Re: [Intel-gfx] [PATCH 6/6] drm/i915: Avoid allocating a vmap arena for a single page
On 06/04/16 11:05, Chris Wilson wrote: On Wed, Apr 06, 2016 at 10:49:36AM +0100, Tvrtko Ursulin wrote: diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 985f067c1f0e..dc8e1b76c896 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -2233,7 +2233,10 @@ i915_gem_object_put_pages(struct drm_i915_gem_object *obj) list_del(>global_list); if (obj->vmapping) { - vunmap(obj->vmapping); + if (obj->base.size == PAGE_SIZE) + kunmap(kmap_to_page(obj->vmapping)); + else + vunmap(obj->vmapping); Can't think of a reason why it would be better but there is also is_vmalloc_addr(addr) as used by kvfree. For consistency with the shrinker (see below). What I don't like here is the repetition (and correlation) of the PAGE_SIZE test, which has to be kept in sync with the corresponding one at the point where the mapping was set up. If we're going to overload the same field to store two different types of mapping, there should be an explicit flag to say which we chose. Or failing that, then actually test the mapping itself (as in is_vmalloc_addr()). obj->vmapping = NULL; } @@ -2416,15 +2419,22 @@ void *i915_gem_object_pin_vmap(struct drm_i915_gem_object *obj) i915_gem_object_pin_pages(obj); if (obj->vmapping == NULL) { - struct sg_page_iter sg_iter; struct page **pages; - int n; - n = obj->base.size >> PAGE_SHIFT; - pages = drm_malloc_gfp(n, sizeof(*pages), GFP_TEMPORARY); + pages = NULL; + if (obj->base.size == PAGE_SIZE) + obj->vmapping = kmap(sg_page(obj->pages->sgl)); + else + pages = drm_malloc_gfp(obj->base.size >> PAGE_SHIFT, + sizeof(*pages), + GFP_TEMPORARY); if (pages != NULL) { + struct sg_page_iter sg_iter; + int n; + n = 0; - for_each_sg_page(obj->pages->sgl, _iter, obj->pages->nents, 0) + for_each_sg_page(obj->pages->sgl, _iter, +obj->pages->nents, 0) pages[n++] = sg_page_iter_page(_iter); obj->vmapping = vmap(pages, n, 0, PAGE_KERNEL); Two problems I can spot are: 1. Callers of pin_vmap now don't know which kind of address they are getting. Maybe call it pin_kvmap or something? Just mention in kerneldoc could be enough. I think just mention, and we can rename this to i915_gem_object_pin_map(). Hmm. I liked the pin in the name since it ties to to pin_pages (later I plan to change that to get_pages and get_vmap/get_map as the pin becomes implicit). 2. Shrinker will try to kick out kmapped objects because they have obj->vmapping set. Not caring that much since the vmap_purge is very heavy weight, but we can apply is_vmalloc_addr() to the shrinker. Ok, happy to call this obj->mapping and i915_gem_object_pin_map() ? -Chris Quite happy with the rename, and returning either type (a (virtual) address is just an address), but not with the implementation repeating the decision code. .Dave. ___ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx
Re: [Intel-gfx] [PATCH 6/6] drm/i915: Avoid allocating a vmap arena for a single page
On 06/04/16 11:05, Chris Wilson wrote: On Wed, Apr 06, 2016 at 10:49:36AM +0100, Tvrtko Ursulin wrote: diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 985f067c1f0e..dc8e1b76c896 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -2233,7 +2233,10 @@ i915_gem_object_put_pages(struct drm_i915_gem_object *obj) list_del(>global_list); if (obj->vmapping) { - vunmap(obj->vmapping); + if (obj->base.size == PAGE_SIZE) + kunmap(kmap_to_page(obj->vmapping)); + else + vunmap(obj->vmapping); Can't think of a reason why it would be better but there is also is_vmalloc_addr(addr) as used by kvfree. For consistency with the shrinker (see below). obj->vmapping = NULL; } @@ -2416,15 +2419,22 @@ void *i915_gem_object_pin_vmap(struct drm_i915_gem_object *obj) i915_gem_object_pin_pages(obj); if (obj->vmapping == NULL) { - struct sg_page_iter sg_iter; struct page **pages; - int n; - n = obj->base.size >> PAGE_SHIFT; - pages = drm_malloc_gfp(n, sizeof(*pages), GFP_TEMPORARY); + pages = NULL; + if (obj->base.size == PAGE_SIZE) + obj->vmapping = kmap(sg_page(obj->pages->sgl)); + else + pages = drm_malloc_gfp(obj->base.size >> PAGE_SHIFT, + sizeof(*pages), + GFP_TEMPORARY); if (pages != NULL) { + struct sg_page_iter sg_iter; + int n; + n = 0; - for_each_sg_page(obj->pages->sgl, _iter, obj->pages->nents, 0) + for_each_sg_page(obj->pages->sgl, _iter, +obj->pages->nents, 0) pages[n++] = sg_page_iter_page(_iter); obj->vmapping = vmap(pages, n, 0, PAGE_KERNEL); Two problems I can spot are: 1. Callers of pin_vmap now don't know which kind of address they are getting. Maybe call it pin_kvmap or something? Just mention in kerneldoc could be enough. I think just mention, and we can rename this to i915_gem_object_pin_map(). Hmm. I liked the pin in the name since it ties to to pin_pages (later I plan to change that to get_pages and get_vmap/get_map as the pin becomes implicit). 2. Shrinker will try to kick out kmapped objects because they have obj->vmapping set. Not caring that much since the vmap_purge is very heavy weight, but we can apply is_vmalloc_addr() to the shrinker. Ok, happy to call this obj->mapping and i915_gem_object_pin_map() ? Sounds good. (Including the is_vmalloc_addr() smartening in the shrinker.) Regards, Tvrtko ___ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx
Re: [Intel-gfx] [PATCH 6/6] drm/i915: Avoid allocating a vmap arena for a single page
On Wed, Apr 06, 2016 at 10:49:36AM +0100, Tvrtko Ursulin wrote: > >diff --git a/drivers/gpu/drm/i915/i915_gem.c > >b/drivers/gpu/drm/i915/i915_gem.c > >index 985f067c1f0e..dc8e1b76c896 100644 > >--- a/drivers/gpu/drm/i915/i915_gem.c > >+++ b/drivers/gpu/drm/i915/i915_gem.c > >@@ -2233,7 +2233,10 @@ i915_gem_object_put_pages(struct drm_i915_gem_object > >*obj) > > list_del(>global_list); > > > > if (obj->vmapping) { > >-vunmap(obj->vmapping); > >+if (obj->base.size == PAGE_SIZE) > >+kunmap(kmap_to_page(obj->vmapping)); > >+else > >+vunmap(obj->vmapping); > > Can't think of a reason why it would be better but there is also > is_vmalloc_addr(addr) as used by kvfree. For consistency with the shrinker (see below). > > obj->vmapping = NULL; > > } > > > >@@ -2416,15 +2419,22 @@ void *i915_gem_object_pin_vmap(struct > >drm_i915_gem_object *obj) > > i915_gem_object_pin_pages(obj); > > > > if (obj->vmapping == NULL) { > >-struct sg_page_iter sg_iter; > > struct page **pages; > >-int n; > > > >-n = obj->base.size >> PAGE_SHIFT; > >-pages = drm_malloc_gfp(n, sizeof(*pages), GFP_TEMPORARY); > >+pages = NULL; > >+if (obj->base.size == PAGE_SIZE) > >+obj->vmapping = kmap(sg_page(obj->pages->sgl)); > >+else > >+pages = drm_malloc_gfp(obj->base.size >> PAGE_SHIFT, > >+ sizeof(*pages), > >+ GFP_TEMPORARY); > > if (pages != NULL) { > >+struct sg_page_iter sg_iter; > >+int n; > >+ > > n = 0; > >-for_each_sg_page(obj->pages->sgl, _iter, > >obj->pages->nents, 0) > >+for_each_sg_page(obj->pages->sgl, _iter, > >+ obj->pages->nents, 0) > > pages[n++] = sg_page_iter_page(_iter); > > > > obj->vmapping = vmap(pages, n, 0, PAGE_KERNEL); > > > > Two problems I can spot are: > > 1. Callers of pin_vmap now don't know which kind of address they are > getting. Maybe call it pin_kvmap or something? Just mention in > kerneldoc could be enough. I think just mention, and we can rename this to i915_gem_object_pin_map(). Hmm. I liked the pin in the name since it ties to to pin_pages (later I plan to change that to get_pages and get_vmap/get_map as the pin becomes implicit). > 2. Shrinker will try to kick out kmapped objects because they have > obj->vmapping set. Not caring that much since the vmap_purge is very heavy weight, but we can apply is_vmalloc_addr() to the shrinker. Ok, happy to call this obj->mapping and i915_gem_object_pin_map() ? -Chris -- Chris Wilson, Intel Open Source Technology Centre ___ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx
Re: [Intel-gfx] [PATCH 6/6] drm/i915: Avoid allocating a vmap arena for a single page
