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=-13.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 AFC80C433B4 for ; Wed, 28 Apr 2021 17:26:35 +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 2D662613D8 for ; Wed, 28 Apr 2021 17:26:35 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2D662613D8 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=jlekstrand.net 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 4F8426E150; Wed, 28 Apr 2021 17:26:34 +0000 (UTC) Received: from mail-ed1-x52f.google.com (mail-ed1-x52f.google.com [IPv6:2a00:1450:4864:20::52f]) by gabe.freedesktop.org (Postfix) with ESMTPS id 594CF6E150 for ; Wed, 28 Apr 2021 17:26:24 +0000 (UTC) Received: by mail-ed1-x52f.google.com with SMTP id n25so3130309edr.5 for ; Wed, 28 Apr 2021 10:26:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=jlekstrand-net.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=3WVHBRre3pKfaieyTeImbVdoeE0zfCBlpO7OTVHm8mc=; b=ecRqmB3IYycGqRNZL0elurXjYfmxwdGEBq2nLLnm9RBQ1nLai/82nuugKjzCo9eXEk QgWp0lUFtzgD3pcNQnwJ0dh5WmPeJzAiea5t47CGl7RIhkRYx3bAST7cn90Dq9k4uha+ uN4CmsgSMe3wbmAHFKBC7BUwuTuVBxMIUeJkfDyLFixV+nKsfUwcPLF9Iv4EIkHGYcVA IJeCzg5sRd821afTa70tZgiHaORQI3uRjHDmfhSu9IU5+lcAarDjz3sipdhizSKptPo3 hvHNXM2jbXBcjPQGtMdxP81conxcxJnVbuUDyySewdSwwprGHXB3g040IJLnCzFHMk5t bpMA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=3WVHBRre3pKfaieyTeImbVdoeE0zfCBlpO7OTVHm8mc=; b=WC0WUBctiFoXFTMqmrdcSWSTGNTlyqYi8QHd7tKqUBnx/ioPRcrtTyRDPORL/QKVOW DxnS7o7+QWdAoiL+uldp0HVLhM6+EL7PE2pE6PbU/2l7L0GiPkLQcpj8HmhfqT0D9FeB LFKsO3GdU2o9i4h0L0PUREYKGPOR1qIRqoV5KWACQ16MINHALZA/TnU0mxK6suhQLksl Zap5GG8zYp0CL/fbi/Q4TSU7DmjlndyPdc6QWJ1onk4V8ui2GVb+PM+mF0Wrmz+ELD01 c6g+J48DBbT+Tsvt916BUuo9jkJr29/ebSbAIUv0YFoTTAxq7rUyKH2cL9WE5MzfsJ9Q Zxyw== X-Gm-Message-State: AOAM530e+rv0b15qaRl/6mkOZ1y9+rcMrhZFaSF4aIy7T1JbRiisxBXu 16DXabdJ4Yam9GvLrl7bWX1aoEpBr+jLj9+IkdesQw== X-Google-Smtp-Source: ABdhPJygXCEJ2ifVkoQ55B9T6DMnnvrFbsDCV/ZF34ksl7PdB/tvT9N1b0Ez5LoxaHY33ZwBGJN0eJ05koq7RjRRtck= X-Received: by 2002:aa7:c049:: with SMTP id k9mr12670814edo.56.1619630782672; Wed, 28 Apr 2021 10:26:22 -0700 (PDT) MIME-Version: 1.0 References: <20210423223131.879208-1-jason@jlekstrand.net> <20210423223131.879208-7-jason@jlekstrand.net> In-Reply-To: From: Jason Ekstrand Date: Wed, 28 Apr 2021 12:26:11 -0500 Message-ID: Subject: Re: [Intel-gfx] [PATCH 06/21] drm/i915: Implement SINGLE_TIMELINE with a syncobj (v3) To: Tvrtko Ursulin 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: Intel GFX , Maling list - DRI developers Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On Wed, Apr 28, 2021 at 10:49 AM Tvrtko Ursulin wrote: > > > On 23/04/2021 23:31, Jason Ekstrand wrote: > > This API is entirely unnecessary and I'd love to get rid of it. If > > userspace wants a single timeline across multiple contexts, they can > > either use implicit synchronization or a syncobj, both of which existed > > at the time this feature landed. The justification given at the time > > was that it would help GL drivers which are inherently single-timeline. > > However, neither of our GL drivers actually wanted the feature. i965 > > was already in maintenance mode at the time and iris uses syncobj for > > everything. > > > > Unfortunately, as much as I'd love to get rid of it, it is used by the > > media driver so we can't do that. We can, however, do the next-best > > thing which is to embed a syncobj in the context and do exactly what > > we'd expect from userspace internally. This isn't an entirely identical > > implementation because it's no longer atomic if