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 06539C433B4 for ; Wed, 28 Apr 2021 16:00:18 +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 80CCA613F0 for ; Wed, 28 Apr 2021 16:00:17 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 80CCA613F0 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 45B146E106; Wed, 28 Apr 2021 16:00:14 +0000 (UTC) Received: from mga07.intel.com (mga07.intel.com [134.134.136.100]) by gabe.freedesktop.org (Postfix) with ESMTPS id 884FC6EBA0; Wed, 28 Apr 2021 15:59:58 +0000 (UTC) IronPort-SDR: Z7v7VEKlz8UM5qq3qv7E68UmPLUzncOcR1o9wceFB0NTMobbDfyDNHXe6le1GkB7SnHRR6hjCR fkeJLx2SqxEA== X-IronPort-AV: E=McAfee;i="6200,9189,9968"; a="260728973" X-IronPort-AV: E=Sophos;i="5.82,258,1613462400"; d="scan'208";a="260728973" Received: from orsmga006.jf.intel.com ([10.7.209.51]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Apr 2021 08:59:57 -0700 IronPort-SDR: 9HdcBqtv7cMTRGS0oLFFDytsOQ4OKqGisNSmf0a/RmjCeiRlMNJdOd/LOJh+xxtmClcS3XLtOY x/pk9j3+ANzQ== X-IronPort-AV: E=Sophos;i="5.82,258,1613462400"; d="scan'208";a="387766020" Received: from akuligox-mobl.ger.corp.intel.com (HELO [10.213.207.221]) ([10.213.207.221]) by orsmga006-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Apr 2021 08:59:56 -0700 Subject: Re: [Intel-gfx] [PATCH 05/21] drm/i915: Drop the CONTEXT_CLONE API To: Jason Ekstrand , intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org References: <20210423223131.879208-1-jason@jlekstrand.net> <20210423223131.879208-6-jason@jlekstrand.net> From: Tvrtko Ursulin Organization: Intel Corporation UK Plc Message-ID: Date: Wed, 28 Apr 2021 16:59:55 +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: <20210423223131.879208-6-jason@jlekstrand.net> Content-Language: en-US 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: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On 23/04/2021 23:31, Jason Ekstrand wrote: > This API allows one context to grab bits out of another context upon > creation. It can be used as a short-cut for setparam(getparam()) for > things like I915_CONTEXT_PARAM_VM. However, it's never been used by any > real userspace. It's used by a few IGT tests and that's it. Since it > doesn't add any real value (most of the stuff you can CLONE you can copy > in other ways), drop it. > > There is one thing that this API allows you to clone which you cannot > clone via getparam/setparam: timelines. However, timelines are an > implementation detail of i915 and not really something that needs to be > exposed to userspace. Also, sharing timelines between contexts isn't > obviously useful and supporting it has the potential to complicate i915 > internally. It also doesn't add any functionality that the client can't > get in other ways. If a client really wants a shared timeline, they can > use a syncobj and set it as an in and out fence on every submit. > > Signed-off-by: Jason Ekstrand > Cc: Tvrtko Ursulin As mentioned before I have no major problem with removing unused uapi apart from disagreeing on when to do it. And the fact I find cloning a very plausible equivalent of clone(2). Which is an established nice model and all. So a sad ack is all I can give. Regards, Tvrtko > --- > drivers/gpu/drm/i915/gem/i915_gem_context.c | 199 +------------------- > include/uapi/drm/i915_drm.h | 16 +- > 2 files changed, 6 insertions(+), 209 deletions(-) > > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c > index 8a77855123cec..2c2fefa912805 100644 > --- a/drivers/gpu/drm/i915/gem/i915_gem_context.c > +++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c > @@ -1958,207 +1958,14 @@ static int create_setparam(struct i915_user_extension __user *ext, void *data) > return ctx_setparam(arg->fpriv, arg->ctx, &local.param); > } > > -static int clone_engines(struct i915_gem_context *dst, > - struct i915_gem_context *src) > +static int invalid_ext(struct i915_user_extension __user *ext, void *data) > { > - struct i915_gem_engines *clone, *e; > - bool user_engines; > - unsigned long n; > - > - e = __context_engines_await(src, &user_engines); > - if (!e) > - return -ENOENT; > - > - clone = alloc_engines(e->num_engines); > - if (!clone) > - goto err_unlock; > - > - for (n = 0; n < e->num_engines; n++) { > - struct intel_engine_cs *engine; > - > - if (!e->engines[n]) { > - clone->engines[n] = NULL; > - continue; > - } > - engine = e->engines[n]->engine; > - > - /* > - * Virtual engines are singletons; they can only exist > - * inside a single context, because they embed their > - * HW context... As each virtual context implies a single > - * timeline (each engine can only dequeue a single request > - * at any time), it would be surprising for two contexts > - * to use the same engine. So let's create a copy of > - * the virtual engine instead. > - */ > - if (intel_engine_is_virtual(engine)) > - clone->engines[n] = > - intel_execlists_clone_virtual(engine); > - else > - clone->engines[n] = intel_context_create(engine); > - if (IS_ERR_OR_NULL(clone->engines[n])) { > - __free_engines(clone, n); > - goto err_unlock; > - } > - > - intel_context_set_gem(clone->engines[n], dst); > - } > - clone->num_engines = n; > - i915_sw_fence_complete(&e->fence); > - > - /* Serialised by constructor */ > - engines_idle_release(dst, rcu_replace_pointer(dst->engines, clone, 1)); > - if (user_engines) > - i915_gem_context_set_user_engines(dst); > - else > - i915_gem_context_clear_user_engines(dst); > - return 0; > - > -err_unlock: > - i915_sw_fence_complete(&e->fence); > - return -ENOMEM; > -} > - > -static int clone_flags(struct i915_gem_context *dst, > - struct i915_gem_context *src) > -{ > - dst->user_flags = src->user_flags; > - return 0; > -} > - > -static int clone_schedattr(struct i915_gem_context *dst, > - struct i915_gem_context *src) > -{ > - dst->sched = src->sched; > - return 0; > -} > - > -static int clone_sseu(struct i915_gem_context *dst, > - struct i915_gem_context *src) > -{ > - struct i915_gem_engines *e = i915_gem_context_lock_engines(src); > - struct i915_gem_engines *clone; > - unsigned long n; > - int err; > - > - /* no locking required; sole access under constructor*/ > - clone = __context_engines_static(dst); > - if (e->num_engines != clone->num_engines) { > - err = -EINVAL; > - goto unlock; > - } > - > - for (n = 0; n < e->num_engines; n++) { > - struct intel_context *ce = e->engines[n]; > - > - if (clone->engines[n]->engine->class != ce->engine->class) { > - /* Must have compatible engine maps! */ > - err = -EINVAL; > - goto unlock; > - } > - > - /* serialises with set_sseu */ > - err = intel_context_lock_pinned(ce); > - if (err) > - goto unlock; > - > - clone->engines[n]->sseu = ce->sseu; > - intel_context_unlock_pinned(ce); > - } > - > - err = 0; > -unlock: > - i915_gem_context_unlock_engines(src); > - return err; > -} > - > -static int clone_timeline(struct i915_gem_context *dst, > - struct i915_gem_context *src) > -{ > - if (src->timeline) > - __assign_timeline(dst, src->timeline); > - > - return 0; > -} > - > -static int clone_vm(struct i915_gem_context *dst, > - struct i915_gem_context *src) > -{ > - struct i915_address_space *vm; > - int err = 0; > - > - if (!rcu_access_pointer(src->vm)) > - return 0; > - > - rcu_read_lock(); > - vm = context_get_vm_rcu(src); > - rcu_read_unlock(); > - > - if (!mutex_lock_interruptible(&dst->mutex)) { > - __assign_ppgtt(dst, vm); > - mutex_unlock(&dst->mutex); > - } else { > - err = -EINTR; > - } > - > - i915_vm_put(vm); > - return err; > -} > - > -static int create_clone(struct i915_user_extension __user *ext, void *data) > -{ > - static int (* const fn[])(struct i915_gem_context *dst, > - struct i915_gem_context *src) = { > -#define MAP(x, y) [ilog2(I915_CONTEXT_CLONE_##x)] = y > - MAP(ENGINES, clone_engines), > - MAP(FLAGS, clone_flags), > - MAP(SCHEDATTR, clone_schedattr), > - MAP(SSEU, clone_sseu), > - MAP(TIMELINE, clone_timeline), > - MAP(VM, clone_vm), > -#undef MAP > - }; > - struct drm_i915_gem_context_create_ext_clone local; > - const struct create_ext *arg = data; > - struct i915_gem_context *dst = arg->ctx; > - struct i915_gem_context *src; > - int err, bit; > - > - if (copy_from_user(&local, ext, sizeof(local))) > - return -EFAULT; > - > - BUILD_BUG_ON(GENMASK(BITS_PER_TYPE(local.flags) - 1, ARRAY_SIZE(fn)) != > - I915_CONTEXT_CLONE_UNKNOWN); > - > - if (local.flags & I915_CONTEXT_CLONE_UNKNOWN) > - return -EINVAL; > - > - if (local.rsvd) > - return -EINVAL; > - > - rcu_read_lock(); > - src = __i915_gem_context_lookup_rcu(arg->fpriv, local.clone_id); > - rcu_read_unlock(); > - if (!src) > - return -ENOENT; > - > - GEM_BUG_ON(src == dst); > - > - for (bit = 0; bit < ARRAY_SIZE(fn); bit++) { > - if (!(local.flags & BIT(bit))) > - continue; > - > - err = fn[bit](dst, src); > - if (err) > - return err; > - } > - > - return 0; > + return -EINVAL; > } > > static const i915_user_extension_fn create_extensions[] = { > [I915_CONTEXT_CREATE_EXT_SETPARAM] = create_setparam, > - [I915_CONTEXT_CREATE_EXT_CLONE] = create_clone, > + [I915_CONTEXT_CREATE_EXT_CLONE] = invalid_ext, > }; > > static bool client_is_banned(struct drm_i915_file_private *file_priv) > diff --git a/include/uapi/drm/i915_drm.h b/include/uapi/drm/i915_drm.h > index a0aaa8298f28d..75a71b6756ed8 100644 > --- a/include/uapi/drm/i915_drm.h > +++ b/include/uapi/drm/i915_drm.h > @@ -1887,20 +1887,10 @@ struct drm_i915_gem_context_create_ext_setparam { > struct drm_i915_gem_context_param param; > }; > > -struct drm_i915_gem_context_create_ext_clone { > +/* This API has been removed. On the off chance someone somewhere has > + * attempted to use it, never re-use this extension number. > + */ > #define I915_CONTEXT_CREATE_EXT_CLONE 1 > - struct i915_user_extension base; > - __u32 clone_id; > - __u32 flags; > -#define I915_CONTEXT_CLONE_ENGINES (1u << 0) > -#define I915_CONTEXT_CLONE_FLAGS (1u << 1) > -#define I915_CONTEXT_CLONE_SCHEDATTR (1u << 2) > -#define I915_CONTEXT_CLONE_SSEU (1u << 3) > -#define I915_CONTEXT_CLONE_TIMELINE (1u << 4) > -#define I915_CONTEXT_CLONE_VM (1u << 5) > -#define I915_CONTEXT_CLONE_UNKNOWN -(I915_CONTEXT_CLONE_VM << 1) > - __u64 rsvd; > -}; > > struct drm_i915_gem_context_destroy { > __u32 ctx_id; > _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel