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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id D1A3CC8302D for ; Thu, 29 Aug 2024 10:14:59 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 96AA010E16C; Thu, 29 Aug 2024 10:14:59 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (1024-bit key; secure) header.d=ffwll.ch header.i=@ffwll.ch header.b="Zueemner"; dkim-atps=neutral Received: from mail-wr1-f50.google.com (mail-wr1-f50.google.com [209.85.221.50]) by gabe.freedesktop.org (Postfix) with ESMTPS id 441B610E16C for ; Thu, 29 Aug 2024 10:14:58 +0000 (UTC) Received: by mail-wr1-f50.google.com with SMTP id ffacd0b85a97d-3717ff2358eso328205f8f.1 for ; Thu, 29 Aug 2024 03:14:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ffwll.ch; s=google; t=1724926496; x=1725531296; darn=lists.freedesktop.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=cOXDolonjvHpVVU7gmdcIHEQfSpycont8Mb+uTTKegg=; b=ZueemnerTApqHS/kwj1v25ZTcnK5RQKLvY0ttpXrMO0+kC14j3V24q7aXwA2I0OBcN 5FOeuV0ykUDt/r/+52ehtzPFeFSzklEU8MlZaT0qnc9l4V/6Jj1lpMEJCGh4CaDyFrlX HxoH+nY1SaJgwKon8Q51oiFUz+j9O+o/s1Acs= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1724926496; x=1725531296; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=cOXDolonjvHpVVU7gmdcIHEQfSpycont8Mb+uTTKegg=; b=awkzVHLl52vjWwFH2YzSDY8NVnEWiy1cM8xQ8m5goCqr75pISpe1RhxJDSkEYlSqqT s1h3f0ZN16yfjBK9J/fa+qlynjsiysIU2HCvuZq8MZGcbVWuP2Yt9wB/5Lvp5uFYw9Be BH7RCwCbcRQKhRjSj0wNYS05XbQ+Efe/ZeOq4BrZ3UieePAcy6Hc27egfw9ZVY+dWaHL 1OVp/4XIBG+j5BwLrYTZX6nyDC3RXAzSD7n52QINdp0GkN2STUUTY3QQA51WVR4x8Hkw +8a8I636AqnZp9jPxmhLBcNtwiXbk/knre7E+fSR5Yak/Ek54EM8NuZ7H1gwPR3PMrtD n2ZQ== X-Gm-Message-State: AOJu0YywNMGUrSLGMn9vCvLaGdfA7TqeTZP3M/NIXOx0Zug/PuM+Ublc CBll0uMN4+Fgda1w0zSRuKoF1+B5KUhp7uoYR9U319OUDh3cTkjZGRaKHgdSQjs= X-Google-Smtp-Source: AGHT+IEFGrDDd+sns+P1BMvkVuGU1BO+GKEI9F3i06qoohpe03oLOtirFvoHiNas211v7bB/12kCrQ== X-Received: by 2002:adf:f74b:0:b0:367:9522:5e6b with SMTP id ffacd0b85a97d-3749b58066bmr1435306f8f.45.1724926496364; Thu, 29 Aug 2024 03:14:56 -0700 (PDT) Received: from phenom.ffwll.local ([2a02:168:57f4:0:5485:d4b2:c087:b497]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-3749ee71b9dsm1016846f8f.38.2024.08.29.03.14.54 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 29 Aug 2024 03:14:55 -0700 (PDT) Date: Thu, 29 Aug 2024 12:14:53 +0200 From: Daniel Vetter To: Matthew Brost Cc: intel-xe@lists.freedesktop.org, dri-devel@lists.freedesktop.org, airlied@gmail.com, christian.koenig@amd.com, thomas.hellstrom@linux.intel.com, matthew.auld@intel.com, daniel@ffwll.ch Subject: Re: [RFC PATCH 24/28] drm/xe: Basic SVM BO eviction Message-ID: References: <20240828024901.2582335-1-matthew.brost@intel.com> <20240828024901.2582335-25-matthew.brost@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240828024901.2582335-25-matthew.brost@intel.com> X-Operating-System: Linux phenom 6.9.12-amd64 X-BeenThere: intel-xe@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel Xe graphics driver List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-xe-bounces@lists.freedesktop.org Sender: "Intel-xe" On Tue, Aug 27, 2024 at 07:48:57PM -0700, Matthew Brost wrote: > Wire xe_bo_move to GPUSVM migration to SRAM with trylocking of mmap > lock. > > Signed-off-by: Matthew Brost > --- > drivers/gpu/drm/xe/xe_bo.c | 35 +++++++++++++++++++++++++++++++- > drivers/gpu/drm/xe/xe_bo_types.h | 3 +++ > drivers/gpu/drm/xe/xe_svm.c | 2 ++ > drivers/gpu/drm/xe/xe_svm.h | 13 ++++++++++++ > 4 files changed, 52 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/xe/xe_bo.c b/drivers/gpu/drm/xe/xe_bo.c > index ad804b6f9e84..ae71fcbe5380 100644 > --- a/drivers/gpu/drm/xe/xe_bo.c > +++ b/drivers/gpu/drm/xe/xe_bo.c > @@ -25,6 +25,7 @@ > #include "xe_pm.h" > #include "xe_preempt_fence.h" > #include "xe_res_cursor.h" > +#include "xe_svm.h" > #include "xe_trace_bo.h" > #include "xe_ttm_stolen_mgr.h" > #include "xe_vm.h" > @@ -250,6 +251,8 @@ int xe_bo_placement_for_flags(struct xe_device *xe, struct xe_bo *bo, > static void xe_evict_flags(struct ttm_buffer_object *tbo, > struct ttm_placement *placement) > { > + struct xe_bo *bo; > + > if (!xe_bo_is_xe_bo(tbo)) { > /* Don't handle scatter gather BOs */ > if (tbo->type == ttm_bo_type_sg) { > @@ -261,6 +264,12 @@ static void xe_evict_flags(struct ttm_buffer_object *tbo, > return; > } > > + bo = ttm_to_xe_bo(tbo); > + if (bo->flags & XE_BO_FLAG_SYSTEM_ALLOC) { > + *placement = sys_placement; > + return; > + } > + > /* > * For xe, sg bos that are evicted to system just triggers a > * rebind of the sg list upon subsequent validation to XE_PL_TT. > @@ -758,6 +767,17 @@ static int xe_bo_move(struct ttm_buffer_object *ttm_bo, bool evict, > } > } > > + if (!move_lacks_source && (bo->flags & XE_BO_FLAG_SYSTEM_ALLOC) && > + new_mem->mem_type == XE_PL_SYSTEM) { > + ret = xe_svm_range_evict(bo->range); > + if (!ret) { > + drm_dbg(&xe->drm, "Evict system allocator BO success\n"); > + ttm_bo_move_null(ttm_bo, new_mem); > + } > + > + goto out; > + } > + > if (!move_lacks_source && > ((old_mem_type == XE_PL_SYSTEM && resource_is_vram(new_mem)) || > (mem_type_is_vram(old_mem_type) && > @@ -1096,6 +1116,19 @@ static void xe_ttm_bo_delete_mem_notify(struct ttm_buffer_object *ttm_bo) > } > } > > +static bool xe_bo_eviction_valuable(struct ttm_buffer_object *ttm_bo, > + const struct ttm_place *place) > +{ > + struct xe_bo *bo = ttm_to_xe_bo(ttm_bo); > + > + /* Do not evict SVMs before having a binding */ > + if (bo->flags & XE_BO_FLAG_SYSTEM_ALLOC && > + !xe_svm_range_has_vram_binding(bo->range)) > + return false; > + > + return ttm_bo_eviction_valuable(ttm_bo, place); > +} > + > const struct ttm_device_funcs xe_ttm_funcs = { > .ttm_tt_create = xe_ttm_tt_create, > .ttm_tt_populate = xe_ttm_tt_populate, > @@ -1106,7 +1139,7 @@ const struct ttm_device_funcs xe_ttm_funcs = { > .io_mem_reserve = xe_ttm_io_mem_reserve, > .io_mem_pfn = xe_ttm_io_mem_pfn, > .release_notify = xe_ttm_bo_release_notify, > - .eviction_valuable = ttm_bo_eviction_valuable, > + .eviction_valuable = xe_bo_eviction_valuable, > .delete_mem_notify = xe_ttm_bo_delete_mem_notify, > }; > > diff --git a/drivers/gpu/drm/xe/xe_bo_types.h b/drivers/gpu/drm/xe/xe_bo_types.h > index 2ed558ac2264..4523b033417c 100644 > --- a/drivers/gpu/drm/xe/xe_bo_types.h > +++ b/drivers/gpu/drm/xe/xe_bo_types.h > @@ -16,6 +16,7 @@ > #include "xe_ggtt_types.h" > > struct xe_device; > +struct xe_svm_range; > struct xe_vm; > > #define XE_BO_MAX_PLACEMENTS 3 > @@ -47,6 +48,8 @@ struct xe_bo { > struct ttm_bo_kmap_obj kmap; > /** @pinned_link: link to present / evicted list of pinned BO */ > struct list_head pinned_link; > + /** @range: SVM range for BO */ > + struct xe_svm_range *range; > #ifdef CONFIG_PROC_FS > /** > * @client: @xe_drm_client which created the bo > diff --git a/drivers/gpu/drm/xe/xe_svm.c b/drivers/gpu/drm/xe/xe_svm.c > index fd8987e0a506..dc9810828c0a 100644 > --- a/drivers/gpu/drm/xe/xe_svm.c > +++ b/drivers/gpu/drm/xe/xe_svm.c > @@ -531,6 +531,8 @@ static struct xe_bo *xe_svm_alloc_vram(struct xe_vm *vm, struct xe_tile *tile, > range->base.va.start, ttm_bo_type_device, > XE_BO_FLAG_VRAM_IF_DGFX(tile) | > XE_BO_FLAG_SYSTEM_ALLOC | XE_BO_FLAG_SKIP_CLEAR); > + if (!IS_ERR(bo)) > + bo->range = range; > xe_vm_unlock(vm); > if (IS_ERR(bo)) { > err = PTR_ERR(bo); > diff --git a/drivers/gpu/drm/xe/xe_svm.h b/drivers/gpu/drm/xe/xe_svm.h > index 3f432483a230..b9cf0e2500da 100644 > --- a/drivers/gpu/drm/xe/xe_svm.h > +++ b/drivers/gpu/drm/xe/xe_svm.h > @@ -46,6 +46,19 @@ static inline bool xe_svm_range_has_dma_mapping(struct xe_svm_range *range) > return range->base.flags.has_dma_mapping; > } > > +static inline bool xe_svm_range_has_vram_binding(struct xe_svm_range *range) > +{ > + return xe_svm_range_in_vram(range) && range->tile_present; > +} > + > +static inline int xe_svm_range_evict(struct xe_svm_range *range) > +{ > + struct drm_gpusvm_ctx ctx = { .trylock_mmap = true, }; So even trying to acquire an mmap lock for eviction is I think a design bug for svm memory ranges. It's a bunch of physical memory, you have no idea how many mm/vma map it and which one you pick as the special one is fairly arbitrary. So dont, eviction should entirely ignore va/mm issues at the top level like the migrate_device_range function does (maybe we need a scatter-gather version of that instead of just a range. That function internally makes sure you're in sync with any vma/vm by: - installing migration ptes everywhere, which does the mmu_notifer dance - locking the pages to prevent other concurrent migration or other fun stuff from happening - then restore ptes to something sensisble when it's all done And it does that by looping over _all_ possible mappings of a page with the rmap_walk infrastructure. The only reason when we need the mmap lock (or vma lock or whatever) is if we need to be coherent with other concurrent mm updates of a specific mm. That should only be the case when migrating to vram, where the gpusvm->mm is the special one, and when migrating to sram due to cpu faults, where the vmf->vma->mm is special (and might at best have a tenous relationship to the gpusvm->mm). But that's the only cases where a specific mm and vma have any relevance to svm vram allocations. -Sima > + > + return drm_gpusvm_migrate_to_sram(range->base.gpusvm, &range->base, > + &ctx); > +} > + > #define xe_svm_notifier_lock(vm__) \ > drm_gpusvm_notifier_lock(&(vm__)->svm.gpusvm) > > -- > 2.34.1 > -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch