From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) (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 54BEC2119; Mon, 25 Nov 2024 07:37:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=213.95.11.211 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732520223; cv=none; b=LqCKn0PCn0tdy/Pw9ouuLEjcwXmX+t+bZc0CQ0ujSZ1M6VsjZ9DLZY5A29wj7/+rB525hafL/1Nr6vPo43HBviBwFBkEagBNITG3K/jfmSEWkEcgQxZfBdw1+Bbit5Z5EmuUqnGARI9pCOSLLHdIILtDfgOkk4EdjPE+vNVfLMI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732520223; c=relaxed/simple; bh=ykyCCKl8gtxzVQHKbbY6Y3XWba4Xq2lT14Me0ZDDDvg=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=ORtjvUlpj17uaKOCBob12m1sPIQthj4BhyWKKOTMBQSj21D3lqNUQu6oCis6cTi0UxUavfGlbPAUH7zgK7dkSya+n6RH6PkXEg+EZmJz+3whE9+uRDYJAdSvx6ZwYt+zuyOB4exTVafq3ARfYUTytm5HJFBH9NRo5Ck+anb+uis= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de; spf=pass smtp.mailfrom=lst.de; arc=none smtp.client-ip=213.95.11.211 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=lst.de Received: by verein.lst.de (Postfix, from userid 2407) id 703A768D09; Mon, 25 Nov 2024 08:36:58 +0100 (CET) Date: Mon, 25 Nov 2024 08:36:58 +0100 From: Christoph Hellwig To: Sam Protsenko Cc: Christoph Hellwig , axboe@kernel.dk, linux-block@vger.kernel.org, linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/2] block: remove the ioprio field from struct request Message-ID: <20241125073658.GA15834@lst.de> References: <20241112170050.1612998-3-hch@lst.de> <20241122050419.21973-1-semen.protsenko@linaro.org> <20241122120444.GA25679@lst.de> 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: User-Agent: Mutt/1.5.17 (2007-11-01) On Fri, Nov 22, 2024 at 03:55:23PM -0600, Sam Protsenko wrote: > It's an Exynos based board with eMMC, so it uses DW MMC driver, with > Exynos glue layer on top of it, so: > > drivers/mmc/host/dw_mmc.c > drivers/mmc/host/dw_mmc-exynos.c > > I'm using the regular ARM64 defconfig. Nothing fancy about this setup > neither, the device tree with eMMC definition (mmc_0) is here: > > arch/arm64/boot/dts/exynos/exynos850-e850-96.dts Thanks. eMMC itself never looks at the ioprio field. > FWIW, I was able to narrow down the issue to dd_insert_request() > function. With this hack the freeze is gone: Sounds like it isn't the driver that matters here, but the scheduler. > > 8<-------------------------------------------------------------------->8 > diff --git a/block/mq-deadline.c b/block/mq-deadline.c > index acdc28756d9d..83d272b66e71 100644 > --- a/block/mq-deadline.c > +++ b/block/mq-deadline.c > @@ -676,7 +676,7 @@ static void dd_insert_request(struct blk_mq_hw_ctx > *hctx, struct request *rq, > struct request_queue *q = hctx->queue; > struct deadline_data *dd = q->elevator->elevator_data; > const enum dd_data_dir data_dir = rq_data_dir(rq); > - u16 ioprio = req_get_ioprio(rq); > + u16 ioprio = 0; /* the same as old req->ioprio */ > u8 ioprio_class = IOPRIO_PRIO_CLASS(ioprio); > struct dd_per_prio *per_prio; > enum dd_prio prio; > 8<-------------------------------------------------------------------->8 > > Does it tell you anything about where the possible issue can be? Can you dump the ioprities you see here with and without the reverted patch?