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 X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 82889C10F27 for ; Tue, 10 Mar 2020 15:11:26 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 6576420873 for ; Tue, 10 Mar 2020 15:11:26 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6576420873 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=intel-gfx-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 13BF089CD4; Tue, 10 Mar 2020 15:11:26 +0000 (UTC) Received: from mga04.intel.com (mga04.intel.com [192.55.52.120]) by gabe.freedesktop.org (Postfix) with ESMTPS id A08E389CD4 for ; Tue, 10 Mar 2020 15:11:24 +0000 (UTC) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by fmsmga104.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 10 Mar 2020 08:11:24 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,537,1574150400"; d="scan'208";a="234376386" Received: from gaia.fi.intel.com ([10.237.72.192]) by fmsmga007.fm.intel.com with ESMTP; 10 Mar 2020 08:11:23 -0700 Received: by gaia.fi.intel.com (Postfix, from userid 1000) id A70BB5C1DD2; Tue, 10 Mar 2020 17:01:15 +0200 (EET) From: Mika Kuoppala To: Chris Wilson , intel-gfx@lists.freedesktop.org In-Reply-To: <20200310141320.24149-1-chris@chris-wilson.co.uk> References: <20200310141320.24149-1-chris@chris-wilson.co.uk> Date: Tue, 10 Mar 2020 17:01:15 +0200 Message-ID: <87tv2w1cg4.fsf@gaia.fi.intel.com> MIME-Version: 1.0 Subject: Re: [Intel-gfx] [PATCH 1/3] drm/i915/gt: Mark up racy reads for intel_context.inflight X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" Chris Wilson writes: > When being used across multiple real engines inside a virtual engine, > the intel_context.inflight is updated atomically, and so we must > annotate the racy read from outside the owning context. > > [11142.482846] BUG: KCSAN: data-race in __execlists_submission_tasklet [i915] / __execlists_submission_tasklet [i915] > [11142.482867] > [11142.482878] write (marked) to 0xffff8881f257b5e0 of 8 bytes by interrupt on cpu 2: > [11142.483107] __execlists_submission_tasklet+0x1d33/0x2120 [i915] > [11142.483336] execlists_submission_tasklet+0xd3/0x170 [i915] > [11142.483355] tasklet_action_common.isra.0+0x42/0xa0 > [11142.483371] __do_softirq+0xd7/0x2cd > [11142.483384] irq_exit+0xbe/0xe0 > [11142.483401] do_IRQ+0x51/0x100 > [11142.483424] ret_from_intr+0x0/0x1c > [11142.483446] do_idle+0x133/0x1f0 > [11142.483465] cpu_startup_entry+0x14/0x16 > [11142.483483] start_secondary+0x120/0x180 > [11142.483498] secondary_startup_64+0xa4/0xb0 > [11142.483512] > [11142.483528] read to 0xffff8881f257b5e0 of 8 bytes by interrupt on cpu 1: > [11142.483755] __execlists_submission_tasklet+0x14e/0x2120 [i915] > [11142.483981] execlists_submission_tasklet+0xd3/0x170 [i915] > [11142.483999] tasklet_action_common.isra.0+0x42/0xa0 > [11142.484014] __do_softirq+0xd7/0x2cd > [11142.484028] do_softirq_own_stack+0x2a/0x40 > [11142.484046] do_softirq.part.0+0x26/0x30 > [11142.484071] __local_bh_enable_ip+0x46/0x50 > [11142.484299] i915_gem_do_execbuffer+0x39c1/0x4e50 [i915] > [11142.484528] i915_gem_execbuffer2_ioctl+0x2c3/0x580 [i915] > [11142.484546] drm_ioctl_kernel+0xe4/0x120 > [11142.484559] drm_ioctl+0x297/0x4c7 > [11142.484572] ksys_ioctl+0x89/0xb0 > [11142.484586] __x64_sys_ioctl+0x42/0x60 > [11142.484610] do_syscall_64+0x6e/0x2c0 > [11142.484627] entry_SYSCALL_64_after_hwframe+0x44/0xa9 > > Signed-off-by: Chris Wilson Reviewed-by: Mika Kuoppala > --- > drivers/gpu/drm/i915/gt/intel_context_types.h | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/i915/gt/intel_context_types.h b/drivers/gpu/drm/i915/gt/intel_context_types.h > index 11278343b9b5..0f3b68b95c56 100644 > --- a/drivers/gpu/drm/i915/gt/intel_context_types.h > +++ b/drivers/gpu/drm/i915/gt/intel_context_types.h > @@ -45,8 +45,8 @@ struct intel_context { > > struct intel_engine_cs *engine; > struct intel_engine_cs *inflight; > -#define intel_context_inflight(ce) ptr_mask_bits((ce)->inflight, 2) > -#define intel_context_inflight_count(ce) ptr_unmask_bits((ce)->inflight, 2) > +#define intel_context_inflight(ce) ptr_mask_bits(READ_ONCE((ce)->inflight), 2) > +#define intel_context_inflight_count(ce) ptr_unmask_bits(READ_ONCE((ce)->inflight), 2) > > struct i915_address_space *vm; > struct i915_gem_context __rcu *gem_context; > -- > 2.20.1 > > _______________________________________________ > Intel-gfx mailing list > Intel-gfx@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/intel-gfx _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx