From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ej1-f45.google.com (mail-ej1-f45.google.com [209.85.218.45]) (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 8B41217BB18 for ; Wed, 10 Jul 2024 08:56:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.218.45 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720601798; cv=none; b=O4d8W70aQWqrAPHTevUr6EbguBOfWCMlVzC9aNHPiSiyScd0Vyl+wvdPArZJO+luY0Jf0QBEh4SolO77gnoMsTDYe+6thgTX6neHBcpr//q7R/jGBln92Ali9Yqgx5XsYi0GyvjojTSShDIuLEuOKPOxwsoDN6SKiYIwfcYkUoA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720601798; c=relaxed/simple; bh=9/rX9rvb1Z1XmLlY4faa9AJZN3iaOMzGyDvAwevHP7I=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=soq5jK1emGTil3V2YsGxGsN3pHX7TYTlIn7OlQ0kJM4+2svSp4FCvXmYFRwKpY/KSXEURHRbWNVikQgTDkDl6T35MV1FlGA/7ipCFELE5CrkHKNyf7gfcWZBGCx+NCAKrP3+Fd2FLLCTWu4Z9K7NYKRwLZ5r4HQOKJL+/07q7cw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=Ch0N2TPT; arc=none smtp.client-ip=209.85.218.45 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Ch0N2TPT" Received: by mail-ej1-f45.google.com with SMTP id a640c23a62f3a-a77d85f7fa3so89096366b.0 for ; Wed, 10 Jul 2024 01:56:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1720601795; x=1721206595; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=YYny+C18uFNOCEmpysA9wjgrbs4B3jH8zjB4KcPnhHg=; b=Ch0N2TPT6TG1/CJSiozEAtNXbp91DOQ6nTB6NAGq4oLc8ZXLCZ/lONQ9o6Gp/IwdIE hF7j5VjKvXwSRGXXniwSXFIRn0LDx1FaP8pY2IjGtdEbKL3q0nteZktUk4kJKwxvEuRm x5krJBOvYbqFvhoHqKVjNJYwzxV0PrA9+TPkB8hLl0C302EkuC0fFwWqYScrCa0P5juN pWuC61JMa6+iGgVg74Febrf68sFhZkyCXJrp7oBI2FIOpVou7s42Hx9FTMjxYvkkKNO8 kN3vO9+XLOHwpS4r1IbnpiuaXC+OBfvpzUAVWTriwK44VJtfSh3c6ON0q5csbqqkdN9x jaxw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1720601795; x=1721206595; h=in-reply-to: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=YYny+C18uFNOCEmpysA9wjgrbs4B3jH8zjB4KcPnhHg=; b=ABF4VbOb7+YBceyUAG/+oUjmA2dSt95AG1LIbzxgQHP3qiqX5WlZ3xt9KGUhxsyoAN u4Y0OVaIYnXvyylHmVdTUAMglvh2bQH6MQRh1NEk0BzgnRGXPmbZHvJXASmrH5e/dsGx iD8ZpF4ZRWCv2UTETadwbsOAuHnRlcWKnwDV6CGqAZzltTI9ZBu6iMrdbobRvASZJujW 4K66f++dk2vLxPWadRV9nUTEe+Wnbp8MPFTj3ev3E7KCUgbaN1U9U5DoAF29lni8mpD0 2s6vSsF+ImCOw1zAtVRp6fHQM41rAu2WIy6IWD433Rv78s/A7WBDfxTdM2Q4xNHvr4CO 57Dw== X-Forwarded-Encrypted: i=1; AJvYcCUL8Io7lcl5iCl5HL01ZeIExq3b0qqpgN0AEa0rV1r3p+R2kuIpYgtBK+z83hKB1RB1Dht1tIf3OPKosYflqTGQVXyJdTQDtx+M+FE9 X-Gm-Message-State: AOJu0YxjwGXGL0VetlcKnUFWk1Q+sN2mHzImEvJk8EqEDF0v9T2TEfRC fNXGlaiphDEEHg+3aOwJaUk7sF+0QWjyuPgkSZLiDaIJ6I/Xk0c= X-Google-Smtp-Source: AGHT+IGmX2ULoy6m40kNtxUUURHBIPSq4gSHfjtVoP3q/J5L5bBlGUSOQr0a4+lbCg17dpPonoLOlw== X-Received: by 2002:a17:906:2451:b0:a77:dba6:346 with SMTP id a640c23a62f3a-a780d28c43fmr293066566b.32.1720601794538; Wed, 10 Jul 2024 01:56:34 -0700 (PDT) Received: from localhost ([151.47.106.45]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-a780a872e0dsm141051066b.215.2024.07.10.01.56.33 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 10 Jul 2024 01:56:34 -0700 (PDT) Date: Wed, 10 Jul 2024 10:56:31 +0200 From: Andrea Righi To: Tejun Heo Cc: void@manifault.com, linux-kernel@vger.kernel.org, kernel-team@meta.com, schatzberg.dan@gmail.com, mingo@redhat.com, peterz@infradead.org, changwoo@igalia.com Subject: Re: [PATCH 2/6] sched_ext: Open-code task_linked_on_dsq() Message-ID: References: <20240709212137.1199269-1-tj@kernel.org> <20240709212137.1199269-3-tj@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@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: <20240709212137.1199269-3-tj@kernel.org> On Tue, Jul 09, 2024 at 11:21:08AM -1000, Tejun Heo wrote: > task_linked_on_dsq() exists as a helper becauase it used to test both the small nit: becauase -> because. > rbtree and list nodes. It now only tests the list node and the list node > will soon be used for something else too. The helper doesn't improve > anything materially and the naming will become confusing. Open-code the list > node testing and remove task_linked_on_dsq() > > Signed-off-by: Tejun Heo > Cc: David Vernet > --- > kernel/sched/ext.c | 11 +++-------- > 1 file changed, 3 insertions(+), 8 deletions(-) > > diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c > index f16d72d72635..52340ac8038f 100644 > --- a/kernel/sched/ext.c > +++ b/kernel/sched/ext.c > @@ -1572,18 +1572,13 @@ static void task_unlink_from_dsq(struct task_struct *p, > list_del_init(&p->scx.dsq_list.node); > } > > -static bool task_linked_on_dsq(struct task_struct *p) > -{ > - return !list_empty(&p->scx.dsq_list.node); > -} > - > static void dispatch_dequeue(struct rq *rq, struct task_struct *p) > { > struct scx_dispatch_q *dsq = p->scx.dsq; > bool is_local = dsq == &rq->scx.local_dsq; > > if (!dsq) { > - WARN_ON_ONCE(task_linked_on_dsq(p)); > + WARN_ON_ONCE(!list_empty(&p->scx.dsq_list.node)); > /* > * When dispatching directly from the BPF scheduler to a local > * DSQ, the task isn't associated with any DSQ but > @@ -1604,7 +1599,7 @@ static void dispatch_dequeue(struct rq *rq, struct task_struct *p) > */ > if (p->scx.holding_cpu < 0) { > /* @p must still be on @dsq, dequeue */ > - WARN_ON_ONCE(!task_linked_on_dsq(p)); > + WARN_ON_ONCE(list_empty(&p->scx.dsq_list.node)); > task_unlink_from_dsq(p, dsq); > dsq_mod_nr(dsq, -1); > } else { > @@ -1614,7 +1609,7 @@ static void dispatch_dequeue(struct rq *rq, struct task_struct *p) > * holding_cpu which tells dispatch_to_local_dsq() that it lost > * the race. > */ > - WARN_ON_ONCE(task_linked_on_dsq(p)); > + WARN_ON_ONCE(!list_empty(&p->scx.dsq_list.node)); > p->scx.holding_cpu = -1; > } > p->scx.dsq = NULL; > -- > 2.45.2