From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-170.mta0.migadu.com (out-170.mta0.migadu.com [91.218.175.170]) (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 C06DB3E8677 for ; Tue, 17 Mar 2026 14:39:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.170 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773758344; cv=none; b=rEvk/ra0YEFt1KauecUle1Ti4SszLJc1RkhIFXr/PR5Yp1CN/eZ8SfVSNvW26Iwp+1xT0mHZgTB+8FtTDWLvIVHljpstwJv2++4dGKGDPeVab5DapN/1xOG/MjKkMcvTOPpty6Zs0Z/ip25aryH4D73Z3KCFphUCpKSRC3lwinU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773758344; c=relaxed/simple; bh=A147bc2bT4KeYZIRrgqu8fITAQVo9jfiIw91PSZaPR0=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=CZ+oqh5AtXh8WLwXqgWqLwep+mxVFlVy5TI4NI/zLuPoVcm50HnuqUL6MVIHo0wtZIq2WoE0bGqOsnV1O5BUBmEmPjlpyI18VD8Wr87so+Z5YTYibaXsHAQl77IVS9n9qBCmZJzCDPhmVcgZssDQbb1HuR8b+mDTeOGAPPSluNA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=k6Sjz6TS; arc=none smtp.client-ip=91.218.175.170 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="k6Sjz6TS" Message-ID: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1773758340; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=63wRMo0FngaKINvt5+DIgmP+fsqgLbRaWZ8w/1faLk8=; b=k6Sjz6TSdC2nyKK9J9E+a8l366kISxnRJfdxzpVkQlPVTK/IWd0VPDIiPnVsblmcjLK10M ys1G65d5PpN3bhe92/K0dHRc7WJ3ElveCMa+WXW46uw/+EDJ0YYyeagk0so/h4qtEXG8Bt 4EP6xNeD+esG33CS6wCEbQVw2N/Z72g= Date: Tue, 17 Mar 2026 07:38:49 -0700 Precedence: bulk X-Mailing-List: linux-rdma@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [PATCH] RDMA/rxe: Replace use of system_unbound_wq with system_dfl_wq To: Leon Romanovsky , Marco Crivellari , "yanjun.zhu@linux.dev" Cc: linux-kernel@vger.kernel.org, linux-rdma@vger.kernel.org, Tejun Heo , Lai Jiangshan , Frederic Weisbecker , Sebastian Andrzej Siewior , Michal Hocko , Zhu Yanjun , Jason Gunthorpe References: <20260313154023.298325-1-marco.crivellari@suse.com> <20260316201301.GL61385@unreal> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Zhu Yanjun In-Reply-To: <20260316201301.GL61385@unreal> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT 在 2026/3/16 13:13, Leon Romanovsky 写道: > On Fri, Mar 13, 2026 at 04:40:23PM +0100, Marco Crivellari wrote: >> This patch continues the effort to refactor workqueue APIs, which has begun >> with the changes introducing new workqueues and a new alloc_workqueue flag: >> >> commit 128ea9f6ccfb ("workqueue: Add system_percpu_wq and system_dfl_wq") >> commit 930c2ea566af ("workqueue: Add new WQ_PERCPU flag") >> >> The point of the refactoring is to eventually alter the default behavior of >> workqueues to become unbound by default so that their workload placement is >> optimized by the scheduler. >> >> Before that to happen, workqueue users must be converted to the better named >> new workqueues with no intended behaviour changes: >> >> system_wq -> system_percpu_wq >> system_unbound_wq -> system_dfl_wq >> >> This way the old obsolete workqueues (system_wq, system_unbound_wq) can be >> removed in the future. > > I recall earlier efforts to replace system workqueues with per‑driver queues, > because unloading a driver forces a flush of the entire system workqueue, > which is undesirable for overall system behavior. > > Wouldn't it be better to introduce a local workqueue here and use that instead? Thanks. 1.The initialization should be: my_wq = alloc_workqueue("my_driver_queue", WQ_UNBOUND | WQ_MEM_RECLAIM, 0); if (!my_wq) return -ENOMEM; 2. The Submission should be: queue_work(my_wq, &my_work); 3. Destroy should be: destroy_workqueue() Thanks, Zhu Yanjun > > Thanks > >> >> Link: https://lore.kernel.org/all/20250221112003.1dSuoGyc@linutronix.de/ >> Suggested-by: Tejun Heo >> Signed-off-by: Marco Crivellari >> --- >> drivers/infiniband/sw/rxe/rxe_odp.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/drivers/infiniband/sw/rxe/rxe_odp.c b/drivers/infiniband/sw/rxe/rxe_odp.c >> index bc11b1ec59ac..d440c8cbaea5 100644 >> --- a/drivers/infiniband/sw/rxe/rxe_odp.c >> +++ b/drivers/infiniband/sw/rxe/rxe_odp.c >> @@ -545,7 +545,7 @@ static int rxe_ib_advise_mr_prefetch(struct ib_pd *ibpd, >> work->frags[i].mr = mr; >> } >> >> - queue_work(system_unbound_wq, &work->work); >> + queue_work(system_dfl_wq, &work->work); >> >> return 0; >> >> -- >> 2.53.0 >>