* [PATCH 0/4] Compact userptr object backing store allocation
@ 2016-11-11 8:50 Tvrtko Ursulin
2016-11-11 8:50 ` [PATCH 1/4] lib/scatterlist: Fix offset type in sg_alloc_table_from_pages Tvrtko Ursulin
` (4 more replies)
0 siblings, 5 replies; 21+ messages in thread
From: Tvrtko Ursulin @ 2016-11-11 8:50 UTC (permalink / raw)
To: Intel-gfx; +Cc: linux-kernel, Tvrtko Ursulin
From: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Userptr backing store with SWIOTBL active is currently allocated in the same
inefficient manner, with one sg entry per object page, as what the commit
871dfbd67d4e ("drm/i915: Allow compaction upto SWIOTLB max segment size") fixed
for regular GEM objects.
We can fix that by adding new a __sg_alloc_table_from_pages core function which
allows us to control the maximum desired coalesced segment size.
Other than that the series starts with two simple fixes to
sg_alloc_table_from_pages which deal with incorrect data type usage and a
theoretical overflow condition. Fixing the latter enables easy addition of the
above mentioned __sg_alloc_table_from_pages.
Tvrtko Ursulin (4):
lib/scatterlist: Fix offset type in sg_alloc_table_from_pages
lib/scatterlist: Avoid potential scatterlist entry overflow
lib/scatterlist: Introduce and export __sg_alloc_table_from_pages
drm/i915: Use __sg_alloc_table_from_pages for userptr allocations
drivers/gpu/drm/i915/i915_drv.h | 9 +++
drivers/gpu/drm/i915/i915_gem.c | 15 +----
drivers/gpu/drm/i915/i915_gem_userptr.c | 28 ++-------
drivers/media/v4l2-core/videobuf2-dma-contig.c | 4 +-
drivers/rapidio/devices/rio_mport_cdev.c | 4 +-
include/linux/scatterlist.h | 11 ++--
lib/scatterlist.c | 78 ++++++++++++++++++++------
7 files changed, 87 insertions(+), 62 deletions(-)
--
2.7.4
^ permalink raw reply [flat|nested] 21+ messages in thread
* [PATCH 1/4] lib/scatterlist: Fix offset type in sg_alloc_table_from_pages
2016-11-11 8:50 [PATCH 0/4] Compact userptr object backing store allocation Tvrtko Ursulin
@ 2016-11-11 8:50 ` Tvrtko Ursulin
2016-11-14 9:55 ` [Intel-gfx] " Chris Wilson
2016-11-11 8:50 ` [PATCH 2/4] lib/scatterlist: Avoid potential scatterlist entry overflow Tvrtko Ursulin
` (3 subsequent siblings)
4 siblings, 1 reply; 21+ messages in thread
From: Tvrtko Ursulin @ 2016-11-11 8:50 UTC (permalink / raw)
To: Intel-gfx
Cc: linux-kernel, Tvrtko Ursulin, Masahiro Yamada, Pawel Osciak,
Marek Szyprowski, Kyungmin Park, Tomasz Stanislawski,
Matt Porter, Alexandre Bounine, linux-media
From: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Scatterlist entries have an unsigned int for the offset so
correct the sg_alloc_table_from_pages function accordingly.
Since these are offsets withing a page, unsigned int is
wide enough.
Also converts callers which were using unsigned long locally
with the lower_32_bits annotation to make it explicitly
clear what is happening.
