From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id EE951C7EE26 for ; Mon, 22 May 2023 14:29:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233055AbjEVO3c (ORCPT ); Mon, 22 May 2023 10:29:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55000 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232856AbjEVO3a (ORCPT ); Mon, 22 May 2023 10:29:30 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4046AAF; Mon, 22 May 2023 07:29:25 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id AF03561DC1; Mon, 22 May 2023 14:29:24 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 996E4C433D2; Mon, 22 May 2023 14:29:22 +0000 (UTC) Date: Mon, 22 May 2023 10:29:20 -0400 From: Steven Rostedt To: David Howells Cc: Jens Axboe , Al Viro , Christoph Hellwig , Matthew Wilcox , Jan Kara , Jeff Layton , David Hildenbrand , Jason Gunthorpe , Logan Gunthorpe , Hillf Danton , Christian Brauner , Linus Torvalds , linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Christoph Hellwig , Masami Hiramatsu , linux-trace-kernel@vger.kernel.org Subject: Re: [PATCH v20 23/32] splice: Convert trace/seq to use direct_splice_read() Message-ID: <20230522102920.0528d821@rorschach.local.home> In-Reply-To: <20230519074047.1739879-24-dhowells@redhat.com> References: <20230519074047.1739879-1-dhowells@redhat.com> <20230519074047.1739879-24-dhowells@redhat.com> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-trace-kernel@vger.kernel.org On Fri, 19 May 2023 08:40:38 +0100 David Howells wrote: > For the splice from the trace seq buffer, just use direct_splice_read(). > > In the future, something better can probably be done by gifting pages from > seq->buf into the pipe, but that would require changing seq->buf into a > vmap over an array of pages. If you can give me a POC of what needs to be done, I could possibly implement it. > > Signed-off-by: David Howells > cc: Christoph Hellwig > cc: Al Viro > cc: Jens Axboe > cc: Steven Rostedt > cc: Masami Hiramatsu > cc: linux-kernel@vger.kernel.org > cc: linux-trace-kernel@vger.kernel.org > cc: linux-fsdevel@vger.kernel.org > cc: linux-block@vger.kernel.org > cc: linux-mm@kvack.org > --- > kernel/trace/trace.c | 2 +- Acked-by: Steven Rostedt (Google) -- Steve > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c > index ebc59781456a..b664020efcb7 100644 > --- a/kernel/trace/trace.c > +++ b/kernel/trace/trace.c > @@ -5171,7 +5171,7 @@ static const struct file_operations tracing_fops = { > .open = tracing_open, > .read = seq_read, > .read_iter = seq_read_iter, > - .splice_read = generic_file_splice_read, > + .splice_read = direct_splice_read, > .write = tracing_write_stub, > .llseek = tracing_lseek, > .release = tracing_release,