From patchwork Mon May 7 13:57:26 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chris Wilson X-Patchwork-Id: 10384195 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 AEA7560318 for ; Mon, 7 May 2018 13:57:54 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8F78C1FFE4 for ; Mon, 7 May 2018 13:57:54 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 847162022C; Mon, 7 May 2018 13:57:54 +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 421231FFE4 for ; Mon, 7 May 2018 13:57:54 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id B2F1D89143; Mon, 7 May 2018 13:57:52 +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 59C6C89143 for ; Mon, 7 May 2018 13:57:50 +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 11622001-1500050 for multiple; Mon, 07 May 2018 14:57:34 +0100 Received: by haswell.alporthouse.com (sSMTP sendmail emulation); Mon, 07 May 2018 14:57:34 +0100 From: Chris Wilson To: intel-gfx@lists.freedesktop.org Date: Mon, 7 May 2018 14:57:26 +0100 Message-Id: <20180507135731.10587-2-chris@chris-wilson.co.uk> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180507135731.10587-1-chris@chris-wilson.co.uk> References: <20180507135731.10587-1-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 2/7] drm/i915: Disable tasklet scheduling across initial scheduling 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 During request submission, we call the engine->schedule() function so that we may reorder the active requests as required for inheriting the new request's priority. This may schedule several tasklets to run on the local CPU, but we will need to schedule the tasklets again for the new request. Delay all the local tasklets until the end, so that we only have to process the queue just once. v2: Beware PREEMPT_RCU, as then local_bh_disable() is then not a superset of rcu_read_lock(). Signed-off-by: Chris Wilson Cc: Tvrtko Ursulin Cc: Mika Kuoppala Reviewed-by: Tvrtko Ursulin --- drivers/gpu/drm/i915/i915_request.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c index e4cf76ec14a6..f336942229cf 100644 --- a/drivers/gpu/drm/i915/i915_request.c +++ b/drivers/gpu/drm/i915/i915_request.c @@ -1110,12 +1110,11 @@ void __i915_request_add(struct i915_request *request, bool flush_caches) * decide whether to preempt the entire chain so that it is ready to * run at the earliest possible convenience. */ - rcu_read_lock(); + local_bh_disable(); + rcu_read_lock(); /* RCU serialisation for set-wedged protection */ if (engine->schedule) engine->schedule(request, &request->ctx->sched); rcu_read_unlock(); - - local_bh_disable(); i915_sw_fence_commit(&request->submit); local_bh_enable(); /* Kick the execlists tasklet if just scheduled */