From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 05D5C4D9E3; Sun, 24 Mar 2024 22:35:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711319705; cv=none; b=msHSRqlohzZ24PQ10anM6Lukahf/4GCAbT+IosT736BluMBeVMsna4igb23wjqlKGjV5VTCQzBvI4oDRkHQKbPXuh9I8EoRz19XrKWDM12MGOO9qN7jVSWn/6E+cTirf1bgxS11ZD162vHVRj+DRkLsPddTzFfrXmSAxTQbkf0E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711319705; c=relaxed/simple; bh=VNKgCdf+8XLDqyA5oqNOYsgu4Nyq48Fer9bqXElncUQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=EVuyZ5tPjxVZ0iUydL0WxGfTBejyDBVkUOcW6Tk6U19PLSvNDMRTZ9zEdGllMeUmWd35K1mvgBxSKnQF6Clc7tWnos5N+CP8A2bdHo91ZDUR6fQu+rEjhEQKaO/WSCE2+fNVJKxOhGlZpU4MPAcIsm1csZqASdZ1sOHsRgZmK5o= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Pg+dLDYb; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Pg+dLDYb" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EE1E6C43390; Sun, 24 Mar 2024 22:35:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1711319704; bh=VNKgCdf+8XLDqyA5oqNOYsgu4Nyq48Fer9bqXElncUQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Pg+dLDYbWAMz1BG5G6M8A4hcMF2vvphlJJ2x3atYexdIf2bHBEgYuCf24XsVKfIwJ rWPcUW2tFuH3QJ4Yaoc6Xqa27z4VugpPkPYqqxJlzbC4bZLzsIrEY8SGrwKpEmDDV+ OrYh1DEsgFutwnSjAqOwqvE5Dt2tioPTOLDBCxVfRjexN5R32j/mmc6sXBIjGInJ2S Azad9ySTFD73hqo+diEO0fGPQ2Kk+2oatsKrhchPxMjFLZZI7mblKcCmfriHX9B212 ndjcpTfmpjYt2y3tzKtUZvwaTZzS7np3Rzl2BxqwNbN+B9WZkd1Wnc0NNxCXvJ1D+c AWWrkGeWm1RrA== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Tejun Heo , Lai Jiangshan , Sasha Levin Subject: [PATCH 6.8 007/715] workqueue: Make wq_adjust_max_active() round-robin pwqs while activating Date: Sun, 24 Mar 2024 18:23:06 -0400 Message-ID: <20240324223455.1342824-8-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240324223455.1342824-1-sashal@kernel.org> References: <20240324223455.1342824-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit From: Tejun Heo [ Upstream commit c5404d4e6df6faba1007544b5f4e62c7c14416dd ] wq_adjust_max_active() needs to activate work items after max_active is increased. Previously, it did that by visiting each pwq once activating all that could be activated. While this makes sense with per-pwq nr_active, nr_active will be shared across multiple pwqs for unbound wqs. Then, we'd want to round-robin through pwqs to be fairer. In preparation, this patch makes wq_adjust_max_active() round-robin pwqs while activating. While the activation ordering changes, this shouldn't cause user-noticeable behavior changes. Signed-off-by: Tejun Heo Reviewed-by: Lai Jiangshan Stable-dep-of: 5797b1c18919 ("workqueue: Implement system-wide nr_active enforcement for unbound workqueues") Signed-off-by: Sasha Levin --- kernel/workqueue.c | 31 +++++++++++++++++++------------ 1 file changed, 19 insertions(+), 12 deletions(-) diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 80733046ee012..1659cd4a36c62 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -4703,7 +4703,7 @@ static int init_rescuer(struct workqueue_struct *wq) */ static void wq_adjust_max_active(struct workqueue_struct *wq) { - struct pool_workqueue *pwq; + bool activated; lockdep_assert_held(&wq->mutex); @@ -4723,19 +4723,26 @@ static void wq_adjust_max_active(struct workqueue_struct *wq) */ WRITE_ONCE(wq->max_active, wq->saved_max_active); - for_each_pwq(pwq, wq) { - unsigned long flags; - - /* this function can be called during early boot w/ irq disabled */ - raw_spin_lock_irqsave(&pwq->pool->lock, flags); - - while (pwq_activate_first_inactive(pwq)) - ; + /* + * Round-robin through pwq's activating the first inactive work item + * until max_active is filled. + */ + do { + struct pool_workqueue *pwq; - kick_pool(pwq->pool); + activated = false; + for_each_pwq(pwq, wq) { + unsigned long flags; - raw_spin_unlock_irqrestore(&pwq->pool->lock, flags); - } + /* can be called during early boot w/ irq disabled */ + raw_spin_lock_irqsave(&pwq->pool->lock, flags); + if (pwq_activate_first_inactive(pwq)) { + activated = true; + kick_pool(pwq->pool); + } + raw_spin_unlock_irqrestore(&pwq->pool->lock, flags); + } + } while (activated); } __printf(1, 4) -- 2.43.0