From patchwork Tue Jun 9 16:05:52 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chris Wilson X-Patchwork-Id: 224713 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=-9.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT 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 ACA76C433E1 for ; Tue, 9 Jun 2020 16:13:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9296620774 for ; Tue, 9 Jun 2020 16:13:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731193AbgFIQNl (ORCPT ); Tue, 9 Jun 2020 12:13:41 -0400 Received: from mga02.intel.com ([134.134.136.20]:23416 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731126AbgFIQNW (ORCPT ); Tue, 9 Jun 2020 12:13:22 -0400 IronPort-SDR: mTzo8lA7H7gqXlGW2mzo0X9LHxI0oJJjx1SAfdKns+kW6u14+CyvMJLp1mUSDR/4Ko0IcXWHjL dmDhQ9PUbWXw== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga008.jf.intel.com ([10.7.209.65]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Jun 2020 09:13:21 -0700 IronPort-SDR: 3MT0a82VbHxYdpDdxwVZasiV9/OWeX7YjDFbud65t+6zGg+CtDIRaao1vEKzbgj9bbG8QaL5zk 1xJC0p8It2uw== X-IronPort-AV: E=Sophos;i="5.73,492,1583222400"; d="scan'208";a="306307387" Received: from gem-build.fi.intel.com (HELO localhost) ([10.237.72.180]) by orsmga008-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Jun 2020 09:13:20 -0700 From: Chris Wilson To: gfx-internal-devel@eclists.intel.com Cc: Chris Wilson , Tvrtko Ursulin , stable@vger.kernel.org Subject: [PATCH 087/185] drm/i915: Defer semaphore priority bumping to a workqueue Date: Tue, 9 Jun 2020 16:05:52 +0000 Message-Id: <20200609160731.287073-88-chris@chris-wilson.co.uk> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200609160731.287073-1-chris@chris-wilson.co.uk> References: <20200609160731.287073-1-chris@chris-wilson.co.uk> MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org Since the semaphore fence may be signaled from inside an interrupt handler from inside a request holding its request->lock, we cannot then enter into the engine->active.lock for processing the semaphore priority bump as we may traverse our call tree and end up on another held request. CPU 0: [ 2243.218864] _raw_spin_lock_irqsave+0x9a/0xb0 [ 2243.218867] i915_schedule_bump_priority+0x49/0x80 [i915] [ 2243.218869] semaphore_notify+0x6d/0x98 [i915] [ 2243.218871] __i915_sw_fence_complete+0x61/0x420 [i915] [ 2243.218874] ? kmem_cache_free+0x211/0x290 [ 2243.218876] i915_sw_fence_complete+0x58/0x80 [i915] [ 2243.218879] dma_i915_sw_fence_wake+0x3e/0x80 [i915] [ 2243.218881] signal_irq_work+0x571/0x690 [i915] [ 2243.218883] irq_work_run_list+0xd7/0x120 [ 2243.218885] irq_work_run+0x1d/0x50 [ 2243.218887] smp_irq_work_interrupt+0x21/0x30 [ 2243.218889] irq_work_interrupt+0xf/0x20 CPU 1: [ 2242.173107] _raw_spin_lock+0x8f/0xa0 [ 2242.173110] __i915_request_submit+0x64/0x4a0 [i915] [ 2242.173112] __execlists_submission_tasklet+0x8ee/0x2120 [i915] [ 2242.173114] ? i915_sched_lookup_priolist+0x1e3/0x2b0 [i915] [ 2242.173117] execlists_submit_request+0x2e8/0x2f0 [i915] [ 2242.173119] submit_notify+0x8f/0xc0 [i915] [ 2242.173121] __i915_sw_fence_complete+0x61/0x420 [i915] [ 2242.173124] ? _raw_spin_unlock_irqrestore+0x39/0x40 [ 2242.173137] i915_sw_fence_complete+0x58/0x80 [i915] [ 2242.173140] i915_sw_fence_commit+0x16/0x20 [i915] Closes: https://gitlab.freedesktop.org/drm/intel/issues/1318 Fixes: b7404c7ecb38 ("drm/i915: Bump ready tasks ahead of busywaits") Signed-off-by: Chris Wilson Cc: Tvrtko Ursulin Cc: # v5.2+ Reviewed-by: Tvrtko Ursulin Link: https://patchwork.freedesktop.org/patch/msgid/20200310101720.9944-1-chris@chris-wilson.co.uk (cherry picked from commit 209df10bb4536c81c2540df96c02cd079435357f) --- drivers/gpu/drm/i915/i915_request.c | 22 +++++++++++++++++----- drivers/gpu/drm/i915/i915_request.h | 2 ++ 2 files changed, 19 insertions(+), 5 deletions(-) --------------------------------------------------------------------- Intel Corporation (UK) Limited Registered No. 1134945 (England) Registered Office: Pipers Way, Swindon SN3 1RJ VAT No: 860 2173 47 This e-mail and any attachments may contain confidential material for the sole use of the intended recipient(s). Any review or distribution by others is strictly prohibited. If you are not the intended recipient, please contact the sender and delete all copies. diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c index e7f96ce0b071e..c7573e66107d0 100644 --- a/drivers/gpu/drm/i915/i915_request.c +++ b/drivers/gpu/drm/i915/i915_request.c @@ -629,19 +629,31 @@ submit_notify(struct i915_sw_fence *fence, enum i915_sw_fence_notify state) return NOTIFY_DONE; } +static void irq_semaphore_cb(struct irq_work *wrk) +{ + struct i915_request *rq = + container_of(wrk, typeof(*rq), semaphore_work); + + i915_schedule_bump_priority(rq, I915_PRIORITY_NOSEMAPHORE); + i915_request_put(rq); +} + static int __i915_sw_fence_call semaphore_notify(struct i915_sw_fence *fence, enum i915_sw_fence_notify state) { - struct i915_request *request = - container_of(fence, typeof(*request), semaphore); + struct i915_request *rq = container_of(fence, typeof(*rq), semaphore); switch (state) { case FENCE_COMPLETE: - i915_schedule_bump_priority(request, I915_PRIORITY_NOSEMAPHORE); + if (!(READ_ONCE(rq->sched.attr.priority) & I915_PRIORITY_NOSEMAPHORE)) { + i915_request_get(rq); + init_irq_work(&rq->semaphore_work, irq_semaphore_cb); + irq_work_queue(&rq->semaphore_work); + } break; case FENCE_FREE: - i915_request_put(request); + i915_request_put(rq); break; } @@ -1503,9 +1515,9 @@ void __i915_request_queue(struct i915_request *rq, * decide whether to preempt the entire chain so that it is ready to * run at the earliest possible convenience. */ - i915_sw_fence_commit(&rq->semaphore); if (attr && rq->engine->schedule) rq->engine->schedule(rq, attr); + i915_sw_fence_commit(&rq->semaphore); i915_sw_fence_commit(&rq->submit); } diff --git a/drivers/gpu/drm/i915/i915_request.h b/drivers/gpu/drm/i915/i915_request.h index 32ddba894243f..64501b4b3e3a2 100644 --- a/drivers/gpu/drm/i915/i915_request.h +++ b/drivers/gpu/drm/i915/i915_request.h @@ -26,6 +26,7 @@ #define I915_REQUEST_H #include +#include #include #include "gem/i915_gem_context_types.h" @@ -208,6 +209,7 @@ struct i915_request { }; struct list_head execute_cb; struct i915_sw_fence semaphore; + struct irq_work semaphore_work; /* * A list of everyone we wait upon, and everyone who waits upon us.