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=-16.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,HK_RANDOM_FROM,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 016BBC433F5 for ; Tue, 14 Sep 2021 13:18:20 +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 AFF9E610A6 for ; Tue, 14 Sep 2021 13:18:19 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org AFF9E610A6 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=lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 88E1F89E7C; Tue, 14 Sep 2021 13:18:18 +0000 (UTC) Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) by gabe.freedesktop.org (Postfix) with ESMTPS id 0CEFE89E7C; Tue, 14 Sep 2021 13:18:17 +0000 (UTC) X-IronPort-AV: E=McAfee;i="6200,9189,10106"; a="307540613" X-IronPort-AV: E=Sophos;i="5.85,292,1624345200"; d="scan'208";a="307540613" Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Sep 2021 06:18:16 -0700 X-IronPort-AV: E=Sophos;i="5.85,292,1624345200"; d="scan'208";a="544067834" Received: from ocascan-mobl.ger.corp.intel.com (HELO [10.213.234.116]) ([10.213.234.116]) by fmsmga003-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Sep 2021 06:18:14 -0700 Subject: Re: [Intel-gfx] [PATCH 13/26] drm/i915: use the new iterator in i915_gem_busy_ioctl To: =?UTF-8?Q?Christian_K=c3=b6nig?= , linaro-mm-sig@lists.linaro.org, dri-devel@lists.freedesktop.org, linux-media@vger.kernel.org Cc: daniel@ffwll.ch, intel-gfx@lists.freedesktop.org References: <20210913131707.45639-1-christian.koenig@amd.com> <20210913131707.45639-14-christian.koenig@amd.com> From: Tvrtko Ursulin Organization: Intel Corporation UK Plc Message-ID: <7d5d6454-2d74-53e7-73ea-2d0d60b3c44c@linux.intel.com> Date: Tue, 14 Sep 2021 14:18:12 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: <20210913131707.45639-14-christian.koenig@amd.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit 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: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On 13/09/2021 14:16, Christian König wrote: > This makes the function much simpler since the complex > retry logic is now handled else where. > > Signed-off-by: Christian König > --- > drivers/gpu/drm/i915/gem/i915_gem_busy.c | 30 +++++++----------------- > 1 file changed, 9 insertions(+), 21 deletions(-) > > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_busy.c b/drivers/gpu/drm/i915/gem/i915_gem_busy.c > index 6234e17259c1..c6c6d747b33e 100644 > --- a/drivers/gpu/drm/i915/gem/i915_gem_busy.c > +++ b/drivers/gpu/drm/i915/gem/i915_gem_busy.c > @@ -82,8 +82,8 @@ i915_gem_busy_ioctl(struct drm_device *dev, void *data, > { > struct drm_i915_gem_busy *args = data; > struct drm_i915_gem_object *obj; > - struct dma_resv_list *list; > - unsigned int seq; > + struct dma_resv_cursor cursor; > + struct dma_fence *fence; > int err; > > err = -ENOENT; > @@ -109,28 +109,16 @@ i915_gem_busy_ioctl(struct drm_device *dev, void *data, > * to report the overall busyness. This is what the wait-ioctl does. > * > */ > -retry: > - seq = raw_read_seqcount(&obj->base.resv->seq); > - > - /* Translate the exclusive fence to the READ *and* WRITE engine */ > - args->busy = busy_check_writer(dma_resv_excl_fence(obj->base.resv)); > - > - /* Translate shared fences to READ set of engines */ > - list = dma_resv_shared_list(obj->base.resv); > - if (list) { > - unsigned int shared_count = list->shared_count, i; > - > - for (i = 0; i < shared_count; ++i) { > - struct dma_fence *fence = > - rcu_dereference(list->shared[i]); > - > + args->busy = false; > + dma_resv_for_each_fence_unlocked(obj->base.resv, &cursor, true, fence) { To preserve strictly identical behaviour, I think add before the below if-else: if (cursor.is_first) args->busy = 0; As mentioned elsewhere in the thread I am not convinced it is hugely important, all that can happen without it is that stale read activity gets reported, and this ioctl is not really that sensitive to that. Regards, Tvrtko > + if (cursor.is_exclusive) > + /* Translate the exclusive fence to the READ *and* WRITE engine */ > + args->busy = busy_check_writer(fence); > + else > + /* Translate shared fences to READ set of engines */ > args->busy |= busy_check_reader(fence); > - } > } > > - if (args->busy && read_seqcount_retry(&obj->base.resv->seq, seq)) > - goto retry; > - > err = 0; > out: > rcu_read_unlock(); >