From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C93C8C433DB for ; Wed, 30 Dec 2020 14:24:42 +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 7B656221FA for ; Wed, 30 Dec 2020 14:24:42 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7B656221FA Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com 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 C574F89173; Wed, 30 Dec 2020 14:24:41 +0000 (UTC) Received: from mga12.intel.com (mga12.intel.com [192.55.52.136]) by gabe.freedesktop.org (Postfix) with ESMTPS id D1CE689173 for ; Wed, 30 Dec 2020 14:24:39 +0000 (UTC) IronPort-SDR: juOKtWxFMNy8Mip3jzCcWWLePgDixPSeHeeKd2Nm4UAVMvas7B4fDT/VSj1Se/h9HpUYBTGVXz /T+zFwJAOsyg== X-IronPort-AV: E=McAfee;i="6000,8403,9849"; a="155807390" X-IronPort-AV: E=Sophos;i="5.78,461,1599548400"; d="scan'208";a="155807390" Received: from orsmga002.jf.intel.com ([10.7.209.21]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Dec 2020 06:24:39 -0800 IronPort-SDR: ohHSl2F3MisjwMCkkf8OhGZn0hw8bCOWVJZh5nblD8GWae/SzxHCpif5VWwDGAS2UHu+tjAVoI AgyZTYGbAyOg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.78,461,1599548400"; d="scan'208";a="359237170" Received: from gaia.fi.intel.com ([10.237.72.192]) by orsmga002.jf.intel.com with ESMTP; 30 Dec 2020 06:24:38 -0800 Received: by gaia.fi.intel.com (Postfix, from userid 1000) id 1C70F5C20E0; Wed, 30 Dec 2020 16:22:07 +0200 (EET) From: Mika Kuoppala To: Chris Wilson , intel-gfx@lists.freedesktop.org In-Reply-To: <20201228155229.9516-6-chris@chris-wilson.co.uk> References: <20201228155229.9516-1-chris@chris-wilson.co.uk> <20201228155229.9516-6-chris@chris-wilson.co.uk> Date: Wed, 30 Dec 2020 16:22:07 +0200 Message-ID: <87v9cjl6gg.fsf@gaia.fi.intel.com> MIME-Version: 1.0 Subject: Re: [Intel-gfx] [PATCH 06/54] drm/i915: Drop i915_request.lock requirement for intel_rps_boost() 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 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" Chris Wilson writes: > Since we use a flag within i915_request.flags to indicate when we have > boosted the request (so that we only apply the boost) once, this can be > used as the serialisation with i915_request_retire() to avoid having to > explicitly take the i915_request.lock which is more heavily contended. > > Signed-off-by: Chris Wilson > --- > drivers/gpu/drm/i915/gt/intel_rps.c | 15 ++++++--------- > drivers/gpu/drm/i915/i915_request.c | 4 +--- > 2 files changed, 7 insertions(+), 12 deletions(-) > > diff --git a/drivers/gpu/drm/i915/gt/intel_rps.c b/drivers/gpu/drm/i915/gt/intel_rps.c > index f74d5e09e176..e1397b8d3586 100644 > --- a/drivers/gpu/drm/i915/gt/intel_rps.c > +++ b/drivers/gpu/drm/i915/gt/intel_rps.c > @@ -917,17 +917,15 @@ void intel_rps_park(struct intel_rps *rps) > > void intel_rps_boost(struct i915_request *rq) > { > - struct intel_rps *rps = &READ_ONCE(rq->engine)->gt->rps; > - unsigned long flags; > - > - if (i915_request_signaled(rq) || !intel_rps_is_active(rps)) > + if (i915_request_signaled(rq) || i915_request_has_waitboost(rq)) > return; > > /* Serializes with i915_request_retire() */ > - spin_lock_irqsave(&rq->lock, flags); > - if (!i915_request_has_waitboost(rq) && > - !dma_fence_is_signaled_locked(&rq->fence)) { > - set_bit(I915_FENCE_FLAG_BOOST, &rq->fence.flags); > + if (!test_and_set_bit(I915_FENCE_FLAG_BOOST, &rq->fence.flags)) { > + struct intel_rps *rps = &READ_ONCE(rq->engine)->gt->rps; > + > + if (!intel_rps_is_active(rps)) > + return; > > GT_TRACE(rps_to_gt(rps), "boost fence:%llx:%llx\n", > rq->fence.context, rq->fence.seqno); > @@ -938,7 +936,6 @@ void intel_rps_boost(struct i915_request *rq) > > atomic_inc(&rps->boosts); Looks of it, this does not need to be atomic. But topic for another patch. > } > - spin_unlock_irqrestore(&rq->lock, flags); > } > > int intel_rps_set(struct intel_rps *rps, u8 val) > diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c > index 2d2882344e40..2a7bad88038b 100644 > --- a/drivers/gpu/drm/i915/i915_request.c > +++ b/drivers/gpu/drm/i915/i915_request.c > @@ -307,10 +307,8 @@ bool i915_request_retire(struct i915_request *rq) > spin_unlock_irq(&rq->lock); > } > > - if (i915_request_has_waitboost(rq)) { > - GEM_BUG_ON(!atomic_read(&rq->engine->gt->rps.num_waiters)); > + if (test_and_set_bit(I915_FENCE_FLAG_BOOST, &rq->fence.flags)) > atomic_dec(&rq->engine->gt->rps.num_waiters); This should keep the num_waiters in sync. Reviewed-by: Mika Kuoppala > - } > > /* > * We only loosely track inflight requests across preemption, > -- > 2.20.1 > > _______________________________________________ > Intel-gfx mailing list > Intel-gfx@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/intel-gfx _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx