From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mta0.migadu.com (out-36.mta0.migadu.com [91.218.175.36]) (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 EF7D43B059F for ; Thu, 10 Sep 2026 08:33:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.36 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789029204; cv=none; b=oaSt2E7PsDhxQvHapOfbvABI+yRA0YT/y33feFTevaoSsqrwvbXDFYoDoLykMd4oJCE2wNNTDxo07SGFR0NalvB3MgJDu5uV1evDf/3PqRl/SNdbRk/Q/VhunFr5lGGrig0QEm8yYITQN4xyYz6oPKRlfwQZVUmdB9EneL57OLI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789029204; c=relaxed/simple; bh=3Q0TgDX5uuy2JzuGxiyBfj3XV6sc+FicZjZ2PsgT9iA=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=oBYJdJW5RHUsHnD5SQYrHq41HqF5zPnjjxvRHKS/bDOVk6aY9ijGvNaPrMIaq2/62xy9DqizzBW1Tux4WRJEIT/vzXX8FQCb1PigP+ciHDB1+Y0tSTjhVWI907N1csbECYH/VBsCKNOrGNJAukpHceEUvS9RkHC+o6xDpxwgqyA= 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=dlMEsINH; arc=none smtp.client-ip=91.218.175.36 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="dlMEsINH" X-Envelope-To: linux-kernel@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=3Q0TgDX5uuy2JzuGxiyBfj3XV6sc+FicZjZ2PsgT9iA=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1789029200; v=1; x=1789634000; b=dlMEsINHZwypgnFShrI+yt5i41aBDhZIMKKLfErpBBunE2/Ef32atqmRrTn0ID7GZi8y26+f boTvfKbv/aRjrBK5+CfJn2h9zrMH+U6iCYiaoXnsxbkWvuSgJS9LnLBSSsYZdxu0GK1dexnNu6q E6bjoM3mbugkcBxHfAvBxOTM= X-Envelope-To: linux-kernel@vger.kernel.org Received: by smtp.migadu.com with ESMTPS id d2b225be2d1f5814; Thu, 10 Sep 2026 08:33:10 +0000 X-Mizu-Trace-ID: d2b225be2d1f5814 X-Migadu-Flow: FLOW_OUT Message-ID: Date: Thu, 10 Sep 2026 16:33:06 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH RESEND] mm/vmalloc: Use dedicated unbound workqueues for vmap drain To: "Uladzislau Rezki (Sony)" , linux-mm@kvack.org, Andrew Morton Cc: Baoquan He , LKML , stable@vger.kernel.org, Dev Jain , lirongqing References: <20260905152717.11711-1-urezki@gmail.com> Content-Language: en-US From: Ye Liu In-Reply-To: <20260905152717.11711-1-urezki@gmail.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 在 2026/9/5 23:27, Uladzislau Rezki (Sony) 写道: > drain_vmap_area_work() function can take >10ms to complete > when there are many accumulated vmap areas in a system with > high CPU count, causing workqueue watchdog warnings when run > via schedule_work(): > > workqueue: drain_vmap_area_work hogged CPU for >10000us > > Move the top-level drain work to a dedicated WQ_UNBOUND > workqueue so the scheduler can run this background work > on any available CPU, improving responsiveness. Use the > WQ_MEM_RECLAIM to ensure forward progress under memory > pressure. > > Move purge helpers to separate WQ_UNBOUND | WQ_MEM_RECLAIM > workqueue. This allows drain_vmap_work to wait for helpers > completion without creating dependency on the same rescuer > thread and avoid a potential parent/child deadlock. > > Simplify purge helper scheduling by removing cpumask-based > iteration to iterating directly over vmap nodes checking > work_queued state. > > Cc: stable@vger.kernel.org > Cc: Dev Jain > Cc: Ye Liu > Cc: lirongqing > Fixes: 72210662c5a2 ("mm: vmalloc: offload free_vmap_area_lock lock") > Link: https://lore.kernel.org/all/20260319074307.2325-1-lirongqing@baidu.com/ > Reviewed-by: Baoquan He > Signed-off-by: Uladzislau Rezki (Sony) Reviewed-by: Ye Liu -- Thanks, Ye Liu