v2: Use offset_in_page. (Chris Wilson)
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Pawel Osciak <pawel@osciak.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Tomasz Stanislawski <t.stanislaws@samsung.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Alexandre Bounine <alexandre.bounine@idt.com>
Cc: linux-media@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com> (v1)
---
drivers/media/v4l2-core/videobuf2-dma-contig.c | 4 ++--
drivers/rapidio/devices/rio_mport_cdev.c | 4 ++--
include/linux/scatterlist.h | 2 +-
lib/scatterlist.c | 2 +-
4 files changed, 6 insertions(+), 6 deletions(-)
diff --git a/drivers/media/v4l2-core/videobuf2-dma-contig.c b/drivers/media/v4l2-core/videobuf2-dma-contig.c
index fb6a177be461..51e8765bc3c6 100644
--- a/drivers/media/v4l2-core/videobuf2-dma-contig.c
+++ b/drivers/media/v4l2-core/videobuf2-dma-contig.c
@@ -478,7 +478,7 @@ static void *vb2_dc_get_userptr(struct device *dev, unsigned long vaddr,
{
struct vb2_dc_buf *buf;
struct frame_vector *vec;
- unsigned long offset;
+ unsigned int offset;
int n_pages, i;
int ret = 0;
struct sg_table *sgt;
@@ -506,7 +506,7 @@ static void *vb2_dc_get_userptr(struct device *dev, unsigned long vaddr,
buf->dev = dev;
buf->dma_dir = dma_dir;
- offset = vaddr & ~PAGE_MASK;
+ offset = lower_32_bits(offset_in_page(vaddr));
vec = vb2_create_framevec(vaddr, size, dma_dir == DMA_FROM_DEVICE);
if (IS_ERR(vec)) {
ret = PTR_ERR(vec);
diff --git a/drivers/rapidio/devices/rio_mport_cdev.c b/drivers/rapidio/devices/rio_mport_cdev.c
index 9013a585507e..0fae29ff47ba 100644
--- a/drivers/rapidio/devices/rio_mport_cdev.c
+++ b/drivers/rapidio/devices/rio_mport_cdev.c
@@ -876,10 +876,10 @@ rio_dma_transfer(struct file *filp, u32 transfer_mode,
* offset within the internal buffer specified by handle parameter.
*/
if (xfer->loc_addr) {
- unsigned long offset;
+ unsigned int offset;
long pinned;
- offset = (unsigned long)(uintptr_t)xfer->loc_addr & ~PAGE_MASK;
+ offset = lower_32_bits(offset_in_page(xfer->loc_addr));
nr_pages = PAGE_ALIGN(xfer->length + offset) >> PAGE_SHIFT;
page_list = kmalloc_array(nr_pages,
diff --git a/include/linux/scatterlist.h b/include/linux/scatterlist.h
index cb3c8fe6acd7..c981bee1a3ae 100644
--- a/include/linux/scatterlist.h
+++ b/include/linux/scatterlist.h
@@ -263,7 +263,7 @@ int __sg_alloc_table(struct sg_table *, unsigned int, unsigned int,
int sg_alloc_table(struct sg_table *, unsigned int, gfp_t);
int sg_alloc_table_from_pages(struct sg_table *sgt,
struct page **pages, unsigned int n_pages,
- unsigned long offset, unsigned long size,
+ unsigned int offset, unsigned long size,
gfp_t gfp_mask);
size_t sg_copy_buffer(struct scatterlist *sgl, unsigned int nents, void *buf,
diff --git a/lib/scatterlist.c b/lib/scatterlist.c
index 004fc70fc56a..e05e7fc98892 100644
--- a/lib/scatterlist.c
+++ b/lib/scatterlist.c
@@ -391,7 +391,7 @@ EXPORT_SYMBOL(sg_alloc_table);
*/
int sg_alloc_table_from_pages(struct sg_table *sgt,
struct page **pages, unsigned int n_pages,
- unsigned long offset, unsigned long size,
+ unsigned int offset, unsigned long size,
gfp_t gfp_mask)
{
unsigned int chunks;
--
2.7.4
^ permalink raw reply related [flat|nested] 21+ messages in thread
* [PATCH 2/4] lib/scatterlist: Avoid potential scatterlist entry overflow
2016-11-11 8:50 [PATCH 0/4] Compact userptr object backing store allocation Tvrtko Ursulin
2016-11-11 8:50 ` [PATCH 1/4] lib/scatterlist: Fix offset type in sg_alloc_table_from_pages Tvrtko Ursulin
@ 2016-11-11 8:50 ` Tvrtko Ursulin
2016-11-11 10:19 ` [Intel-gfx] " Chris Wilson
2016-11-11 8:50 ` [PATCH 3/4] lib/scatterlist: Introduce and export __sg_alloc_table_from_pages Tvrtko Ursulin
` (2 subsequent siblings)
4 siblings, 1 reply; 21+ messages in thread
From: Tvrtko Ursulin @ 2016-11-11 8:50 UTC (permalink / raw)
To: Intel-gfx; +Cc: linux-kernel, Tvrtko Ursulin, Masahiro Yamada
From: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Since the scatterlist length field is an unsigned int, make
sure that sg_alloc_table_from_pages does not overflow it while
coallescing pages to a single entry.
v2: Drop reference to future use. Use UINT_MAX.
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: linux-kernel@vger.kernel.org
---
lib/scatterlist.c | 25 +++++++++++++++++++------
1 file changed, 19 insertions(+), 6 deletions(-)
diff --git a/lib/scatterlist.c b/lib/scatterlist.c
index e05e7fc98892..de15f369b317 100644
--- a/lib/scatterlist.c
+++ b/lib/scatterlist.c
@@ -394,7 +394,8 @@ int sg_alloc_table_from_pages(struct sg_table *sgt,
unsigned int offset, unsigned long size,
gfp_t gfp_mask)
{
- unsigned int chunks;
+ const unsigned int max_segment = UINT_MAX;
+ unsigned int seg_len, chunks;
unsigned int i;
unsigned int cur_page;
int ret;
@@ -402,9 +403,16 @@ int sg_alloc_table_from_pages(struct sg_table *sgt,
/* compute number of contiguous chunks */
chunks = 1;
- for (i = 1; i < n_pages; ++i)
- if (page_to_pfn(pages[i]) != page_to_pfn(pages[i - 1]) + 1)
+ seg_len = PAGE_SIZE;
+ for (i = 1; i < n_pages; ++i) {
+ if (seg_len >= max_segment ||
+ page_to_pfn(pages[i]) != page_to_pfn(pages[i - 1]) + 1) {
++chunks;
+ seg_len = PAGE_SIZE;
+ } else {
+ seg_len += PAGE_SIZE;
+ }
+ }
ret = sg_alloc_table(sgt, chunks, gfp_mask);
if (unlikely(ret))
@@ -413,17 +421,22 @@ int sg_alloc_table_from_pages(struct sg_table *sgt,
/* merging chunks and putting them into the scatterlist */
cur_page = 0;
for_each_sg(sgt->sgl, s, sgt->orig_nents, i) {
- unsigned long chunk_size;
+ unsigned int chunk_size;
unsigned int j;
/* look for the end of the current chunk */
+ seg_len = PAGE_SIZE;
for (j = cur_page + 1; j < n_pages; ++j)
- if (page_to_pfn(pages[j]) !=
+ if (seg_len >= max_segment ||
+ page_to_pfn(pages[j]) !=
page_to_pfn(pages[j - 1]) + 1)
break;
+ else
+ seg_len += PAGE_SIZE;
chunk_size = ((j - cur_page) << PAGE_SHIFT) - offset;
- sg_set_page(s, pages[cur_page], min(size, chunk_size), offset);
+ sg_set_page(s, pages[cur_page],
+ min_t(unsigned long, size, chunk_size), offset);
size -= chunk_size;
offset = 0;
cur_page = j;
--
2.7.4
^ permalink raw reply related [flat|nested] 21+ messages in thread
* [PATCH 3/4] lib/scatterlist: Introduce and export __sg_alloc_table_from_pages
2016-11-11 8:50 [PATCH 0/4] Compact userptr object backing store allocation Tvrtko Ursulin
2016-11-11 8:50 ` [PATCH 1/4] lib/scatterlist: Fix offset type in sg_alloc_table_from_pages Tvrtko Ursulin
2016-11-11 8:50 ` [PATCH 2/4] lib/scatterlist: Avoid potential scatterlist entry overflow Tvrtko Ursulin
@ 2016-11-11 8:50 ` Tvrtko Ursulin
2016-11-11 10:24 ` [Intel-gfx] " Chris Wilson
2016-11-11 8:50 ` [PATCH 4/4] drm/i915: Use __sg_alloc_table_from_pages for userptr allocations Tvrtko Ursulin
2016-11-14 11:45 ` [Intel-gfx] [PATCH 0/4] Compact userptr object backing store allocation Tvrtko Ursulin
4 siblings, 1 reply; 21+ messages in thread
From: Tvrtko Ursulin @ 2016-11-11 8:50 UTC (permalink / raw)
To: Intel-gfx; +Cc: linux-kernel, Tvrtko Ursulin, Masahiro Yamada
From: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Drivers like i915 benefit from being able to control the maxium
size of the sg coallesced segment while building the scatter-
gather list.
Introduce and export the __sg_alloc_table_from_pages function
which will allow it that control.
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: linux-kernel@vger.kernel.org
---
include/linux/scatterlist.h | 11 +++++----
lib/scatterlist.c | 55 ++++++++++++++++++++++++++++++++++-----------
2 files changed, 49 insertions(+), 17 deletions(-)
diff --git a/include/linux/scatterlist.h b/include/linux/scatterlist.h
index c981bee1a3ae..29591dbb20fd 100644
--- a/include/linux/scatterlist.h
+++ b/include/linux/scatterlist.h
@@ -261,10 +261,13 @@ void sg_free_table(struct sg_table *);
int __sg_alloc_table(struct sg_table *, unsigned int, unsigned int,
struct scatterlist *, gfp_t, sg_alloc_fn *);
int sg_alloc_table(struct sg_table *, unsigned int, gfp_t);
-int sg_alloc_table_from_pages(struct sg_table *sgt,
- struct page **pages, unsigned int n_pages,
- unsigned int offset, unsigned long size,
- gfp_t gfp_mask);
+int __sg_alloc_table_from_pages(struct sg_table *sgt, struct page **pages,
+ unsigned int n_pages, unsigned int offset,
+ unsigned long size, gfp_t gfp_mask,
+ unsigned int max_segment);
+int sg_alloc_table_from_pages(struct sg_table *sgt, struct page **pages,
+ unsigned int n_pages, unsigned int offset,
+ unsigned long size, gfp_t gfp_mask);
size_t sg_copy_buffer(struct scatterlist *sgl, unsigned int nents, void *buf,
size_t buflen, off_t skip, bool to_buffer);
diff --git a/lib/scatterlist.c b/lib/scatterlist.c
index de15f369b317..c0521420f931 100644
--- a/lib/scatterlist.c
+++ b/lib/scatterlist.c
@@ -370,14 +370,15 @@ int sg_alloc_table(struct sg_table *table, unsigned int nents, gfp_t gfp_mask)
EXPORT_SYMBOL(sg_alloc_table);
/**
- * sg_alloc_table_from_pages - Allocate and initialize an sg table from
- * an array of pages
- * @sgt: The sg table header to use
- * @pages: Pointer to an array of page pointers
- * @n_pages: Number of pages in the pages array
- * @offset: Offset from start of the first page to the start of a buffer
- * @size: Number of valid bytes in the buffer (after offset)
- * @gfp_mask: GFP allocation mask
+ * __sg_alloc_table_from_pages - Allocate and initialize an sg table from
+ * an array of pages
+ * @sgt: The sg table header to use
+ * @pages: Pointer to an array of page pointers
+ * @n_pages: Number of pages in the pages array
+ * @offset: Offset from start of the first page to the start of a buffer
+ * @size: Number of valid bytes in the buffer (after offset)
+ * @gfp_mask: GFP allocation mask
+ * @max_segment: Maximum size of a single scatterlist node in bytes
*
* Description:
* Allocate and initialize an sg table from a list of pages. Contiguous
@@ -389,12 +390,11 @@ EXPORT_SYMBOL(sg_alloc_table);
* Returns:
* 0 on success, negative error on failure
*/
-int sg_alloc_table_from_pages(struct sg_table *sgt,
- struct page **pages, unsigned int n_pages,
- unsigned int offset, unsigned long size,
- gfp_t gfp_mask)
+int __sg_alloc_table_from_pages(struct sg_table *sgt, struct page **pages,
+ unsigned int n_pages, unsigned int offset,
+ unsigned long size, gfp_t gfp_mask,
+ unsigned int max_segment)
{
- const unsigned int max_segment = UINT_MAX;
unsigned int seg_len, chunks;
unsigned int i;
unsigned int cur_page;
@@ -444,6 +444,35 @@ int sg_alloc_table_from_pages(struct sg_table *sgt,
return 0;
}
+EXPORT_SYMBOL(__sg_alloc_table_from_pages);
+
+/**
+ * sg_alloc_table_from_pages - Allocate and initialize an sg table from
+ * an array of pages
+ * @sgt: The sg table header to use
+ * @pages: Pointer to an array of page pointers
+ * @n_pages: Number of pages in the pages array
+ * @offset: Offset from start of the first page to the start of a buffer
+ * @size: Number of valid bytes in the buffer (after offset)
+ * @gfp_mask: GFP allocation mask
+ *
+ * Description:
+ * Allocate and initialize an sg table from a list of pages. Contiguous
+ * ranges of the pages are squashed into a single scatterlist node. A user
+ * may provide an offset at a start and a size of valid data in a buffer
+ * specified by the page array. The returned sg table is released by
+ * sg_free_table.
+ *
+ * Returns:
+ * 0 on success, negative error on failure
+ */
+int sg_alloc_table_from_pages(struct sg_table *sgt, struct page **pages,
+ unsigned int n_pages, unsigned int offset,
+ unsigned long size, gfp_t gfp_mask)
+{
+ return __sg_alloc_table_from_pages(sgt, pages, n_pages, offset,
+ size, gfp_mask, UINT_MAX);
+}
EXPORT_SYMBOL(sg_alloc_table_from_pages);
void __sg_page_iter_start(struct sg_page_iter *piter,
--
2.7.4
^ permalink raw reply related [flat|nested] 21+ messages in thread
* [PATCH 4/4] drm/i915: Use __sg_alloc_table_from_pages for userptr allocations
2016-11-11 8:50 [PATCH 0/4] Compact userptr object backing store allocation Tvrtko Ursulin
` (2 preceding siblings ...)
2016-11-11 8:50 ` [PATCH 3/4] lib/scatterlist: Introduce and export __sg_alloc_table_from_pages Tvrtko Ursulin
@ 2016-11-11 8:50 ` Tvrtko Ursulin
2016-11-11 8:59 ` [PATCH v3 " Tvrtko Ursulin
2016-11-11 10:23 ` [PATCH " Chris Wilson
2016-11-14 11:45 ` [Intel-gfx] [PATCH 0/4] Compact userptr object backing store allocation Tvrtko Ursulin
4 siblings, 2 replies; 21+ messages in thread
From: Tvrtko Ursulin @ 2016-11-11 8:50 UTC (permalink / raw)
To: Intel-gfx; +Cc: linux-kernel, Tvrtko Ursulin, Chris Wilson
From: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
With the addition of __sg_alloc_table_from_pages we can control
the maximum coallescing size and eliminate a separate path for
allocating backing store here.
Similar to 871dfbd67d4e ("drm/i915: Allow compaction upto
SWIOTLB max segment size") this enables more compact sg lists to
be created and so has a beneficial effect on workloads with many
and/or large objects of this class.
v2:
* Rename helper to i915_sg_segment_size and fix swiotlb override.
* Commit message update.
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
---
drivers/gpu/drm/i915/i915_drv.h | 9 +++++++++
drivers/gpu/drm/i915/i915_gem.c | 15 +--------------
drivers/gpu/drm/i915/i915_gem_userptr.c | 28 ++++++----------------------
3 files changed, 16 insertions(+), 36 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 30777dee3f9c..319f8def0f86 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -4175,4 +4175,13 @@ int remap_io_mapping(struct vm_area_struct *vma,
__T; \
})
+static inline unsigned int i915_sg_segment_size(void)
+{
+#if IS_ENABLED(CONFIG_SWIOTLB)
+ return swiotlb_nr_tbl() << IO_TLB_SHIFT;
+#else
+ return UINT_MAX;
+#endif
+}
+
#endif
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 1c20edba7f2a..cb4c188a395c 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2223,15 +2223,6 @@ void __i915_gem_object_put_pages(struct drm_i915_gem_object *obj,
mutex_unlock(&obj->mm.lock);
}
-static unsigned int swiotlb_max_size(void)
-{
-#if IS_ENABLED(CONFIG_SWIOTLB)
- return rounddown(swiotlb_nr_tbl() << IO_TLB_SHIFT, PAGE_SIZE);
-#else
- return 0;
-#endif
-}
-
static void i915_sg_trim(struct sg_table *orig_st)
{
struct sg_table new_st;
