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=-14.3 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 CC2CFC433F5 for ; Mon, 20 Sep 2021 08:47:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A564B60EB4 for ; Mon, 20 Sep 2021 08:47:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235952AbhITIsx (ORCPT ); Mon, 20 Sep 2021 04:48:53 -0400 Received: from mga14.intel.com ([192.55.52.115]:20260 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231625AbhITIsw (ORCPT ); Mon, 20 Sep 2021 04:48:52 -0400 X-IronPort-AV: E=McAfee;i="6200,9189,10112"; a="222739230" X-IronPort-AV: E=Sophos;i="5.85,307,1624345200"; d="scan'208";a="222739230" Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Sep 2021 01:47:26 -0700 X-IronPort-AV: E=Sophos;i="5.85,307,1624345200"; d="scan'208";a="473500252" Received: from gbradyx-mobl2.ger.corp.intel.com (HELO [10.213.235.119]) ([10.213.235.119]) by fmsmga007-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Sep 2021 01:47:24 -0700 Subject: Re: [Intel-gfx] [PATCH 14/26] drm/i915: use the new iterator in i915_sw_fence_await_reservation v3 From: Tvrtko Ursulin To: =?UTF-8?Q?Christian_K=c3=b6nig?= , linaro-mm-sig@lists.linaro.org, dri-devel@lists.freedesktop.org, linux-media@vger.kernel.org, intel-gfx@lists.freedesktop.org Cc: daniel@ffwll.ch References: <20210917123513.1106-1-christian.koenig@amd.com> <20210917123513.1106-15-christian.koenig@amd.com> <93b93f00-7ad3-9ea3-e947-77297b4552c9@linux.intel.com> Organization: Intel Corporation UK Plc Message-ID: <60595ff8-7935-c0a4-7c0f-2a4c3a1d62b9@linux.intel.com> Date: Mon, 20 Sep 2021 09:47:23 +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: <93b93f00-7ad3-9ea3-e947-77297b4552c9@linux.intel.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org On 20/09/2021 09:45, Tvrtko Ursulin wrote: > > On 17/09/2021 13:35, Christian König wrote: >> Simplifying the code a bit. >> >> v2: use dma_resv_for_each_fence instead, according to Tvrtko the lock is >>      held here anyway. >> v3: back to using dma_resv_for_each_fence_unlocked. > > It did not work out - what happened? Wait, my suggestion to try the locked iterator was against i915_request_await_object. I haven't looked at this one at the time or even now. Regards, Tvrtko > Regards, > > Tvrtko > >> Signed-off-by: Christian König >> --- >>   drivers/gpu/drm/i915/i915_sw_fence.c | 57 ++++++++-------------------- >>   1 file changed, 15 insertions(+), 42 deletions(-) >> >> diff --git a/drivers/gpu/drm/i915/i915_sw_fence.c >> b/drivers/gpu/drm/i915/i915_sw_fence.c >> index c589a681da77..7635b0478ea5 100644 >> --- a/drivers/gpu/drm/i915/i915_sw_fence.c >> +++ b/drivers/gpu/drm/i915/i915_sw_fence.c >> @@ -572,56 +572,29 @@ int i915_sw_fence_await_reservation(struct >> i915_sw_fence *fence, >>                       unsigned long timeout, >>                       gfp_t gfp) >>   { >> -    struct dma_fence *excl; >> +    struct dma_resv_iter cursor; >> +    struct dma_fence *f; >>       int ret = 0, pending; >>       debug_fence_assert(fence); >>       might_sleep_if(gfpflags_allow_blocking(gfp)); >> -    if (write) { >> -        struct dma_fence **shared; >> -        unsigned int count, i; >> - >> -        ret = dma_resv_get_fences(resv, &excl, &count, &shared); >> -        if (ret) >> -            return ret; >> - >> -        for (i = 0; i < count; i++) { >> -            if (shared[i]->ops == exclude) >> -                continue; >> - >> -            pending = i915_sw_fence_await_dma_fence(fence, >> -                                shared[i], >> -                                timeout, >> -                                gfp); >> -            if (pending < 0) { >> -                ret = pending; >> -                break; >> -            } >> - >> -            ret |= pending; >> -        } >> - >> -        for (i = 0; i < count; i++) >> -            dma_fence_put(shared[i]); >> -        kfree(shared); >> -    } else { >> -        excl = dma_resv_get_excl_unlocked(resv); >> -    } >> - >> -    if (ret >= 0 && excl && excl->ops != exclude) { >> -        pending = i915_sw_fence_await_dma_fence(fence, >> -                            excl, >> -                            timeout, >> +    rcu_read_lock(); >> +    dma_resv_iter_begin(&cursor, resv, write); >> +    dma_resv_for_each_fence_unlocked(&cursor, f) { >> +        rcu_read_unlock(); >> +        pending = i915_sw_fence_await_dma_fence(fence, f, timeout, >>                               gfp); >> -        if (pending < 0) >> +        rcu_read_lock(); >> +        if (pending < 0) { >>               ret = pending; >> -        else >> -            ret |= pending; >> -    } >> - >> -    dma_fence_put(excl); >> +            break; >> +        } >> +        ret |= pending; >> +    } >> +    dma_resv_iter_end(&cursor); >> +    rcu_read_unlock(); >>       return ret; >>   } >>