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, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable 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 0C195C48BD1 for ; Thu, 10 Jun 2021 10:04:07 +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 994F761184 for ; Thu, 10 Jun 2021 10:04:06 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 994F761184 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=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 755516ECBC; Thu, 10 Jun 2021 10:04:05 +0000 (UTC) Received: from mga17.intel.com (mga17.intel.com [192.55.52.151]) by gabe.freedesktop.org (Postfix) with ESMTPS id 5D1BD6ECAC; Thu, 10 Jun 2021 10:04:03 +0000 (UTC) IronPort-SDR: keu534A0UZcd2/7gwJvIs6D3F1+U7LCyciKRHaEj1GnTFMS8i5mdriwxoRSCvnNenx/Qa7U/R4 4KFTLaHZmrUg== X-IronPort-AV: E=McAfee;i="6200,9189,10010"; a="185642419" X-IronPort-AV: E=Sophos;i="5.83,263,1616482800"; d="scan'208";a="185642419" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Jun 2021 03:03:58 -0700 IronPort-SDR: CkIu7NghF7rMMe3AVGKdmSXDUQOaadEak4FGC+LhJ2F+D2XPnMP3f2i+e0XcsoRy6CqW45cRkB 0JuYwo9VIK3A== X-IronPort-AV: E=Sophos;i="5.83,263,1616482800"; d="scan'208";a="448662293" Received: from rabolton-mobl.ger.corp.intel.com (HELO [10.213.197.140]) ([10.213.197.140]) by orsmga008-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Jun 2021 03:03:55 -0700 Subject: Re: [Intel-gfx] [PATCH 1/5] drm/i915: Move intel_engine_free_request_pool to i915_request.c To: Jason Ekstrand , dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org References: <20210609212959.471209-1-jason@jlekstrand.net> <20210609212959.471209-2-jason@jlekstrand.net> From: Tvrtko Ursulin Organization: Intel Corporation UK Plc Message-ID: <0f63cba3-ec2f-c246-1375-5b1bced593f5@linux.intel.com> Date: Thu, 10 Jun 2021 11:03:53 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.1 MIME-Version: 1.0 In-Reply-To: <20210609212959.471209-2-jason@jlekstrand.net> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit 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: , Cc: Daniel Vetter , Matthew Auld Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On 09/06/2021 22:29, Jason Ekstrand wrote: > This appears to break encapsulation by moving an intel_engine_cs > function to a i915_request file. However, this function is > intrinsically tied to the lifetime rules and allocation scheme of > i915_request and having it in intel_engine_cs.c leaks details of > i915_request. We have an abstraction leak either way. Since > i915_request's allocation scheme is far more subtle than the simple > pointer that is intel_engine_cs.request_pool, it's probably better to > keep i915_request's details to itself. > > Signed-off-by: Jason Ekstrand > Cc: Jon Bloomfield > Cc: Daniel Vetter > Cc: Matthew Auld > Cc: Maarten Lankhorst > --- > drivers/gpu/drm/i915/gt/intel_engine_cs.c | 8 -------- > drivers/gpu/drm/i915/i915_request.c | 7 +++++-- > drivers/gpu/drm/i915/i915_request.h | 2 -- > 3 files changed, 5 insertions(+), 12 deletions(-) > > diff --git a/drivers/gpu/drm/i915/gt/intel_engine_cs.c b/drivers/gpu/drm/i915/gt/intel_engine_cs.c > index 9ceddfbb1687d..df6b80ec84199 100644 > --- a/drivers/gpu/drm/i915/gt/intel_engine_cs.c > +++ b/drivers/gpu/drm/i915/gt/intel_engine_cs.c > @@ -422,14 +422,6 @@ void intel_engines_release(struct intel_gt *gt) > } > } > > -void intel_engine_free_request_pool(struct intel_engine_cs *engine) > -{ > - if (!engine->request_pool) > - return; > - > - kmem_cache_free(i915_request_slab_cache(), engine->request_pool); Argument that the slab cache shouldn't be exported from i915_request.c sounds good to me. But I think step better than simply reversing the break of encapsulation (And it's even worse because it leaks much higher level object!) could be to export a freeing helper from i915_request.c, engine pool would then use: void __i915_request_free(...) { kmem_cache_free(...); } ? Regards, Tvrtko > -} > - > void intel_engines_free(struct intel_gt *gt) > { > struct intel_engine_cs *engine; > diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c > index 1014c71cf7f52..48c5f8527854b 100644 > --- a/drivers/gpu/drm/i915/i915_request.c > +++ b/drivers/gpu/drm/i915/i915_request.c > @@ -106,9 +106,12 @@ static signed long i915_fence_wait(struct dma_fence *fence, > timeout); > } > > -struct kmem_cache *i915_request_slab_cache(void) > +void intel_engine_free_request_pool(struct intel_engine_cs *engine) > { > - return global.slab_requests; > + if (!engine->request_pool) > + return; > + > + kmem_cache_free(global.slab_requests, engine->request_pool); > } > > static void i915_fence_release(struct dma_fence *fence) > diff --git a/drivers/gpu/drm/i915/i915_request.h b/drivers/gpu/drm/i915/i915_request.h > index 270f6cd37650c..f84c38d29f988 100644 > --- a/drivers/gpu/drm/i915/i915_request.h > +++ b/drivers/gpu/drm/i915/i915_request.h > @@ -300,8 +300,6 @@ static inline bool dma_fence_is_i915(const struct dma_fence *fence) > return fence->ops == &i915_fence_ops; > } > > -struct kmem_cache *i915_request_slab_cache(void); > - > struct i915_request * __must_check > __i915_request_create(struct intel_context *ce, gfp_t gfp); > struct i915_request * __must_check >