From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from 009.lax.mailroute.net (009.lax.mailroute.net [199.89.1.12]) (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 BD16517C215; Fri, 22 Nov 2024 22:18:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=199.89.1.12 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732313899; cv=none; b=ie89xSYvUCErToQ4xYNw8UdZYhOezDKSLGZp3qi+LvnWkCShZG1jZMNcdMdUb3y9Y+cHhvjScEtz6OC13S530O08Ky9/gwKC1a2UnyUh+8R6YdsyA4Bi2vSQLl901BEYPUCSjTcF5D7ljLupWLCR4J4glzyg3v4Xrf88IN51te4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732313899; c=relaxed/simple; bh=lMjgrtTcMD4b1SW1Y2OSEccQ5BSxGRFtVQDLVVuTrX0=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=qQfCzT8lL0oM+6zhttKOUonnk1JrHKYtsMu8t5NxN2bmh2eyLvXNWlNlxs8vYWJjyaKC5L6HQ36c75pqct6B8fB9HWU8Obank+Oh8XCohyaGnWEOOvGbznSHsIToMwVvltFrBu9gqDYVoC7CEPdtCU6PbRw9isCuoa51kTnYmaY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=acm.org; spf=pass smtp.mailfrom=acm.org; dkim=pass (2048-bit key) header.d=acm.org header.i=@acm.org header.b=LdlxPW1r; arc=none smtp.client-ip=199.89.1.12 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=acm.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=acm.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=acm.org header.i=@acm.org header.b="LdlxPW1r" Received: from localhost (localhost [127.0.0.1]) by 009.lax.mailroute.net (Postfix) with ESMTP id 4Xw8cn05gDzlgMVW; Fri, 22 Nov 2024 22:18:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=acm.org; h= content-transfer-encoding:content-type:content-type:in-reply-to :from:from:content-language:references:subject:subject :user-agent:mime-version:date:date:message-id:received:received; s=mr01; t=1732313893; x=1734905894; bh=Z45+r6YX3qsDn7MweFwZioaj MgJoNThdbLqP8orzRrI=; b=LdlxPW1rrsJVdlIwiZoZ5sJUVwUiDUwrgOZTzj6f YS1iOwl5Vp3zhs0yYaG46/dUQLbeXVhRsaPtQjpumbYMTER6miHZA5PqIBWaUlTX TYig0odET7DZjvZm4UkPFrNz/3AAW/TKXCiL5UIBtdUACa6zLHS5Ln8+yZP6TB6G t4g2SIv60kOI2P2/v/mp5DojHpDDLCcY8K8UNf/CRiSIGJ5ILIrD0S3Bi1HelBHh dNsc8tyBebqp+z/9y5/6kICcyztkJOsFZP5AcKbILq52yAUF5r95hyYPOoLFc3+L /9+CnC7OkOF2jxyadFpa4OgEErrev3xpUY3SGP6Eo55ebg== X-Virus-Scanned: by MailRoute Received: from 009.lax.mailroute.net ([127.0.0.1]) by localhost (009.lax [127.0.0.1]) (mroute_mailscanner, port 10029) with LMTP id SbD8TEb3FKhY; Fri, 22 Nov 2024 22:18:13 +0000 (UTC) Received: from [100.66.154.22] (unknown [104.135.204.82]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: bvanassche@acm.org) by 009.lax.mailroute.net (Postfix) with ESMTPSA id 4Xw8ch4qN6zlgMVV; Fri, 22 Nov 2024 22:18:12 +0000 (UTC) Message-ID: Date: Fri, 22 Nov 2024 14:18:10 -0800 Precedence: bulk X-Mailing-List: linux-scsi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 2/2] block: remove the ioprio field from struct request To: Sam Protsenko , Christoph Hellwig Cc: axboe@kernel.dk, linux-block@vger.kernel.org, linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org References: <20241112170050.1612998-3-hch@lst.de> <20241122050419.21973-1-semen.protsenko@linaro.org> <20241122120444.GA25679@lst.de> Content-Language: en-US From: Bart Van Assche In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: quoted-printable On 11/22/24 1:55 PM, Sam Protsenko wrote: > On Fri, Nov 22, 2024 at 6:04=E2=80=AFAM Christoph Hellwig = wrote: >> >> On Thu, Nov 21, 2024 at 11:04:19PM -0600, Sam Protsenko wrote: >>> Hi Christoph, >>> >>> This patch causes a regression on E850-96 board. Specifically, there = are >>> two noticeable time lags when booting Debian rootfs: >> >> What storage driver does this board use? Anything else interesting >> about the setup? >> >=20 > It's an Exynos based board with eMMC, so it uses DW MMC driver, with > Exynos glue layer on top of it, so: >=20 > drivers/mmc/host/dw_mmc.c > drivers/mmc/host/dw_mmc-exynos.c >=20 > I'm using the regular ARM64 defconfig. Nothing fancy about this setup > neither, the device tree with eMMC definition (mmc_0) is here: >=20 > arch/arm64/boot/dts/exynos/exynos850-e850-96.dts >=20 > FWIW, I was able to narrow down the issue to dd_insert_request() > function. With this hack the freeze is gone: >=20 > 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 =3D hctx->queue; > struct deadline_data *dd =3D q->elevator->elevator_data; > const enum dd_data_dir data_dir =3D rq_data_dir(rq); > - u16 ioprio =3D req_get_ioprio(rq); > + u16 ioprio =3D 0; /* the same as old req->ioprio */ > u8 ioprio_class =3D IOPRIO_PRIO_CLASS(ioprio); > struct dd_per_prio *per_prio; > enum dd_prio prio; > 8<-------------------------------------------------------------------->= 8 >=20 > Does it tell you anything about where the possible issue can be? It seems like eMMC devices do not tolerate I/O prioritization. How about disabling I/O prioritization for eMMC setups? Is the ioprio cgroup controller perhaps activated by the user space software that is running on this setup? Thanks, Bart.