From patchwork Thu Sep 5 09:26:45 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christian Loehle X-Patchwork-Id: 13792019 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 4CB98198A25; Thu, 5 Sep 2024 09:27:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725528475; cv=none; b=Gtay8WlFsG9Vln3Lxtl6nVbKuG1iG+aU8RBhQ+GanP59lSRSBBtCybEd/jBB8912qo5FXZTzzLVNyy/7caJDcv7+iPBFeocvwfyTQmFV+T5L8x3dwblw+5cigthq3u+nN7dVjQKKza/wsezLdc84sJBbL+eFdYwPYSzHo5iZ2K4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725528475; c=relaxed/simple; bh=HhGLvHqBHzexJqM6r5ytVEg4CW0oOFnrqqKCCerjEA0=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=YVnj5tappVRgdX/uxzD4Yl+CoZ/LSlViEFI24otws47gMLZnC343pKeD0pB5lD/Lqxzr5HyOTxnapDAvyr5wu2ZptNL/ylr0g/S49vfd99eM8EmXd4o5Yh9vw9IDpJ40n37NnrdlWHQ5BO1aNC1i0R39Y5lxn+vEw4ZnS5eLMpc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 410701063; Thu, 5 Sep 2024 02:28:20 -0700 (PDT) Received: from e127648.arm.com (unknown [10.57.75.86]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 6DA053F73F; Thu, 5 Sep 2024 02:27:49 -0700 (PDT) From: Christian Loehle To: linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, rafael@kernel.org, peterz@infradead.org Cc: juri.lelli@redhat.com, mingo@redhat.com, dietmar.eggemann@arm.com, vschneid@redhat.com, vincent.guittot@linaro.org, Johannes.Thumshirn@wdc.com, adrian.hunter@intel.com, ulf.hansson@linaro.org, bvanassche@acm.org, andres@anarazel.de, asml.silence@gmail.com, linux-block@vger.kernel.org, io-uring@vger.kernel.org, qyousef@layalina.io, dsmythies@telus.net, axboe@kernel.dk, Christian Loehle Subject: [RFC PATCH 8/8] io_uring: Do not set iowait before sleeping Date: Thu, 5 Sep 2024 10:26:45 +0100 Message-Id: <20240905092645.2885200-9-christian.loehle@arm.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240905092645.2885200-1-christian.loehle@arm.com> References: <20240905092645.2885200-1-christian.loehle@arm.com> Precedence: bulk X-Mailing-List: io-uring@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Setting in_iowait was introduced in commit 8a796565cec3 ("io_uring: Use io_schedule* in cqring wait") to tackle a perf regression that was caused by menu taking iowait into account for synchronous IO and thus not selecting deeper states like in the io_uring counterpart. That behaviour is gone, so the workaround can be removed. Signed-off-by: Christian Loehle --- io_uring/io_uring.c | 17 ----------------- 1 file changed, 17 deletions(-) diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index 3942db160f18..c819d40bdcf0 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -2341,15 +2341,6 @@ int io_run_task_work_sig(struct io_ring_ctx *ctx) return 0; } -static bool current_pending_io(void) -{ - struct io_uring_task *tctx = current->io_uring; - - if (!tctx) - return false; - return percpu_counter_read_positive(&tctx->inflight); -} - /* when returns >0, the caller should retry */ static inline int io_cqring_wait_schedule(struct io_ring_ctx *ctx, struct io_wait_queue *iowq) @@ -2367,19 +2358,11 @@ static inline int io_cqring_wait_schedule(struct io_ring_ctx *ctx, if (unlikely(io_should_wake(iowq))) return 0; - /* - * Mark us as being in io_wait if we have pending requests, so cpufreq - * can take into account that the task is waiting for IO - turns out - * to be important for low QD IO. - */ - if (current_pending_io()) - current->in_iowait = 1; ret = 0; if (iowq->timeout == KTIME_MAX) schedule(); else if (!schedule_hrtimeout(&iowq->timeout, HRTIMER_MODE_ABS)) ret = -ETIME; - current->in_iowait = 0; return ret; }