From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists1p.gnu.org (lists1p.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 81AD2C61DD3 for ; Thu, 3 Sep 2026 15:09:08 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists1p.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1x293i-00040a-CD; Thu, 03 Sep 2026 11:08:58 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists1p.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1x293c-0003sg-LH for qemu-devel@nongnu.org; Thu, 03 Sep 2026 11:08:53 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1x293a-0005yE-Lq for qemu-devel@nongnu.org; Thu, 03 Sep 2026 11:08:52 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1788448129; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=KDJ99I4p8h4jmU+b08lmPHs5F4IlfAgMzBEcxDOx4Mw=; b=M75gA5fl9LOZr9xk6YHiG1v5Wr5vsnjZ+vMIY8NSSRbGbKdHVU9Wg+shVbl3KN+C1IR2ri dXzDqczp1IkgnPDM9ZWp6ria58NueQejRTQojfr3UAPbf4out3kr0xMjnvZGi0VVHAjuCH /WU3jjNq+SNCWEIbt1WdQRm7TPeiEhk= Received: from mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-651-d1LBqYjKPq6St-EuevwXkQ-1; Thu, 03 Sep 2026 11:08:45 -0400 X-MC-Unique: d1LBqYjKPq6St-EuevwXkQ-1 X-Mimecast-MFC-AGG-ID: d1LBqYjKPq6St-EuevwXkQ_1788448124 Received: from mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.12]) (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) by mx-prod-mc-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 33FB3195FDCA; Thu, 3 Sep 2026 15:08:44 +0000 (UTC) Received: from localhost (headnet05.pony-001.prod.iad2.dc.redhat.com [10.2.32.117]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 9FFAC1955F08; Thu, 3 Sep 2026 15:08:43 +0000 (UTC) Date: Thu, 3 Sep 2026 11:08:42 -0400 From: Stefan Hajnoczi To: Hanna Czenczek Cc: qemu-block@nongnu.org, qemu-devel@nongnu.org, Kevin Wolf , John Snow , "Denis V . Lunev" , Eric Blake , Markus Armbruster Subject: Re: [PATCH 8/9] block/accounting: Move latency_ns override down Message-ID: <20260903150842.GF825275@fedora> References: <20260831135206.126184-1-hreitz@redhat.com> <20260831135206.126184-9-hreitz@redhat.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="Qbc8asqZL6BCVZcw" Content-Disposition: inline In-Reply-To: <20260831135206.126184-9-hreitz@redhat.com> X-Scanned-By: MIMEDefang 3.0 on 10.30.177.12 Received-SPF: pass client-ip=170.10.129.124; envelope-from=stefanha@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: 12 X-Spam_score: 1.2 X-Spam_bar: + X-Spam_report: (1.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=0.001, RCVD_IN_SBL_CSS=3.335, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: qemu development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org --Qbc8asqZL6BCVZcw Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Aug 31, 2026 at 03:52:04PM +0200, Hanna Czenczek wrote: > I am not quite sure why `latency_ns` is overridden by a fixed value in > qtest mode because personally, I find it much better if I can > individually change requests' latency by modifying the qtest clock. It looks like tests/qemu-iotests/136 relies on a hardcoded constant so it can check min/max/avg against known values. >=20 > But I'm not going to change existing behavior for the histogram and > such, so I will just move this override after the latency has been > evaluated regarding a potential BLOCK_IO_DELAY event. That's fine if you aren't taking the same testing approach as tests/qemu-iotests/136. I think the benefit of hardcoding the value for testing is that it would become possible to trigger the latency threshold without worrying about timing in the test environment. >=20 > Signed-off-by: Hanna Czenczek > --- > block/accounting.c | 8 ++++---- > 1 file changed, 4 insertions(+), 4 deletions(-) >=20 > diff --git a/block/accounting.c b/block/accounting.c > index debf1924455..223becd2e04 100644 > --- a/block/accounting.c > +++ b/block/accounting.c > @@ -271,10 +271,6 @@ static void block_account_one_io(BlockAcctStats *sta= ts, BlockAcctCookie *cookie, > int64_t time_ns =3D qemu_clock_get_ns(clock_type); > int64_t latency_ns =3D time_ns - cookie->start_time_ns; > =20 > - if (qtest_enabled()) { > - latency_ns =3D qtest_latency_ns; > - } > - > assert(cookie->type < BLOCK_MAX_IOTYPE); > =20 > if (cookie->type =3D=3D BLOCK_ACCT_NONE) { > @@ -292,6 +288,10 @@ static void block_account_one_io(BlockAcctStats *sta= ts, BlockAcctCookie *cookie, > cookie->bytes); > } > =20 > + if (qtest_enabled()) { > + latency_ns =3D qtest_latency_ns; > + } > + > WITH_QEMU_LOCK_GUARD(&stats->lock) { > if (failed) { > stats->failed_ops[cookie->type]++; > --=20 > 2.55.0 >=20 --Qbc8asqZL6BCVZcw Content-Type: application/pgp-signature; name=signature.asc -----BEGIN PGP SIGNATURE----- iQEzBAEBCgAdFiEEhpWov9P5fNqsNXdanKSrs4Grc8gFAmqZjXoACgkQnKSrs4Gr c8hSVAf/WYQ2MXBZyE5HjRaIg7FDHsoa7bSoHMazoufxJe7FFu83RskDuws8Y3hA vEcoJ24N5hNomTA21i+uSMA6bL54UYZuwyP0IAV3H31AFwC+pYjlDY9Fd9CxqR9n dI+fB5n122pKtObxcg+c6Dd35oWqCQlBQx5qK8uFNJsO98syFgAkIZrKnz7D+qSR +V3iqOdMKrenGgQo/k3bn0gdM22uNjvli8fytdFcJQG8RVZkrIF1m5Eloagy4vI0 RoFhZQ8eN8Pf+OHRrQjY9p6bA+KzxdIXBTB5vRvNjRxt4zXveQRoZ4fnt/swQ7Wa 2Wt4oxzi4VisRvx1dDbT4+y2ZwPAVA== =00jh -----END PGP SIGNATURE----- --Qbc8asqZL6BCVZcw--