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 CD4DAC32772 for ; Tue, 23 Aug 2022 19:38:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232591AbiHWTiG (ORCPT ); Tue, 23 Aug 2022 15:38:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59272 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230394AbiHWThd (ORCPT ); Tue, 23 Aug 2022 15:37:33 -0400 Received: from mail-pj1-x102b.google.com (mail-pj1-x102b.google.com [IPv6:2607:f8b0:4864:20::102b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9BEADA262F; Tue, 23 Aug 2022 11:34:13 -0700 (PDT) Received: by mail-pj1-x102b.google.com with SMTP id pm13so5850080pjb.5; Tue, 23 Aug 2022 11:34:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:sender:from:to:cc; bh=JfIVW5EAwcziVt6ePzGMkVRPbB2bi7yV+a8QRJJ7RgI=; b=q2ExPiLlmr3rFwyGKyFXlMV0seXxl2bOW/vbx0cJKPMa41O8h0U5Zh4IcGSH/ZVlfA tGxkmod7yD4lDznK3zTaxdLioXjnbXJuP5pTi8fvgtB4XP0Zw1RAjUNS19hYVgSqLprg Iu5kjJ4wOVLnNfmSZ0WYps4ZaILOqbrjOz6ENcqZ7z4BF23tEAPFkIJJGqJJsb65I4jL dWoWCcSPW5Xk+5pn15qtd/aOLzGUSPf4kzTDKOvcbryapOxCZResD/Jw7kbtaancyk97 7zU6ZDOeKvDffRu3TqYryVn6skyhNVDmt5NIj8EC1ejkiew4bYHycaz+J/mb1mEpmwzf oVCA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:sender:x-gm-message-state:from:to:cc; bh=JfIVW5EAwcziVt6ePzGMkVRPbB2bi7yV+a8QRJJ7RgI=; b=4VFXlO7ok755vA880UDygPrPPp0tUIZnBtTposDz5dRTHzmYwGBVrRH07RUMDFgQEQ Mn4R54u5BEFfpjHQ+OvcKb7PxA6RKOckk+D43yfeBLA6O77YYu6lRyv6+OFnqm+dpYe5 eVBV/KnfG7VAoIJxd5g+YC3H6AgRCqmq03iGNOQ0nagjqY5vQ4OCIxCyVNBflKNIh/XG OHAGlEOwGMXy8JlDzJLmKpNT9KBFdoaXhE/5uyMpOBqf6OfSfeEgDMCi+Wgk+UR0B0Z+ jWjh5CIYAeXxElSUVwCYu4uu8TF/f3EvBD7p8uC2qNRS2UJ36Ij+dSrmOkwfTTls1x2D u8DQ== X-Gm-Message-State: ACgBeo2rKeYRX4ccLgZ3YeBeNqUP7kkPNDGANel6MjTngLJTFJuzZGar oUTWSiqDAIKLLHAa15jjvgQ= X-Google-Smtp-Source: AA6agR4k77gYNs28ebZLcJfF5hB6Kw5jzDg+UqpjOg+Arvubt7GuKXOlWpjHjwYiz7G1YBG3pgwA+g== X-Received: by 2002:a17:902:6bc9:b0:173:f3f:4a8c with SMTP id m9-20020a1709026bc900b001730f3f4a8cmr1401690plt.96.1661279652870; Tue, 23 Aug 2022 11:34:12 -0700 (PDT) Received: from localhost ([2620:10d:c090:400::5:90fa]) by smtp.gmail.com with ESMTPSA id d131-20020a621d89000000b0050dc76281e0sm11011205pfd.186.2022.08.23.11.34.11 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 23 Aug 2022 11:34:12 -0700 (PDT) Sender: Tejun Heo Date: Tue, 23 Aug 2022 08:34:10 -1000 From: Tejun Heo To: Yu Kuai Cc: axboe@kernel.dk, cgroups@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, yukuai3@huawei.com, yi.zhang@huawei.com Subject: Re: [PATCH 4/4] blk-throttle: cleanup throtl_dequeue_tg() Message-ID: References: <20220823013810.406075-1-yukuai1@huaweicloud.com> <20220823013810.406075-5-yukuai1@huaweicloud.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220823013810.406075-5-yukuai1@huaweicloud.com> Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Tue, Aug 23, 2022 at 09:38:10AM +0800, Yu Kuai wrote: > From: Yu Kuai > > Now that throtl_dequeue_tg() is called when the last bio is dispatched, > there is no need to check the flag THROTL_TG_PENDING, since it's ensured > to be set when bio is throttled. > > There are no functional changes. > > Signed-off-by: Yu Kuai > --- > block/blk-throttle.c | 11 ++++------- > 1 file changed, 4 insertions(+), 7 deletions(-) > > diff --git a/block/blk-throttle.c b/block/blk-throttle.c > index 47142a1dd102..e47506a8ef47 100644 > --- a/block/blk-throttle.c > +++ b/block/blk-throttle.c > @@ -570,14 +570,11 @@ static void throtl_enqueue_tg(struct throtl_grp *tg) > > static void throtl_dequeue_tg(struct throtl_grp *tg) > { > - if (tg->flags & THROTL_TG_PENDING) { > - struct throtl_service_queue *parent_sq = > - tg->service_queue.parent_sq; > + struct throtl_service_queue *parent_sq = tg->service_queue.parent_sq; > > - throtl_rb_erase(&tg->rb_node, parent_sq); > - --parent_sq->nr_pending; > - tg->flags &= ~THROTL_TG_PENDING; > - } > + throtl_rb_erase(&tg->rb_node, parent_sq); > + --parent_sq->nr_pending; > + tg->flags &= ~THROTL_TG_PENDING; Yeah, I don't know about this one. This breaks the symmetry with throtl_enqueue_tg() and it's a bit odd that we aren't at least WARN_ON_ONCE() on the flag given what the flag tracks. If you want to do this, I think the prev approach of just removing the flag is better as that was symmetric at least. Thanks. -- tejun