From patchwork Wed Jan 10 21:02:16 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Harrison X-Patchwork-Id: 13516560 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 C4F3AC4707B for ; Wed, 10 Jan 2024 21:04:34 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id A7B9010E68D; Wed, 10 Jan 2024 21:04:31 +0000 (UTC) Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.7]) by gabe.freedesktop.org (Postfix) with ESMTPS id 66E6210E699; Wed, 10 Jan 2024 21:04:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1704920670; x=1736456670; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=IKh2uVnW2bz0CgCKI3oi9r+Ie5VGsP8rbG0Vdbj+YmE=; b=X05xw0FmR7yp5ifSnbFGBzhE9UQAOFk4k7g6bVMOZ1U3v8G9NyJ8VIwK A/phvbH5Luudy4drfJrkB4g8nC9pmGrsTN9DcpRq2NGZ/sj8s/Wp76Nho 1HQtGL+hED2moUaQqbhvOANB3CcGYQt5a3qCUdTPyHRilgEu6IVcC+cMY nZoAvYClut4rKXznCkI3LBx9kmnmphx7wGtnJNFNASjnL6+Q9cvvKPp9j wP9gdLyIMUfXoF0531cvBh/xUSvPrgQsdehWZKxTagdkorH+E0y8Hjx4X OXGxYsrpFRmjfpmcSQol7yWHnWOOxaNJaP+mfkHCk4IgvvWyC8AO8KsiF w==; X-IronPort-AV: E=McAfee;i="6600,9927,10949"; a="20135195" X-IronPort-AV: E=Sophos;i="6.04,184,1695711600"; d="scan'208";a="20135195" Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmvoesa101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Jan 2024 13:00:14 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10949"; a="731959295" X-IronPort-AV: E=Sophos;i="6.04,184,1695711600"; d="scan'208";a="731959295" Received: from relo-linux-5.jf.intel.com ([10.165.21.152]) by orsmga003.jf.intel.com with ESMTP; 10 Jan 2024 13:00:14 -0800 From: John.C.Harrison@Intel.com To: Intel-GFX@Lists.FreeDesktop.Org Subject: [PATCH] drm/i915/gt: Restart the heartbeat timer when forcing a pulse Date: Wed, 10 Jan 2024 13:02:16 -0800 Message-ID: <20240110210216.4125092-1-John.C.Harrison@Intel.com> X-Mailer: git-send-email 2.43.0 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 The context persistence code does things like send super high priority heartbeat pulses to ensure any leaked context can still be pre-empted and thus isn't a total denial of service but only a minor denial of service. Unfortunately, it wasn't bothering to restart the heatbeat worker with a fresh timeout. Thus, if a persistent context happened to be closed just before the heartbeat was going to go ping anyway then the forced pulse would get a negligble execution time. And as the forced pulse is super high priority, the worker thread's next step is a reset. Which means a potentially innocent system randomly goes boom when attempting to close a context. So, force a re-schedule of the worker thread with the appropriate timeout. Signed-off-by: John Harrison Reviewed-by: Andi Shyti --- drivers/gpu/drm/i915/gt/intel_engine_heartbeat.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/gpu/drm/i915/gt/intel_engine_heartbeat.c b/drivers/gpu/drm/i915/gt/intel_engine_heartbeat.c index 1a8e2b7db0138..4ae2fa0b61dd4 100644 --- a/drivers/gpu/drm/i915/gt/intel_engine_heartbeat.c +++ b/drivers/gpu/drm/i915/gt/intel_engine_heartbeat.c @@ -290,6 +290,9 @@ static int __intel_engine_pulse(struct intel_engine_cs *engine) heartbeat_commit(rq, &attr); GEM_BUG_ON(rq->sched.attr.priority < I915_PRIORITY_BARRIER); + /* Ensure the forced pulse gets a full period to execute */ + next_heartbeat(engine); + return 0; }