userspace races with > > itself by calling execbuffer2 twice simultaneously from different > > threads. It won't crash in that case; it just doesn't guarantee any > > ordering between those two submits. > > 1) > > Please also mention the difference in context/timeline name when > observed via the sync file API. > > 2) > > I don't remember what we have concluded in terms of observable effects > in sync_file_merge? I don't see how either of these are observable since this syncobj is never exposed to userspace in any way. Please help me understand what I'm missing here. --Jason > Regards, > > Tvrtko > > > Moving SINGLE_TIMELINE to a syncobj emulation has a couple of technical > > advantages beyond mere annoyance. One is that intel_timeline is no > > longer an api-visible object and can remain entirely an implementation > > detail. This may be advantageous as we make scheduler changes going > > forward. Second is that, together with deleting the CLONE_CONTEXT API, > > we should now have a 1:1 mapping between intel_context and > > intel_timeline which may help us reduce locking. > > > > v2 (Jason Ekstrand): > > - Update the comment on i915_gem_context::syncobj to mention that it's > > an emulation and the possible race if userspace calls execbuffer2 > > twice on the same context concurrently. > > - Wrap the checks for eb.gem_context->syncobj in unlikely() > > - Drop the dma_fence reference > > - Improved commit message > > > > v3 (Jason Ekstrand): > > - Move the dma_fence_put() to before the error exit > > > > Signed-off-by: Jason Ekstrand > > Cc: Maarten Lankhorst > > Cc: Matthew Brost > > --- > > drivers/gpu/drm/i915/gem/i915_gem_context.c | 49 +++++-------------- > > .../gpu/drm/i915/gem/i915_gem_context_types.h | 14 +++++- > > .../gpu/drm/i915/gem/i915_gem_execbuffer.c | 16 ++++++ > > 3 files changed, 40 insertions(+), 39 deletions(-) > > > > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c > > index 2c2fefa912805..a72c9b256723b 100644 > > --- a/drivers/gpu/drm/i915/gem/i915_gem_context.c > > +++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c > > @@ -67,6 +67,8 @@ > > #include > > #include > > > > +#include > > + > > #include "gt/gen6_ppgtt.h" > > #include "gt/intel_context.h" > > #include "gt/intel_context_param.h" > > @@ -225,10 +227,6 @@ static void intel_context_set_gem(struct intel_context *ce, > > ce->vm = vm; > > } > > > > - GEM_BUG_ON(ce->timeline); > > - if (ctx->timeline) > > - ce->timeline = intel_timeline_get(ctx->timeline); > > - > > if (ctx->sched.priority >= I915_PRIORITY_NORMAL && > > intel_engine_has_timeslices(ce->engine)) > > __set_bit(CONTEXT_USE_SEMAPHORES, &ce->flags); > > @@ -351,9 +349,6 @@ void i915_gem_context_release(struct kref *ref) > > mutex_destroy(&ctx->engines_mutex); > > mutex_destroy(&ctx->lut_mutex); > > > > - if (ctx->timeline) > > - intel_timeline_put(ctx->timeline); > > - > > put_pid(ctx->pid); > > mutex_destroy(&ctx->mutex); > > > > @@ -570,6 +565,9 @@ static void context_close(struct i915_gem_context *ctx) > > if (vm) > > i915_vm_close(vm); > > > > + if (ctx->syncobj) > > + drm_syncobj_put(ctx->syncobj); > > + > > ctx->file_priv = ERR_PTR(-EBADF); > > > > /* > > @@ -765,33 +763,11 @@ static void __assign_ppgtt(struct i915_gem_context *ctx, > > i915_vm_close(vm); > > } > > > > -static void __set_timeline(struct intel_timeline **dst, > > - struct intel_timeline *src) > > -{ > > - struct intel_timeline *old = *dst; > > - > > - *dst = src ? intel_timeline_get(src) : NULL; > > - > > - if (old) > > - intel_timeline_put(old); > > -} > > - > > -static void __apply_timeline(struct intel_context *ce, void *timeline) > > -{ > > - __set_timeline(&ce->timeline, timeline); > > -} > > - > > -static void __assign_timeline(struct i915_gem_context *ctx, > > - struct intel_timeline *timeline) > > -{ > > - __set_timeline(&ctx->timeline, timeline); > > - context_apply_all(ctx, __apply_timeline, timeline); > > -} > > - > > static struct i915_gem_context * > > i915_gem_create_context(struct drm_i915_private *i915, unsigned int flags) > > { > > struct i915_gem_context *ctx; > > + int ret; > > > > if (flags & I915_CONTEXT_CREATE_FLAGS_SINGLE_TIMELINE && > > !HAS_EXECLISTS(i915)) > > @@ -820,16 +796,13 @@ i915_gem_create_context(struct drm_i915_private *i915, unsigned int flags) > > } > > > > if (flags & I915_CONTEXT_CREATE_FLAGS_SINGLE_TIMELINE) { > > - struct intel_timeline *timeline; > > - > > - timeline = intel_timeline_create(&i915->gt); > > - if (IS_ERR(timeline)) { > > + ret = drm_syncobj_create(&ctx->syncobj, > > + DRM_SYNCOBJ_CREATE_SIGNALED, > > + NULL); > > + if (ret) { > > context_close(ctx); > > - return ERR_CAST(timeline); > > + return ERR_PTR(ret); > > } > > - > > - __assign_timeline(ctx, timeline); > > - intel_timeline_put(timeline); > > } > > > > trace_i915_context_create(ctx); > > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context_types.h b/drivers/gpu/drm/i915/gem/i915_gem_context_types.h > > index 676592e27e7d2..df76767f0c41b 100644 > > --- a/drivers/gpu/drm/i915/gem/i915_gem_context_types.h > > +++ b/drivers/gpu/drm/i915/gem/i915_gem_context_types.h > > @@ -83,7 +83,19 @@ struct i915_gem_context { > > struct i915_gem_engines __rcu *engines; > > struct mutex engines_mutex; /* guards writes to engines */ > > > > - struct intel_timeline *timeline; > > + /** > > + * @syncobj: Shared timeline syncobj > > + * > > + * When the SHARED_TIMELINE flag is set on context creation, we > > + * emulate a single timeline across all engines using this syncobj. > > + * For every execbuffer2 call, this syncobj is used as both an in- > > + * and out-fence. Unlike the real intel_timeline, this doesn't > > + * provide perfect atomic in-order guarantees if the client races > > + * with itself by calling execbuffer2 twice concurrently. However, > > + * if userspace races with itself, that's not likely to yield well- > > + * defined results anyway so we choose to not care. > > + */ > > + struct drm_syncobj *syncobj; > > > > /** > > * @vm: unique address space (GTT) > > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c > > index b812f313422a9..d640bba6ad9ab 100644 > > --- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c > > +++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c > > @@ -3460,6 +3460,16 @@ i915_gem_do_execbuffer(struct drm_device *dev, > > goto err_vma; > > } > > > > + if (unlikely(eb.gem_context->syncobj)) { > > + struct dma_fence *fence; > > + > > + fence = drm_syncobj_fence_get(eb.gem_context->syncobj); > > + err = i915_request_await_dma_fence(eb.request, fence); > > + dma_fence_put(fence); > > + if (err) > > + goto err_ext; > > + } > > + > > if (in_fence) { > > if (args->flags & I915_EXEC_FENCE_SUBMIT) > > err = i915_request_await_execution(eb.request, > > @@ -3517,6 +3527,12 @@ i915_gem_do_execbuffer(struct drm_device *dev, > > fput(out_fence->file); > > } > > } > > + > > + if (unlikely(eb.gem_context->syncobj)) { > > + drm_syncobj_replace_fence(eb.gem_context->syncobj, > > + &eb.request->fence); > > + } > > + > > i915_request_put(eb.request); > > > > err_vma: > > _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel 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=-13.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,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 0AC5DC433B4 for ; Wed, 28 Apr 2021 17:26:27 +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 8DAC76143A for ; Wed, 28 Apr 2021 17:26:26 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8DAC76143A Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=jlekstrand.net 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 B022A89CB5; Wed, 28 Apr 2021 17:26:25 +0000 (UTC) Received: from mail-ed1-x534.google.com (mail-ed1-x534.google.com [IPv6:2a00:1450:4864:20::534]) by gabe.freedesktop.org (Postfix) with ESMTPS id 3DE7989CB5 for ; Wed, 28 Apr 2021 17:26:24 +0000 (UTC) Received: by mail-ed1-x534.google.com with SMTP id s15so75263482edd.4 for ; Wed, 28 Apr 2021 10:26:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=jlekstrand-net.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=3WVHBRre3pKfaieyTeImbVdoeE0zfCBlpO7OTVHm8mc=; b=ecRqmB3IYycGqRNZL0elurXjYfmxwdGEBq2nLLnm9RBQ1nLai/82nuugKjzCo9eXEk QgWp0lUFtzgD3pcNQnwJ0dh5WmPeJzAiea5t47CGl7RIhkRYx3bAST7cn90Dq9k4uha+ uN4CmsgSMe3wbmAHFKBC7BUwuTuVBxMIUeJkfDyLFixV+nKsfUwcPLF9Iv4EIkHGYcVA IJeCzg5sRd821afTa70tZgiHaORQI3uRjHDmfhSu9IU5+lcAarDjz3sipdhizSKptPo3 hvHNXM2jbXBcjPQGtMdxP81conxcxJnVbuUDyySewdSwwprGHXB3g040IJLnCzFHMk5t bpMA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=3WVHBRre3pKfaieyTeImbVdoeE0zfCBlpO7OTVHm8mc=; b=rP8X2u0jTab3vKLHhaFZuAsJcc6kuPAtuUqoW8EPdbQSagHTx2AQKCs4V5ab0TvlY3 3ouescWY7xk7emFcyZnvNeHTUOwdT+lSFEvX1d+oCjZ6tONmohnXGtURFXpojPJcPUdu VhU44g4rA5e93lN5JlEWu4ElNnMojUMREniEtjnvNBeFUj1ynAfQKDFtwItFfCJEj+OX BNpKrCi83pgpYZNrwUNEjvhLoRplvX9mY8CIMFI4+BVEXV6ckjsXAY4CIweDGLBm9E4m e/k4L35ot4j2MXmtNzvKeYsd+IzEJ0JiM1tlAuP1iOuyKifX1hGdsg2H7M5rxIUhYaJt zy0A== X-Gm-Message-State: AOAM533Yho4OAMN1cuYZ/pAA9sBYUE405ofde0mw77N12NyQDFl6Mlwt ekx8+KuDEBLpnp9wSZM9LBD1ddS2OaVpYSPGcd4ABA== X-Google-Smtp-Source: ABdhPJygXCEJ2ifVkoQ55B9T6DMnnvrFbsDCV/ZF34ksl7PdB/tvT9N1b0Ez5LoxaHY33ZwBGJN0eJ05koq7RjRRtck= X-Received: by 2002:aa7:c049:: with SMTP id k9mr12670814edo.56.1619630782672; Wed, 28 Apr 2021 10:26:22 -0700 (PDT) MIME-Version: 1.0 References: <20210423223131.879208-1-jason@jlekstrand.net> <20210423223131.879208-7-jason@jlekstrand.net> In-Reply-To: From: Jason Ekstrand Date: Wed, 28 Apr 2021 12:26:11 -0500 Message-ID: To: Tvrtko Ursulin Subject: Re: [Intel-gfx] [PATCH 06/21] drm/i915: Implement SINGLE_TIMELINE with a syncobj (v3) 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: Intel GFX , Maling list - DRI developers Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" On Wed, Apr 28, 2021 at 10:49 AM Tvrtko Ursulin wrote: > > > On 23/04/2021 23:31, Jason Ekstrand wrote: > > This API is entirely unnecessary and I'd love to get rid of it. If > > userspace wants a single timeline across multiple contexts, they can > > either use implicit synchronization or a syncobj, both of which existed > > at the time this feature landed. The justification given at the time > > was that it would help GL drivers which are inherently single-timeline. > > However, neither of our GL drivers actually wanted the feature. i965 > > was already in maintenance mode at the time and iris uses syncobj for > > everything. > > > > Unfortunately, as much as I'd love to get rid of it, it is used by the > > media driver so we can't do that. We can, however, do the next-best > > thing which is to embed a syncobj in the context and do exactly what > > we'd expect from userspace internally. This isn't an entirely identical > > implementation because it's no longer atomic if userspace races with > > itself by calling execbuffer2 twice simultaneously from different > > threads. It won't crash in that case; it just doesn't guarantee any > > ordering between those two submits. > > 1) > > Please also mention the difference in context/timeline name when > observed via the sync file API. > > 2) > > I don't remember what we have concluded in terms of observable effects > in sync_file_merge? I don't see how either of these are observable since this syncobj is never exposed to userspace in any way. Please help me understand what I'm missing here. --Jason > Regards, > > Tvrtko > > > Moving SINGLE_TIMELINE to a syncobj emulation has a couple of technical > > advantages beyond mere annoyance. One is that intel_timeline is no > > longer an api-visible object and can remain entirely an implementation > > detail. This may be advantageous as we make scheduler changes going > > forward. Second is that, together with deleting the CLONE_CONTEXT API, > > we should now have a 1:1 mapping between intel_context and > > intel_timeline which may help us reduce locking. > > > > v2 (Jason Ekstrand): > > - Update the comment on i915_gem_context::syncobj to mention that it's > > an emulation and the possible race if userspace calls execbuffer2 > > twice on the same context concurrently. > > - Wrap the checks for eb.gem_context->syncobj in unlikely() > > - Drop the dma_fence reference > > - Improved commit message > > > > v3 (Jason Ekstrand): > > - Move the dma_fence_put() to before the error exit > > > > Signed-off-by: Jason Ekstrand > > Cc: Maarten Lankhorst > > Cc: Matthew Brost > > --- > > drivers/gpu/drm/i915/gem/i915_gem_context.c | 49 +++++-------------- > > .../gpu/drm/i915/gem/i915_gem_context_types.h | 14 +++++- > > .../gpu/drm/i915/gem/i915_gem_execbuffer.c | 16 ++++++ > > 3 files changed, 40 insertions(+), 39 deletions(-) > > > > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c > > index 2c2fefa912805..a72c9b256723b 100644 > > --- a/drivers/gpu/drm/i915/gem/i915_gem_context.c > > +++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c > > @@ -67,6 +67,8 @@ > > #include > > #include > > > > +#include > > + > > #include "gt/gen6_ppgtt.h" > > #include "gt/intel_context.h" > > #include "gt/intel_context_param.h" > > @@ -225,10 +227,6 @@ static void intel_context_set_gem(struct intel_context *ce, > > ce->vm = vm; > > } > > > > - GEM_BUG_ON(ce->timeline); > > - if (ctx->timeline) > > - ce->timeline = intel_timeline_get(ctx->timeline); > > - > > if (ctx->sched.priority >= I915_PRIORITY_NORMAL && > > intel_engine_has_timeslices(ce->engine)) > > __set_bit(CONTEXT_USE_SEMAPHORES, &ce->flags); > > @@ -351,9 +349,6 @@ void i915_gem_context_release(struct kref *ref) > > mutex_destroy(&ctx->engines_mutex); > > mutex_destroy(&ctx->lut_mutex); > > > > - if (ctx->timeline) > > - intel_timeline_put(ctx->timeline); > > - > > put_pid(ctx->pid); > > mutex_destroy(&ctx->mutex); > > > > @@ -570,6 +565,9 @@ static void context_close(struct i915_gem_context *ctx) > > if (vm) > > i915_vm_close(vm); > > > > + if (ctx->syncobj) > > + drm_syncobj_put(ctx->syncobj); > > + > > ctx->file_priv = ERR_PTR(-EBADF); > > > > /* > > @@ -765,33 +763,11 @@ static void __assign_ppgtt(struct i915_gem_context *ctx, > > i915_vm_close(vm); > > } > > > > -static void __set_timeline(struct intel_timeline **dst, > > - struct intel_timeline *src) > > -{ > > - struct intel_timeline *old = *dst; > > - > > - *dst = src ? intel_timeline_get(src) : NULL; > > - > > - if (old) > > - intel_timeline_put(old); > > -} > > - > > -static void __apply_timeline(struct intel_context *ce, void *timeline) > > -{ > > - __set_timeline(&ce->timeline, timeline); > > -} > > - > > -static void __assign_timeline(struct i915_gem_context *ctx, > > - struct intel_timeline *timeline) > > -{ > > - __set_timeline(&ctx->timeline, timeline); > > - context_apply_all(ctx, __apply_timeline, timeline); > > -} > > - > > static struct i915_gem_context * > > i915_gem_create_context(struct drm_i915_private *i915, unsigned int flags) > > { > > struct i915_gem_context *ctx; > > + int ret; > > > > if (flags & I915_CONTEXT_CREATE_FLAGS_SINGLE_TIMELINE && > > !HAS_EXECLISTS(i915)) > > @@ -820,16 +796,13 @@ i915_gem_create_context(struct drm_i915_private *i915, unsigned int flags) > > } > > > > if (flags & I915_CONTEXT_CREATE_FLAGS_SINGLE_TIMELINE) { > > - struct intel_timeline *timeline; > > - > > - timeline = intel_timeline_create(&i915->gt); > > - if (IS_ERR(timeline)) { > > + ret = drm_syncobj_create(&ctx->syncobj, > > + DRM_SYNCOBJ_CREATE_SIGNALED, > > + NULL); > > + if (ret) { > > context_close(ctx); > > - return ERR_CAST(timeline); > > + return ERR_PTR(ret); > > } > > - > > - __assign_timeline(ctx, timeline); > > - intel_timeline_put(timeline); > > } > > > > trace_i915_context_create(ctx); > > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context_types.h b/drivers/gpu/drm/i915/gem/i915_gem_context_types.h > > index 676592e27e7d2..df76767f0c41b 100644 > > --- a/drivers/gpu/drm/i915/gem/i915_gem_context_types.h > > +++ b/drivers/gpu/drm/i915/gem/i915_gem_context_types.h > > @@ -83,7 +83,19 @@ struct i915_gem_context { > > struct i915_gem_engines __rcu *engines; > > struct mutex engines_mutex; /* guards writes to engines */ > > > > - struct intel_timeline *timeline; > > + /** > > + * @syncobj: Shared timeline syncobj > > + * > > + * When the SHARED_TIMELINE flag is set on context creation, we > > + * emulate a single timeline across all engines using this syncobj. > > + * For every execbuffer2 call, this syncobj is used as both an in- > > + * and out-fence. Unlike the real intel_timeline, this doesn't > > + * provide perfect atomic in-order guarantees if the client races > > + * with itself by calling execbuffer2 twice concurrently. However, > > + * if userspace races with itself, that's not likely to yield well- > > + * defined results anyway so we choose to not care. > > + */ > > + struct drm_syncobj *syncobj; > > > > /** > > * @vm: unique address space (GTT) > > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c > > index b812f313422a9..d640bba6ad9ab 100644 > > --- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c > > +++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c > > @@ -3460,6 +3460,16 @@ i915_gem_do_execbuffer(struct drm_device *dev, > > goto err_vma; > > } > > > > + if (unlikely(eb.gem_context->syncobj)) { > > + struct dma_fence *fence; > > + > > + fence = drm_syncobj_fence_get(eb.gem_context->syncobj); > > + err = i915_request_await_dma_fence(eb.request, fence); > > + dma_fence_put(fence); > > + if (err) > > + goto err_ext; > > + } > > + > > if (in_fence) { > > if (args->flags & I915_EXEC_FENCE_SUBMIT) > > err = i915_request_await_execution(eb.request, > > @@ -3517,6 +3527,12 @@ i915_gem_do_execbuffer(struct drm_device *dev, > > fput(out_fence->file); > > } > > } > > + > > + if (unlikely(eb.gem_context->syncobj)) { > > + drm_syncobj_replace_fence(eb.gem_context->syncobj, > > + &eb.request->fence); > > + } > > + > > i915_request_put(eb.request); > > > > err_vma: > > _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx