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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (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 D5459C5DF87 for ; Fri, 21 Aug 2026 09:43:50 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 4EC5D10F286; Fri, 21 Aug 2026 09:43:50 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="DRj6AIrB"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.18]) by gabe.freedesktop.org (Postfix) with ESMTPS id 7546A10F286 for ; Fri, 21 Aug 2026 09:43:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1787305393; x=1818841393; h=message-id:subject:from:to:cc:date:in-reply-to: references:content-transfer-encoding:mime-version; bh=FgHxMk22Lx/+ZW+yYuGeNlCLi0bgPixNScZrVyYJSc4=; b=DRj6AIrBlWzpVUXfwtB1WtBUbtfaKzP8pvJ1aYoPkdlyTQDtxFVhCorz ZcMQKxihd+Un2sp2SDuYCoR3EHV/M7S41tt/lqm6bg7MZykBYLeOMZBos R0qQAT5m2lyWG4L0m3NOFpi/0g9yPS8I4+xbKTucK9zRcWnxN3e3HFZKQ UACg3GYZ9WIb1YGmwizf/D6XJth+ok27dYBUGUmuCI0qYjgl4is0w2ZFi bZt88EnfkwHqmoYwhtkFVVJrZ4UaMx44sq4dm3YVFpq+Ux6ZVYFwxwteW O5c8DfkO6wE6h2niY3eK/lJ5HlJ84jI5r6MoCyLnYK5QzxzlCwlkzfpXd w==; X-CSE-ConnectionGUID: KXaolSB3RECTZ4nds8krIA== X-CSE-MsgGUID: UO2bRBynT56j1+DdqrXS3w== X-IronPort-AV: E=McAfee;i="6800,10657,11881"; a="87911732" X-IronPort-AV: E=Sophos;i="6.25,234,1779174000"; d="scan'208";a="87911732" Received: from fmviesa010.fm.intel.com ([10.60.135.150]) by orvoesa110.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Aug 2026 02:43:13 -0700 X-CSE-ConnectionGUID: NRW/ZOONTwyPq1Yf6x7aGw== X-CSE-MsgGUID: MtxXHBPESPO8+9xDCu1cPA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.25,234,1779174000"; d="scan'208";a="262577942" Received: from jkrzyszt-mobl2.ger.corp.intel.com ([10.245.246.165]) by fmviesa010-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Aug 2026 02:43:11 -0700 Message-ID: <341d0d27d10daf87a9d2f4e191082b04dd69b9c1.camel@linux.intel.com> Subject: Re: [PATCH] tests/core_hotunplug: add *-with-load subtests exercising GPU workload during hotplug From: Janusz Krzysztofik To: Nitin Gote , igt-dev@lists.freedesktop.org Cc: Matthew Auld , Kamil Konieczny Date: Fri, 21 Aug 2026 11:43:09 +0200 In-Reply-To: <20260821065838.1865108-2-nitin.r.gote@intel.com> References: <20260821065838.1865108-2-nitin.r.gote@intel.com> Organization: Intel Technology Poland sp. z o.o. - ul. Slowackiego 173, 80-298 Gdansk - KRS 101882 - NIP 957-07-52-316 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.60.2 MIME-Version: 1.0 X-BeenThere: igt-dev@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Development mailing list for IGT GPU Tools List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: igt-dev-bounces@lists.freedesktop.org Sender: "igt-dev" Hi Nitin, Good job, however, I think we still need some improvements. On Fri, 2026-08-21 at 12:28 +0530, Nitin Gote wrote: > The six fd-holding hot* subtests keep a DRM fd open across unbind/unplug > but leave the GPU idle, so the kernel hotplug path is never exercised > against an active workload. >=20 > Add six new dedicated *-with-load subtests that run a GPU spinner across > the unbind/unplug sequence so the device is removed while a workload is > actively using it. >=20 > The workload helpers use an explicit chipset dispatch block in > workload_start()/stop() so that other vendors can contribute > support by adding an else-if branch. New subtests are gated on > workload_available(), which currently covers DRIVER_XE and DRIVER_INTEL, > and returns false (SKIP) on any other driver. >=20 > igt_spin_free() is avoided in workload_stop() since the device may be > gone by then -- igt_spin_end() writes the stop condition via a userspace > mmap and lets the DRM fd close reclaim kernel-side resources. >=20 > Validated on BMG and DG2 with a KASAN-enabled kernel: > all six new subtests pass with no KASAN reports. >=20 > v4: Rebase to latest igt. > Also the failure seen with the new core_hotunplug "with-load" > IGT subtests is fixed by kmd patch: > https://patchwork.freedesktop.org/series/171989/ >=20 > v3: Extend struct gpu_workload with a union of vendor-named members > to match the chipset dispatch in workload_start()/stop(). (Janusz) >=20 > v2: Pass the hotunplug priv struct to workload_start()/stop() > and dispatch via an explicit if/else-if chipset block to invite > other vendors to contribute. (Janusz) >=20 > Cc: Matthew Auld > Cc: Janusz Krzysztofik > Cc: Kamil Konieczny > Reviewed-by: Janusz Krzysztofik > Signed-off-by: Nitin Gote > --- > tests/core_hotunplug.c | 294 +++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 294 insertions(+) >=20 > diff --git a/tests/core_hotunplug.c b/tests/core_hotunplug.c > index 33de65369..b11a4231b 100644 > --- a/tests/core_hotunplug.c > +++ b/tests/core_hotunplug.c > @@ -80,6 +80,34 @@ > * SUBTEST: unplug-rescan > * Description: Check if a device believed to be closed can be cleanly > * unplugged, then restored > + * > + * SUBTEST: hotunbind-rebind-with-load > + * Description: Check if the driver can be cleanly unbound from an open = device > + * with a background GPU workload in flight, then released and > + * rebound > + * > + * SUBTEST: hotunplug-rescan-with-load > + * Description: Check if an open device with a background GPU workload i= n > + * flight can be cleanly unplugged, then released and restored > + * > + * SUBTEST: hotrebind-with-load > + * Description: Check if the driver can be cleanly rebound to a device w= ith a > + * still open hot unbound driver instance while a background GPU > + * workload is in flight > + * > + * SUBTEST: hotreplug-with-load > + * Description: Check if a hot unplugged and still open device can be cl= eanly > + * restored while a background GPU workload is in flight > + * > + * SUBTEST: hotrebind-lateclose-with-load > + * Description: Check if a hot unbound driver instance still open after = hot > + * rebind with a background GPU workload in flight can be cleanly > + * released > + * > + * SUBTEST: hotreplug-lateclose-with-load > + * Description: Check if an instance of a still open while hot replugged > + * device with a background GPU workload in flight can be cleanly > + * released > */ > =20 > IGT_TEST_DESCRIPTION("Examine behavior of a driver on device hot unplug"= ); > @@ -550,6 +578,56 @@ static void post_healthcheck(struct hotunplug *priv) > cleanup(priv); > } > =20 > +/* GPU workload helpers */ > + > +struct gpu_workload { > + union { > + struct { > + igt_spin_t *spin; > + uint64_t ahnd; > + } intel; /* Xe and i915 */ > + }; > +}; > + > +static bool workload_available(int chipset) > +{ > + return chipset =3D=3D DRIVER_XE || chipset =3D=3D DRIVER_INTEL; NIT: I think a switch (chipset) { case DRIVER_XE: ... } construct, here=C2= =A0 and=C2=A0consequently below in workload_start/stop, could be=C2=A0more effe= ctive and=C2=A0 more easily extendable=C2=A0with potential=C2=A0future additions from other= vendors,=C2=A0 but that can be refactored later, on a first such addition. > +} > + > +static void workload_start(struct hotunplug *priv, int fd, > + struct gpu_workload *w) > +{ > + if (priv->chipset =3D=3D DRIVER_XE || priv->chipset =3D=3D DRIVER_INTEL= ) { > + local_debug("%s\n", "starting GPU spinner"); > + priv->failure =3D "GPU workload start failure!"; > + w->intel.ahnd =3D intel_allocator_open(fd, 0, INTEL_ALLOCATOR_RELOC); > + w->intel.spin =3D igt_spin_new(fd, .ahnd =3D w->intel.ahnd); > + priv->failure =3D NULL; > + } > +} > + > +static void workload_stop(struct hotunplug *priv, struct gpu_workload *w= ) > +{ > + if (priv->chipset =3D=3D DRIVER_XE || priv->chipset =3D=3D DRIVER_INTEL= ) { > + if (!w->intel.spin) > + return; Since igt_fail() can be called from inside igt_spin_new(), workload_start() can fail leaving an open ahnd but no spin. We need to handle that case. > + > + /* > + * The device may be gone (unbind/unplug), so avoid > + * igt_spin_free(): on Xe it would wait forever on a syncobj > + * that never signals; on i915 it would touch the dead fd via > + * gem_munmap()/gem_close(). Instead, end the spinner via a > + * userspace mmap write and let the DRM fd close reclaim the > + * kernel-side resources. > + */ > + local_debug("%s\n", "stopping GPU spinner"); > + igt_spin_end(w->intel.spin); > + put_ahnd(w->intel.ahnd); > + w->intel.spin =3D NULL; > + w->intel.ahnd =3D 0; > + } > +} > + > /* Subtests */ > =20 > static void unbind_rebind(struct hotunplug *priv) > @@ -664,6 +742,150 @@ static void hotreplug_lateclose(struct hotunplug *p= riv) > igt_assert_f(healthcheck(priv, false), "%s\n", priv->failure); > } > =20 > +static void hotunbind_rebind_with_load(struct hotunplug *priv) > +{ > + struct gpu_workload w =3D { 0 }; > + > + pre_check(priv); > + > + igt_require_f(workload_available(priv->chipset), > + "No GPU workload support for this driver\n"); > + > + priv->fd.drm =3D local_drm_open_driver(false, "", " for hot unbind"); > + > + workload_start(priv, priv->fd.drm, &w); > + > + driver_unbind(priv, "hot ", 0); Since igt_fail() can be called from driver_unbind(), as well as from other= =C2=A0 functions called between workload_start() and workload_stop() in other=C2= =A0 subtests below, we need=C2=A0to address those cases to be on the safe side. We could e.g.: - embed struct gpu_workload inside struct hotunplug, - extend cleanup() (or recover()) function with another workload_stop(). Thanks, Janusz > + > + workload_stop(priv, &w); > + > + priv->fd.drm =3D close_device(priv->fd.drm, "late ", "unbound "); > + igt_assert_eq(priv->fd.drm, -1); > + > + driver_bind(priv, 0); > + > + igt_assert_f(healthcheck(priv, false), "%s\n", priv->failure); > +} > + > +static void hotunplug_rescan_with_load(struct hotunplug *priv) > +{ > + struct gpu_workload w =3D { 0 }; > + > + pre_check(priv); > + > + igt_require_f(workload_available(priv->chipset), > + "No GPU workload support for this driver\n"); > + > + priv->fd.drm =3D local_drm_open_driver(false, "", " for hot unplug"); > + > + workload_start(priv, priv->fd.drm, &w); > + > + device_unplug(priv, "hot ", 0); > + > + workload_stop(priv, &w); > + > + priv->fd.drm =3D close_device(priv->fd.drm, "late ", "removed "); > + igt_assert_eq(priv->fd.drm, -1); > + > + bus_rescan(priv, 0); > + > + igt_assert_f(healthcheck(priv, false), "%s\n", priv->failure); > +} > + > +static void hotrebind_with_load(struct hotunplug *priv) > +{ > + struct gpu_workload w =3D { 0 }; > + > + pre_check(priv); > + > + igt_require_f(workload_available(priv->chipset), > + "No GPU workload support for this driver\n"); > + > + priv->fd.drm =3D local_drm_open_driver(false, "", " for hot rebind"); > + > + workload_start(priv, priv->fd.drm, &w); > + > + driver_unbind(priv, "hot ", 60); > + > + driver_bind(priv, 0); > + > + workload_stop(priv, &w); > + > + igt_assert_f(healthcheck(priv, false), "%s\n", priv->failure); > +} > + > +static void hotreplug_with_load(struct hotunplug *priv) > +{ > + struct gpu_workload w =3D { 0 }; > + > + pre_check(priv); > + > + igt_require_f(workload_available(priv->chipset), > + "No GPU workload support for this driver\n"); > + > + priv->fd.drm =3D local_drm_open_driver(false, "", " for hot replug"); > + > + workload_start(priv, priv->fd.drm, &w); > + > + device_unplug(priv, "hot ", 60); > + > + bus_rescan(priv, 0); > + > + workload_stop(priv, &w); > + > + igt_assert_f(healthcheck(priv, false), "%s\n", priv->failure); > +} > + > +static void hotrebind_lateclose_with_load(struct hotunplug *priv) > +{ > + struct gpu_workload w =3D { 0 }; > + > + pre_check(priv); > + > + igt_require_f(workload_available(priv->chipset), > + "No GPU workload support for this driver\n"); > + > + priv->fd.drm =3D local_drm_open_driver(false, "", " for hot rebind"); > + > + workload_start(priv, priv->fd.drm, &w); > + > + driver_unbind(priv, "hot ", 60); > + > + driver_bind(priv, 0); > + > + workload_stop(priv, &w); > + > + priv->fd.drm =3D close_device(priv->fd.drm, "late ", "unbound "); > + igt_assert_eq(priv->fd.drm, -1); > + > + igt_assert_f(healthcheck(priv, false), "%s\n", priv->failure); > +} > + > +static void hotreplug_lateclose_with_load(struct hotunplug *priv) > +{ > + struct gpu_workload w =3D { 0 }; > + > + pre_check(priv); > + > + igt_require_f(workload_available(priv->chipset), > + "No GPU workload support for this driver\n"); > + > + priv->fd.drm =3D local_drm_open_driver(false, "", " for hot replug"); > + > + workload_start(priv, priv->fd.drm, &w); > + > + device_unplug(priv, "hot ", 60); > + > + bus_rescan(priv, 0); > + > + workload_stop(priv, &w); > + > + priv->fd.drm =3D close_device(priv->fd.drm, "late ", "removed "); > + igt_assert_eq(priv->fd.drm, -1); > + > + igt_assert_f(healthcheck(priv, false), "%s\n", priv->failure); > +} > + > /* Main */ > =20 > int igt_main() > @@ -802,6 +1024,78 @@ int igt_main() > recover(&priv); > } > =20 > + igt_fixture() > + post_healthcheck(&priv); > + > + igt_subtest_group() { > + igt_describe("Check if the driver can be cleanly unbound from an open = device with a background GPU workload in flight, then released and rebound"= ); > + igt_subtest("hotunbind-rebind-with-load") > + hotunbind_rebind_with_load(&priv); > + > + igt_fixture() > + recover(&priv); > + } > + > + igt_fixture() > + post_healthcheck(&priv); > + > + igt_subtest_group() { > + igt_describe("Check if an open device with a background GPU workload i= n flight can be cleanly unplugged, then released and restored"); > + igt_subtest("hotunplug-rescan-with-load") > + hotunplug_rescan_with_load(&priv); > + > + igt_fixture() > + recover(&priv); > + } > + > + igt_fixture() > + post_healthcheck(&priv); > + > + igt_subtest_group() { > + igt_describe("Check if the driver can be cleanly rebound to a device w= ith a still open hot unbound driver instance while a background GPU workloa= d is in flight"); > + igt_subtest("hotrebind-with-load") > + hotrebind_with_load(&priv); > + > + igt_fixture() > + recover(&priv); > + } > + > + igt_fixture() > + post_healthcheck(&priv); > + > + igt_subtest_group() { > + igt_describe("Check if a hot unplugged and still open device can be cl= eanly restored while a background GPU workload is in flight"); > + igt_subtest("hotreplug-with-load") > + hotreplug_with_load(&priv); > + > + igt_fixture() > + recover(&priv); > + } > + > + igt_fixture() > + post_healthcheck(&priv); > + > + igt_subtest_group() { > + igt_describe("Check if a hot unbound driver instance still open after = hot rebind with a background GPU workload in flight can be cleanly released= "); > + igt_subtest("hotrebind-lateclose-with-load") > + hotrebind_lateclose_with_load(&priv); > + > + igt_fixture() > + recover(&priv); > + } > + > + igt_fixture() > + post_healthcheck(&priv); > + > + igt_subtest_group() { > + igt_describe("Check if an instance of a still open while hot replugged= device with a background GPU workload in flight can be cleanly released"); > + igt_subtest("hotreplug-lateclose-with-load") > + hotreplug_lateclose_with_load(&priv); > + > + igt_fixture() > + recover(&priv); > + } > + > igt_fixture() { > post_healthcheck(&priv); > =20