From patchwork Sun May 6 17:13:28 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chris Wilson X-Patchwork-Id: 10382903 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 97EDE60353 for ; Sun, 6 May 2018 17:13:54 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7DD4128A40 for ; Sun, 6 May 2018 17:13:54 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 723AB28A48; Sun, 6 May 2018 17:13:54 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00, MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id C0B7328A40 for ; Sun, 6 May 2018 17:13:53 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id B25816E04D; Sun, 6 May 2018 17:13:51 +0000 (UTC) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from fireflyinternet.com (mail.fireflyinternet.com [109.228.58.192]) by gabe.freedesktop.org (Postfix) with ESMTPS id EDEC16E04D for ; Sun, 6 May 2018 17:13:49 +0000 (UTC) X-Default-Received-SPF: pass (skip=forwardok (res=PASS)) x-ip-name=78.156.65.138; Received: from haswell.alporthouse.com (unverified [78.156.65.138]) by fireflyinternet.com (Firefly Internet (M1)) with ESMTP id 11615324-1500050 for multiple; Sun, 06 May 2018 18:13:29 +0100 Received: by haswell.alporthouse.com (sSMTP sendmail emulation); Sun, 06 May 2018 18:13:29 +0100 From: Chris Wilson To: intel-gfx@lists.freedesktop.org Date: Sun, 6 May 2018 18:13:28 +0100 Message-Id: <20180506171328.30034-1-chris@chris-wilson.co.uk> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180506151557.10370-1-chris@chris-wilson.co.uk> References: <20180506151557.10370-1-chris@chris-wilson.co.uk> X-Originating-IP: 78.156.65.138 X-Country: code=GB country="United Kingdom" ip=78.156.65.138 Subject: [Intel-gfx] [PATCH v2] drm/i915: Speed up idle detection by kicking the tasklets X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" X-Virus-Scanned: ClamAV using ClamSMTP We rely on ksoftirqd to run in a timely fashion in order to drain the execlists queue. Quite frequently, it does not. In some cases we may see latencies of over 200ms triggering our idle timeouts and forcing us to declare the driver wedged! Thus we can speed up idle detection by bypassing ksoftirqd in these cases and flush our tasklet to confirm if we are indeed still waiting for the ELSP to drain. v2: Put the execlists.first check back; it is required for handling reset! References: https://bugs.freedesktop.org/show_bug.cgi?id=106373 Signed-off-by: Chris Wilson Cc: Tvrtko Ursulin Cc: Mika Kuoppala Reviewed-by: Mika Kuoppala --- drivers/gpu/drm/i915/intel_engine_cs.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_engine_cs.c b/drivers/gpu/drm/i915/intel_engine_cs.c index 70325e0824e3..a3111511ea1d 100644 --- a/drivers/gpu/drm/i915/intel_engine_cs.c +++ b/drivers/gpu/drm/i915/intel_engine_cs.c @@ -945,10 +945,19 @@ bool intel_engine_is_idle(struct intel_engine_cs *engine) return true; /* Waiting to drain ELSP? */ - if (READ_ONCE(engine->execlists.active)) - return false; + if (READ_ONCE(engine->execlists.active)) { + struct intel_engine_execlists *execlists = &engine->execlists; + + if (tasklet_trylock(&execlists->tasklet)) { + execlists->tasklet.func(execlists->tasklet.data); + tasklet_unlock(&execlists->tasklet); + } + + if (READ_ONCE(execlists->active)) + return false; + } - /* ELSP is empty, but there are ready requests? */ + /* ELSP is empty, but there are ready requests? E.g. after reset */ if (READ_ONCE(engine->execlists.first)) return false;