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=-7.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, HK_RANDOM_FROM,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 CBC44C4332B for ; Mon, 23 Mar 2020 10:38:11 +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 A798620769 for ; Mon, 23 Mar 2020 10:38:11 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A798620769 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 2707389DBF; Mon, 23 Mar 2020 10:38:11 +0000 (UTC) Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by gabe.freedesktop.org (Postfix) with ESMTPS id DCE0D89DBF for ; Mon, 23 Mar 2020 10:38:09 +0000 (UTC) IronPort-SDR: V70gRFqdpvdRxs8zBOIZqMvvza+VGkogEjxkpeZPooy5lC3I1DEYqCkQg8BcX2obAAwK2L+YcQ dEVoxlEXg5+g== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Mar 2020 03:38:09 -0700 IronPort-SDR: ZDy3Jm/YQ3axq6dISvhGn9QoQKHEYYWDGHcdKeg0NMlLDFywtDgKrM5eSTsn+qg75+/s0Bbe7h gxvs2br8fkvA== X-IronPort-AV: E=Sophos;i="5.72,296,1580803200"; d="scan'208";a="419459060" Received: from unknown (HELO [10.252.47.179]) ([10.252.47.179]) by orsmga005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Mar 2020 03:38:08 -0700 To: Chris Wilson , intel-gfx@lists.freedesktop.org References: <20200323092841.22240-1-chris@chris-wilson.co.uk> <20200323092841.22240-8-chris@chris-wilson.co.uk> From: Tvrtko Ursulin Organization: Intel Corporation UK Plc Message-ID: <9c23a5be-7baf-2196-e4ef-446caf9d709b@linux.intel.com> Date: Mon, 23 Mar 2020 10:38:06 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.4.1 MIME-Version: 1.0 In-Reply-To: <20200323092841.22240-8-chris@chris-wilson.co.uk> Content-Language: en-US Subject: Re: [Intel-gfx] [PATCH 8/8] drm/i915/gem: Avoid gem_context->mutex for simple vma lookup 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: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" On 23/03/2020 09:28, Chris Wilson wrote: > As we store the handle lookup inside a radix tree, we do not need the > gem_context->mutex except until we need to insert our lookup into the > common radix tree. This takes a small bit of rearranging to ensure that > the lut we insert into the tree is ready prior to actually inserting it > (as soon as it is exposed via the radixtree, it is visible to any other > submission). > > v2: For brownie points, remove the goto spaghetti. > v3: Tighten up the closed-handle checks. > > Signed-off-by: Chris Wilson > --- > .../gpu/drm/i915/gem/i915_gem_execbuffer.c | 136 +++++++++++------- > 1 file changed, 87 insertions(+), 49 deletions(-) > > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c > index e80c6f613feb..c643eec4dca0 100644 > --- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c > +++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c > @@ -481,7 +481,7 @@ eb_add_vma(struct i915_execbuffer *eb, > > GEM_BUG_ON(i915_vma_is_closed(vma)); > > - ev->vma = i915_vma_get(vma); > + ev->vma = vma; > ev->exec = entry; > ev->flags = entry->flags; > > @@ -728,77 +728,117 @@ static int eb_select_context(struct i915_execbuffer *eb) > return 0; > } > > -static int eb_lookup_vmas(struct i915_execbuffer *eb) > +static int __eb_add_lut(struct i915_execbuffer *eb, > + u32 handle, struct i915_vma *vma) > { > - struct radix_tree_root *handles_vma = &eb->gem_context->handles_vma; > - struct drm_i915_gem_object *obj; > - unsigned int i, batch; > + struct i915_gem_context *ctx = eb->gem_context; > + struct i915_lut_handle *lut; > int err; > > - if (unlikely(i915_gem_context_is_closed(eb->gem_context))) > - return -ENOENT; > + lut = i915_lut_handle_alloc(); > + if (unlikely(!lut)) > + return -ENOMEM; > > - INIT_LIST_HEAD(&eb->relocs); > - INIT_LIST_HEAD(&eb->unbound); > + i915_vma_get(vma); > + if (!atomic_fetch_inc(&vma->open_count)) > + i915_vma_reopen(vma); > + lut->handle = handle; > + lut->ctx = ctx; > + > + /* Check that the context hasn't been closed in the meantime */ > + err = -EINTR; > + if (!mutex_lock_interruptible(&ctx->mutex)) { > + err = -ENOENT; > + if (likely(!i915_gem_context_is_closed(ctx))) > + err = radix_tree_insert(&ctx->handles_vma, handle, vma); > + if (err == 0) { /* And nor has this handle */ > + struct drm_i915_gem_object *obj = vma->obj; > + > + i915_gem_object_lock(obj); > + if (idr_find(&eb->file->object_idr, handle) == obj) { > + list_add(&lut->obj_link, &obj->lut_list); > + } else { > + radix_tree_delete(&ctx->handles_vma, handle); > + err = -ENOENT; > + } > + i915_gem_object_unlock(obj); > + } > + mutex_unlock(&ctx->mutex); > + } > + if (unlikely(err)) > + goto err; > > - batch = eb_batch_index(eb); > + return 0; > > - for (i = 0; i < eb->buffer_count; i++) { > - u32 handle = eb->exec[i].handle; > - struct i915_lut_handle *lut; > +err: > + atomic_dec(&vma->open_count); > + i915_vma_put(vma); > + i915_lut_handle_free(lut); > + return err; > +} > + > +static struct i915_vma *eb_lookup_vma(struct i915_execbuffer *eb, u32 handle) > +{ > + do { > + struct drm_i915_gem_object *obj; > struct i915_vma *vma; > + int err; > > - vma = radix_tree_lookup(handles_vma, handle); > + rcu_read_lock(); > + vma = radix_tree_lookup(&eb->gem_context->handles_vma, handle); > + if (likely(vma)) > + vma = i915_vma_tryget(vma); > + rcu_read_unlock(); > if (likely(vma)) > - goto add_vma; > + return vma; > > obj = i915_gem_object_lookup(eb->file, handle); > - if (unlikely(!obj)) { > - err = -ENOENT; > - goto err_vma; > - } > + if (unlikely(!obj)) > + return ERR_PTR(-ENOENT); > > vma = i915_vma_instance(obj, eb->context->vm, NULL); > if (IS_ERR(vma)) { > - err = PTR_ERR(vma); > - goto err_obj; > + i915_gem_object_put(obj); > + return vma; > } > > - lut = i915_lut_handle_alloc(); > - if (unlikely(!lut)) { > - err = -ENOMEM; > - goto err_obj; > - } > + err = __eb_add_lut(eb, handle, vma); > + if (likely(!err)) > + return vma; > > - err = radix_tree_insert(handles_vma, handle, vma); > - if (unlikely(err)) { > - i915_lut_handle_free(lut); > - goto err_obj; > - } > + i915_gem_object_put(obj); > + if (err != -EEXIST) > + return ERR_PTR(err); > + } while (1); > +} > > - /* transfer ref to lut */ > - if (!atomic_fetch_inc(&vma->open_count)) > - i915_vma_reopen(vma); > - lut->handle = handle; > - lut->ctx = eb->gem_context; > +static int eb_lookup_vmas(struct i915_execbuffer *eb) > +{ > + unsigned int batch = eb_batch_index(eb); > + unsigned int i; > + int err = 0; > > - i915_gem_object_lock(obj); > - list_add(&lut->obj_link, &obj->lut_list); > - i915_gem_object_unlock(obj); > + INIT_LIST_HEAD(&eb->relocs); > + INIT_LIST_HEAD(&eb->unbound); > + > + for (i = 0; i < eb->buffer_count; i++) { > + struct i915_vma *vma; > + > + vma = eb_lookup_vma(eb, eb->exec[i].handle); > + if (IS_ERR(vma)) { > + err = PTR_ERR(vma); > + break; > + } > > -add_vma: > err = eb_validate_vma(eb, &eb->exec[i], vma); > - if (unlikely(err)) > - goto err_vma; > + if (unlikely(err)) { > + i915_vma_put(vma); > + break; > + } > > eb_add_vma(eb, i, batch, vma); > } > > - return 0; > - > -err_obj: > - i915_gem_object_put(obj); > -err_vma: > eb->vma[i].vma = NULL; > return err; > } > @@ -1494,9 +1534,7 @@ static int eb_relocate(struct i915_execbuffer *eb) > { > int err; > > - mutex_lock(&eb->gem_context->mutex); > err = eb_lookup_vmas(eb); > - mutex_unlock(&eb->gem_context->mutex); > if (err) > return err; > > Reviewed-by: Tvrtko Ursulin Regards, Tvrtko _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx