From patchwork Sun Aug 2 16:44:12 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chris Wilson X-Patchwork-Id: 11696755 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id DF4121392 for ; Sun, 2 Aug 2020 16:44:27 +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 C775720738 for ; Sun, 2 Aug 2020 16:44:27 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C775720738 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=chris-wilson.co.uk 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 7A6056E17F; Sun, 2 Aug 2020 16:44:25 +0000 (UTC) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from fireflyinternet.com (unknown [77.68.26.236]) by gabe.freedesktop.org (Postfix) with ESMTPS id 2B60E6E17A for ; Sun, 2 Aug 2020 16:44:24 +0000 (UTC) X-Default-Received-SPF: pass (skip=forwardok (res=PASS)) x-ip-name=78.156.65.138; Received: from build.alporthouse.com (unverified [78.156.65.138]) by fireflyinternet.com (Firefly Internet (M1)) with ESMTP id 22010461-1500050 for multiple; Sun, 02 Aug 2020 17:44:21 +0100 From: Chris Wilson To: intel-gfx@lists.freedesktop.org Date: Sun, 2 Aug 2020 17:44:12 +0100 Message-Id: <20200802164412.2738-43-chris@chris-wilson.co.uk> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200802164412.2738-1-chris@chris-wilson.co.uk> References: <20200802164412.2738-1-chris@chris-wilson.co.uk> MIME-Version: 1.0 Subject: [Intel-gfx] [PATCH 42/42] drm/i915/gt: Another tweak for flushing the tasklets 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: , Cc: Chris Wilson Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" tasklet_kill() ensures that we _yield_ the processor until a remote tasklet is completed. However, this leads to a starvation condition as being at the bottom of the scheduler's runqueue means that anything else is able to run, including all hogs keeping the tasklet occupied. Signed-off-by: Chris Wilson --- drivers/gpu/drm/i915/gt/intel_engine_cs.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/i915/gt/intel_engine_cs.c b/drivers/gpu/drm/i915/gt/intel_engine_cs.c index e3bda3509cd0..5c08c29e58af 100644 --- a/drivers/gpu/drm/i915/gt/intel_engine_cs.c +++ b/drivers/gpu/drm/i915/gt/intel_engine_cs.c @@ -1197,10 +1197,6 @@ void intel_engine_flush_submission(struct intel_engine_cs *engine) if (!t->func) return; - /* Synchronise and wait for the tasklet on another CPU */ - tasklet_kill(t); - - /* Having cancelled the tasklet, ensure that is run */ local_bh_disable(); if (tasklet_trylock(t)) { /* Must wait for any GPU reset in progress. */ @@ -1209,6 +1205,9 @@ void intel_engine_flush_submission(struct intel_engine_cs *engine) tasklet_unlock(t); } local_bh_enable(); + + /* Synchronise and wait for the tasklet on another CPU */ + tasklet_unlock_wait(t); } /**