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 X-Spam-Level: X-Spam-Status: No, score=-18.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1DBDAC43214 for ; Fri, 20 Aug 2021 12:21:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0626660F45 for ; Fri, 20 Aug 2021 12:21:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240540AbhHTMVv (ORCPT ); Fri, 20 Aug 2021 08:21:51 -0400 Received: from mail.kernel.org ([198.145.29.99]:34338 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240526AbhHTMVq (ORCPT ); Fri, 20 Aug 2021 08:21:46 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 80C2860FE6; Fri, 20 Aug 2021 12:21:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1629462068; bh=XokPNaEZzCBVxZsGy8OxFfqbu3eCtU/5yezA3ayFAVE=; h=Date:From:To:cc:Subject:In-Reply-To:References:From; b=fuaiNjmrqEGqEyZ0Td9kJzBEOFdZR1XtiyRqYRBAUQ6cgnwHen8DbRX1WbhDLK4sp fg6t0e/X0bIo6ghCAbHQ4q9OnJheCUDkzcUXuEFzkjQbx7hyOFhjM3lw9N6R5DZwwS RyuV/ZootL/25yfGBgx2+OonSLAzV6yuay+Z3AVYD4HFCoa52ip+zot/jdv5hL4C7p dOGRUroa2bfHf/xlXOQ8bsqpH9YjwyfQh+vNORkDGJKXNiUGtcf6gH/+MOD7xXJ3LJ glioz7ThqLAz2ypXdFWdGdlgCir6VygZ51YKIjoDkcFcvv0Hb+X7dpqXcSR+4mkVDj TO2qcKyKmczKQ== Date: Fri, 20 Aug 2021 14:21:05 +0200 (CEST) From: Jiri Kosina To: Christophe JAILLET cc: benjamin.tissoires@redhat.com, linux-input@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org Subject: Re: [PATCH] HID: logitech-hidpp: Use 'atomic_inc_return' instead of hand-writing it In-Reply-To: <1091bc38881086be28d561adca042caba234f3f2.1627054657.git.christophe.jaillet@wanadoo.fr> Message-ID: References: <1091bc38881086be28d561adca042caba234f3f2.1627054657.git.christophe.jaillet@wanadoo.fr> User-Agent: Alpine 2.21 (LSU 202 2017-01-01) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 23 Jul 2021, Christophe JAILLET wrote: > This function logs a warning if the workqueue gets too big. > In order to save a few cycles, use 'atomic_inc_return()' instead of an > 'atomic_inc()/atomic_read()' sequence. > > This axes a line of code and saves a 'atomic_read()' call. > > Signed-off-by: Christophe JAILLET > --- > drivers/hid/hid-logitech-hidpp.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff --git a/drivers/hid/hid-logitech-hidpp.c b/drivers/hid/hid-logitech-hidpp.c > index 61635e629469..a7fa35245c2e 100644 > --- a/drivers/hid/hid-logitech-hidpp.c > +++ b/drivers/hid/hid-logitech-hidpp.c > @@ -2240,11 +2240,10 @@ static int hidpp_ff_queue_work(struct hidpp_ff_private_data *data, int effect_id > wd->size = size; > memcpy(wd->params, params, size); > > - atomic_inc(&data->workqueue_size); > + s = atomic_inc_return(&data->workqueue_size); > queue_work(data->wq, &wd->work); > > /* warn about excessive queue size */ > - s = atomic_read(&data->workqueue_size); > if (s >= 20 && s % 20 == 0) > hid_warn(data->hidpp->hid_dev, "Force feedback command queue contains %d commands, causing substantial delays!", s); Applied, thank you. -- Jiri Kosina SUSE Labs