On 05/04/16 13:57, Chris Wilson wrote: If we want a contiguous mapping of a single page sized object, we can forgo using vmap() and just use a regular kmap(). Note that this is only suitable if the desired pgprot_t is comptabitible. You noticed the spelling already. :) Signed-off-by: Chris Wilson--- drivers/gpu/drm/i915/i915_gem.c | 22 -- 1 file changed, 16 insertions(+), 6 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 985f067c1f0e..dc8e1b76c896 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -2233,7 +2233,10 @@ i915_gem_object_put_pages(struct drm_i915_gem_object *obj) list_del(>global_list); if (obj->vmapping) { - vunmap(obj->vmapping); + if (obj->base.size == PAGE_SIZE) + kunmap(kmap_to_page(obj->vmapping)); + else + vunmap(obj->vmapping); Can't think of a reason why it would be better but there is also is_vmalloc_addr(addr) as used by kvfree. obj->vmapping = NULL; } @@ -2416,15 +2419,22 @@ void *i915_gem_object_pin_vmap(struct drm_i915_gem_object *obj) i915_gem_object_pin_pages(obj); if (obj->vmapping == NULL) { - struct sg_page_iter sg_iter; struct page **pages; - int n; - n = obj->base.size >> PAGE_SHIFT; - pages = drm_malloc_gfp(n, sizeof(*pages), GFP_TEMPORARY); + pages = NULL; + if (obj->base.size == PAGE_SIZE) + obj->vmapping = kmap(sg_page(obj->pages->sgl)); + else + pages = drm_malloc_gfp(obj->base.size >> PAGE_SHIFT, + sizeof(*pages), + GFP_TEMPORARY); if (pages != NULL) { + struct sg_page_iter sg_iter; + int n; + n = 0; - for_each_sg_page(obj->pages->sgl, _iter, obj->pages->nents, 0) + for_each_sg_page(obj->pages->sgl, _iter, +obj->pages->nents, 0) pages[n++] = sg_page_iter_page(_iter); obj->vmapping = vmap(pages, n, 0, PAGE_KERNEL); Two problems I can spot are: 1. Callers of pin_vmap now don't know which kind of address they are getting. Maybe call it pin_kvmap or something? Just mention in kerneldoc could be enough. 2. Shrinker will try to kick out kmapped objects because they have obj->vmapping set. Regards, Tvrtko ___ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx
Re: [Intel-gfx] [PATCH 6/6] drm/i915: Avoid allocating a vmap arena for a single page
I use :autocmd FileType gitcommit setlocal spell ___ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx
Re: [Intel-gfx] [PATCH 6/6] drm/i915: Avoid allocating a vmap arena for a single page
On Tue, Apr 05, 2016 at 01:57:37PM +0100, Chris Wilson wrote: > If we want a contiguous mapping of a single page sized object, we can > forgo using vmap() and just use a regular kmap(). Note that this is only > suitable if the desired pgprot_t is comptabitible. One day, I will enable :set spell. Does anyone know if there is a .vim rule to detect git? Or something to stuff in git config core.editor ? -Chris -- Chris Wilson, Intel Open Source Technology Centre ___ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx
[Intel-gfx] [PATCH 6/6] drm/i915: Avoid allocating a vmap arena for a single page
If we want a contiguous mapping of a single page sized object, we can forgo using vmap() and just use a regular kmap(). Note that this is only suitable if the desired pgprot_t is comptabitible. Signed-off-by: Chris Wilson--- drivers/gpu/drm/i915/i915_gem.c | 22 -- 1 file changed, 16 insertions(+), 6 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 985f067c1f0e..dc8e1b76c896 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -2233,7 +2233,10 @@ i915_gem_object_put_pages(struct drm_i915_gem_object *obj) list_del(>global_list); if (obj->vmapping) { - vunmap(obj->vmapping); + if (obj->base.size == PAGE_SIZE) + kunmap(kmap_to_page(obj->vmapping)); + else + vunmap(obj->vmapping); obj->vmapping = NULL; } @@ -2416,15 +2419,22 @@ void *i915_gem_object_pin_vmap(struct drm_i915_gem_object *obj) i915_gem_object_pin_pages(obj); if (obj->vmapping == NULL) { - struct sg_page_iter sg_iter; struct page **pages; - int n; - n = obj->base.size >> PAGE_SHIFT; - pages = drm_malloc_gfp(n, sizeof(*pages), GFP_TEMPORARY); + pages = NULL; + if (obj->base.size == PAGE_SIZE) + obj->vmapping = kmap(sg_page(obj->pages->sgl)); + else + pages = drm_malloc_gfp(obj->base.size >> PAGE_SHIFT, + sizeof(*pages), + GFP_TEMPORARY); if (pages != NULL) { + struct sg_page_iter sg_iter; + int n; + n = 0; - for_each_sg_page(obj->pages->sgl, _iter, obj->pages->nents, 0) + for_each_sg_page(obj->pages->sgl, _iter, +obj->pages->nents, 0) pages[n++] = sg_page_iter_page(_iter); obj->vmapping = vmap(pages, n, 0, PAGE_KERNEL); -- 2.8.0.rc3 ___ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx