From patchwork Thu Oct 6 21:38:12 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Harrison X-Patchwork-Id: 13000756 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 7CA1AC433FE for ; Thu, 6 Oct 2022 21:38:07 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id A935B10E8D5; Thu, 6 Oct 2022 21:37:24 +0000 (UTC) Received: from mga17.intel.com (mga17.intel.com [192.55.52.151]) by gabe.freedesktop.org (Postfix) with ESMTPS id 1EBBC10E4FF; Thu, 6 Oct 2022 21:37:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1665092229; x=1696628229; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=16e4dab4lV5mo9Wxt1/9MaR9zOyTsfTE2RXghu4YBms=; b=mSx1Ry8A85va10JLtJ9d3595eG4QjsiNPkGifpvXr3n5CqW64Xs/KwRT 8SE7cfJmaZC1Sxbh0q+jwH1275pInY8RUQTJJmvA6ZJkqfxw0/RrzA0na O5wl/Ao15I7o5uDV1351jvkXiIh2DwkFJYHftsv+sSOj+eSVJthgT1jrg JrHEraA0pxwUFyREV0ouDqobs13OwlYuFvgLD7/BciuOPzPKn5+dxUutI AWNiRc38eeRx12I//ZBcTd8SfcXjz+s3C6EgN8hm8p315PH5r24Ho8UAI Z6zMyXRUkhcAnzrfcMvsBqvDQbD+cUlpioYpn/K8NpCR6tmn5azuNoJkz A==; X-IronPort-AV: E=McAfee;i="6500,9779,10492"; a="283945773" X-IronPort-AV: E=Sophos;i="5.95,164,1661842800"; d="scan'208";a="283945773" Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 06 Oct 2022 14:37:08 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10492"; a="627176772" X-IronPort-AV: E=Sophos;i="5.95,164,1661842800"; d="scan'208";a="627176772" Received: from relo-linux-5.jf.intel.com ([10.165.21.188]) by fmsmga007.fm.intel.com with ESMTP; 06 Oct 2022 14:37:08 -0700 From: John.C.Harrison@Intel.com To: Intel-GFX@Lists.FreeDesktop.Org Subject: [PATCH v5 3/4] drm/i915: Make the heartbeat play nice with long pre-emption timeouts Date: Thu, 6 Oct 2022 14:38:12 -0700 Message-Id: <20221006213813.1563435-4-John.C.Harrison@Intel.com> X-Mailer: git-send-email 2.37.3 In-Reply-To: <20221006213813.1563435-1-John.C.Harrison@Intel.com> References: <20221006213813.1563435-1-John.C.Harrison@Intel.com> MIME-Version: 1.0 Organization: Intel Corporation (UK) Ltd. - Co. Reg. #1134945 - Pipers Way, Swindon SN3 1RJ X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: John Harrison , DRI-Devel@Lists.FreeDesktop.Org Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" From: John Harrison Compute workloads are inherently not pre-emptible for long periods on current hardware. As a workaround for this, the pre-emption timeout for compute capable engines was disabled. This is undesirable with GuC submission as it prevents per engine reset of hung contexts. Hence the next patch will re-enable the timeout but bumped up by an order of magnitude. However, the heartbeat might not respect that. Depending upon current activity, a pre-emption to the heartbeat pulse might not even be attempted until the last heartbeat period. Which means that only one period is granted for the pre-emption to occur. With the aforesaid bump, the pre-emption timeout could be significantly larger than this heartbeat period. So adjust the heartbeat code to take the pre-emption timeout into account. When it reaches the final (high priority) period, it now ensures the delay before hitting reset is bigger than the pre-emption timeout. v2: Fix for selftests which adjust the heartbeat period manually. v3: Add FIXME comment about selftests. Add extra FIXME comment and drm_notices when setting heartbeat to a non-default value (review feedback from Tvrtko) Signed-off-by: John Harrison Reviewed-by: Tvrtko Ursulin --- .../gpu/drm/i915/gt/intel_engine_heartbeat.c | 39 +++++++++++++++++++ 1 file changed, 39 insertions(+) diff --git a/drivers/gpu/drm/i915/gt/intel_engine_heartbeat.c b/drivers/gpu/drm/i915/gt/intel_engine_heartbeat.c index a3698f611f457..9a527e1f5be65 100644 --- a/drivers/gpu/drm/i915/gt/intel_engine_heartbeat.c +++ b/drivers/gpu/drm/i915/gt/intel_engine_heartbeat.c @@ -22,9 +22,37 @@ static bool next_heartbeat(struct intel_engine_cs *engine) { + struct i915_request *rq; long delay; delay = READ_ONCE(engine->props.heartbeat_interval_ms); + + rq = engine->heartbeat.systole; + + /* + * FIXME: The final period extension is disabled if the period has been + * modified from the default. This is to prevent issues with certain + * selftests which override the value and expect specific behaviour. + * Once the selftests have been updated to either cope with variable + * heartbeat periods (or to override the pre-emption timeout as well, + * or just to add a selftest specific override of the extension), the + * generic override can be removed. + */ + if (rq && rq->sched.attr.priority >= I915_PRIORITY_BARRIER && + delay == engine->defaults.heartbeat_interval_ms) { + long longer; + + /* + * The final try is at the highest priority possible. Up until now + * a pre-emption might not even have been attempted. So make sure + * this last attempt allows enough time for a pre-emption to occur. + */ + longer = READ_ONCE(engine->props.preempt_timeout_ms) * 2; + longer = intel_clamp_heartbeat_interval_ms(engine, longer); + if (longer > delay) + delay = longer; + } + if (!delay) return false; @@ -288,6 +316,17 @@ int intel_engine_set_heartbeat(struct intel_engine_cs *engine, if (!delay && !intel_engine_has_preempt_reset(engine)) return -ENODEV; + /* FIXME: Remove together with equally marked hack in next_heartbeat. */ + if (delay != engine->defaults.heartbeat_interval_ms && + delay < 2 * engine->props.preempt_timeout_ms) { + if (intel_engine_uses_guc(engine)) + drm_notice(&engine->i915->drm, "%s heartbeat interval adjusted to a non-default value which may downgrade individual engine resets to full GPU resets!\n", + engine->name); + else + drm_notice(&engine->i915->drm, "%s heartbeat interval adjusted to a non-default value which may cause engine resets to target innocent contexts!\n", + engine->name); + } + intel_engine_pm_get(engine); err = mutex_lock_interruptible(&ce->timeline->mutex);