From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 BBD1A206F04; Wed, 19 Mar 2025 08:04:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.133 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742371493; cv=none; b=NOBeM/2has9Gq69ZmWiTEP5fss/FXnwXHPWqzL4033Y3wNKnn1+1sqDOkt9EtsewzhfZ/HJTrmoZO/M1HbIDkECnJLPWmVoNWKuPyupC06yf+SykjWhW7g+tlQdU4wk8ic3JQ2+kklKIhLJX8NjgyVWMwFvXooXSTcTu0M3vap4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742371493; c=relaxed/simple; bh=FSNFV5aiawfVEPuMK3UBCZZb3/nWmzSnJzh+8OKYIrk=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=p5UNZfX3Davbj33OJihXvKkCurGXSDpkdPYpZLhzQ8RfExo+/mMtaaQAafByh1sS3e1wl59ZEAmaZgboKd7/RfM+gG4VmUvv1cmsRjlNWnwhyTE8FJUxbtI12039lLfdYaP1yr3GjhSsDizyHijftQyKnYWZuSXpvmip2egV4VI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=2IwkNzvV; arc=none smtp.client-ip=198.137.202.133 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=bombadil.srs.infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="2IwkNzvV" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; 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=FSNFV5aiawfVEPuMK3UBCZZb3/nWmzSnJzh+8OKYIrk=; b=2IwkNzvVlrZXNwyCeTEPJQ8F07 mHBnaZm+2SYzj9yte8H+h4ugukyHaooQN44YZ5VaYs/3ou0ePckDXk74CwhuRgUqJuOEPMfF6iUDe hQcdu6v22lTgEkab4Iq6naRWcxrNTluRM+NprIS7DRr0K8wcCDfiM/OR9YYYL4flt14X9gs8tVHON anS8xHd3sCoM8QzTE9EC30hBSL7mM7IG+1kla2ZQFM5VNpzj6JCVcSNivw+5a2PlLbRmVqasI3wrH w9n+03TD5fFP8m+W6G2FuB3u4cNsXCeDEjRFy5YwdefmTPW/57pJqwp9vqByYtsQToDwsMDe5Qz0v YcjedCWg==; Received: from hch by bombadil.infradead.org with local (Exim 4.98 #2 (Red Hat Linux)) id 1tuoPw-00000008IXM-33MY; Wed, 19 Mar 2025 08:04:48 +0000 Date: Wed, 19 Mar 2025 01:04:48 -0700 From: Christoph Hellwig To: Joe Damato Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, asml.silence@gmail.com, linux-fsdevel@vger.kernel.org, edumazet@google.com, pabeni@redhat.com, horms@kernel.org, linux-api@vger.kernel.org, linux-arch@vger.kernel.org, viro@zeniv.linux.org.uk, jack@suse.cz, kuba@kernel.org, shuah@kernel.org, sdf@fomichev.me, mingo@redhat.com, arnd@arndb.de, brauner@kernel.org, akpm@linux-foundation.org, tglx@linutronix.de, jolsa@kernel.org, linux-kselftest@vger.kernel.org Subject: Re: [RFC -next 00/10] Add ZC notifications to splice and sendfile Message-ID: References: <20250319001521.53249-1-jdamato@fastly.com> Precedence: bulk X-Mailing-List: linux-api@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: <20250319001521.53249-1-jdamato@fastly.com> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html On Wed, Mar 19, 2025 at 12:15:11AM +0000, Joe Damato wrote: > One way to fix this is to add zerocopy notifications to sendfile similar > to how MSG_ZEROCOPY works with sendmsg. This is possible thanks to the > extensive work done by Pavel [1]. What is a "zerocopy notification" and why aren't you simply plugging this into io_uring and generate a CQE so that it works like all other asynchronous operations?