@@ -2267,7 +2258,7 @@ i915_gem_object_get_pages_gtt(struct drm_i915_gem_object *obj)
struct sgt_iter sgt_iter;
struct page *page;
unsigned long last_pfn = 0; /* suppress gcc warning */
- unsigned int max_segment;
+ unsigned int max_segment = rounddown(i915_sg_segment_size(), PAGE_SIZE);
int ret;
gfp_t gfp;
@@ -2278,10 +2269,6 @@ i915_gem_object_get_pages_gtt(struct drm_i915_gem_object *obj)
GEM_BUG_ON(obj->base.read_domains & I915_GEM_GPU_DOMAINS);
GEM_BUG_ON(obj->base.write_domain & I915_GEM_GPU_DOMAINS);
- max_segment = swiotlb_max_size();
- if (!max_segment)
- max_segment = rounddown(UINT_MAX, PAGE_SIZE);
-
st = kmalloc(sizeof(*st), GFP_KERNEL);
if (st == NULL)
return ERR_PTR(-ENOMEM);
diff --git a/drivers/gpu/drm/i915/i915_gem_userptr.c b/drivers/gpu/drm/i915/i915_gem_userptr.c
index 64261639f547..b4461f1832a6 100644
--- a/drivers/gpu/drm/i915/i915_gem_userptr.c
+++ b/drivers/gpu/drm/i915/i915_gem_userptr.c
@@ -390,36 +390,20 @@ struct get_pages_work {
struct task_struct *task;
};
-#if IS_ENABLED(CONFIG_SWIOTLB)
-#define swiotlb_active() swiotlb_nr_tbl()
-#else
-#define swiotlb_active() 0
-#endif
-
static int
st_set_pages(struct sg_table **st, struct page **pvec, int num_pages)
{
- struct scatterlist *sg;
- int ret, n;
+ int ret;
*st = kmalloc(sizeof(**st), GFP_KERNEL);
if (*st == NULL)
return -ENOMEM;
- if (swiotlb_active()) {
- ret = sg_alloc_table(*st, num_pages, GFP_KERNEL);
- if (ret)
- goto err;
-
- for_each_sg((*st)->sgl, sg, num_pages, n)
- sg_set_page(sg, pvec[n], PAGE_SIZE, 0);
- } else {
- ret = sg_alloc_table_from_pages(*st, pvec, num_pages,
- 0, num_pages << PAGE_SHIFT,
- GFP_KERNEL);
- if (ret)
- goto err;
- }
+ ret = __sg_alloc_table_from_pages(*st, pvec, num_pages, 0,
+ num_pages << PAGE_SHIFT,
+ GFP_KERNEL, i915_sg_segment_size());
+ if (ret)
+ goto err;
return 0;
--
2.7.4
^ permalink raw reply related [flat|nested] 21+ messages in thread
* [PATCH v3 4/4] drm/i915: Use __sg_alloc_table_from_pages for userptr allocations
2016-11-11 8:50 ` [PATCH 4/4] drm/i915: Use __sg_alloc_table_from_pages for userptr allocations Tvrtko Ursulin
@ 2016-11-11 8:59 ` Tvrtko Ursulin
2016-11-11 10:23 ` [PATCH " Chris Wilson
1 sibling, 0 replies; 21+ messages in thread
From: Tvrtko Ursulin @ 2016-11-11 8:59 UTC (permalink / raw)
To: Intel-gfx; +Cc: linux-kernel, Tvrtko Ursulin, Chris Wilson
From: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
With the addition of __sg_alloc_table_from_pages we can control
the maximum coallescing size and eliminate a separate path for
allocating backing store here.
Similar to 871dfbd67d4e ("drm/i915: Allow compaction upto
SWIOTLB max segment size") this enables more compact sg lists to
be created and so has a beneficial effect on workloads with many
and/or large objects of this class.
v2:
* Rename helper to i915_sg_segment_size and fix swiotlb override.
* Commit message update.
v3:
* Actually include the swiotlb override fix.
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
---
drivers/gpu/drm/i915/i915_drv.h | 11 +++++++++++
drivers/gpu/drm/i915/i915_gem.c | 15 +--------------
drivers/gpu/drm/i915/i915_gem_userptr.c | 28 ++++++----------------------
3 files changed, 18 insertions(+), 36 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 30777dee3f9c..38a555c9c44b 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -4175,4 +4175,15 @@ int remap_io_mapping(struct vm_area_struct *vma,
__T; \
})
+static inline unsigned int i915_sg_segment_size(void)
+{
+#if IS_ENABLED(CONFIG_SWIOTLB)
+ unsigned int nr_tbl = swiotlb_nr_tbl();
+
+ return nr_tbl > 0 ? nr_tbl << IO_TLB_SHIFT : UINT_MAX;
+#else
+ return UINT_MAX;
+#endif
+}
+
#endif
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 1c20edba7f2a..cb4c188a395c 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2223,15 +2223,6 @@ void __i915_gem_object_put_pages(struct drm_i915_gem_object *obj,
mutex_unlock(&obj->mm.lock);
}
-static unsigned int swiotlb_max_size(void)
-{
-#if IS_ENABLED(CONFIG_SWIOTLB)
- return rounddown(swiotlb_nr_tbl() << IO_TLB_SHIFT, PAGE_SIZE);
-#else
- return 0;
-#endif
-}
-
static void i915_sg_trim(struct sg_table *orig_st)
{
struct sg_table new_st;
@@ -2267,7 +2258,7 @@ i915_gem_object_get_pages_gtt(struct drm_i915_gem_object *obj)
struct sgt_iter sgt_iter;
struct page *page;
unsigned long last_pfn = 0; /* suppress gcc warning */
- unsigned int max_segment;
+ unsigned int max_segment = rounddown(i915_sg_segment_size(), PAGE_SIZE);
int ret;
gfp_t gfp;
@@ -2278,10 +2269,6 @@ i915_gem_object_get_pages_gtt(struct drm_i915_gem_object *obj)
GEM_BUG_ON(obj->base.read_domains & I915_GEM_GPU_DOMAINS);
GEM_BUG_ON(obj->base.write_domain & I915_GEM_GPU_DOMAINS);
- max_segment = swiotlb_max_size();
- if (!max_segment)
- max_segment = rounddown(UINT_MAX, PAGE_SIZE);
-
st = kmalloc(sizeof(*st), GFP_KERNEL);
if (st == NULL)
return ERR_PTR(-ENOMEM);
diff --git a/drivers/gpu/drm/i915/i915_gem_userptr.c b/drivers/gpu/drm/i915/i915_gem_userptr.c
index 64261639f547..b4461f1832a6 100644
--- a/drivers/gpu/drm/i915/i915_gem_userptr.c
+++ b/drivers/gpu/drm/i915/i915_gem_userptr.c
@@ -390,36 +390,20 @@ struct get_pages_work {
struct task_struct *task;
};
-#if IS_ENABLED(CONFIG_SWIOTLB)
-#define swiotlb_active() swiotlb_nr_tbl()
-#else
-#define swiotlb_active() 0
-#endif
-
static int
st_set_pages(struct sg_table **st, struct page **pvec, int num_pages)
{
- struct scatterlist *sg;
- int ret, n;
+ int ret;
*st = kmalloc(sizeof(**st), GFP_KERNEL);
if (*st == NULL)
return -ENOMEM;
- if (swiotlb_active()) {
- ret = sg_alloc_table(*st, num_pages, GFP_KERNEL);
- if (ret)
- goto err;
-
- for_each_sg((*st)->sgl, sg, num_pages, n)
- sg_set_page(sg, pvec[n], PAGE_SIZE, 0);
- } else {
- ret = sg_alloc_table_from_pages(*st, pvec, num_pages,
- 0, num_pages << PAGE_SHIFT,
- GFP_KERNEL);
- if (ret)
- goto err;
- }
+ ret = __sg_alloc_table_from_pages(*st, pvec, num_pages, 0,
+ num_pages << PAGE_SHIFT,
+ GFP_KERNEL, i915_sg_segment_size());
+ if (ret)
+ goto err;
return 0;
--
2.7.4
^ permalink raw reply related [flat|nested] 21+ messages in thread
* Re: [Intel-gfx] [PATCH 2/4] lib/scatterlist: Avoid potential scatterlist entry overflow
2016-11-11 8:50 ` [PATCH 2/4] lib/scatterlist: Avoid potential scatterlist entry overflow Tvrtko Ursulin
@ 2016-11-11 10:19 ` Chris Wilson
0 siblings, 0 replies; 21+ messages in thread
From: Chris Wilson @ 2016-11-11 10:19 UTC (permalink / raw)
To: Tvrtko Ursulin; +Cc: Intel-gfx, Masahiro Yamada, linux-kernel
On Fri, Nov 11, 2016 at 08:50:18AM +0000, Tvrtko Ursulin wrote:
> From: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
>
> Since the scatterlist length field is an unsigned int, make
> sure that sg_alloc_table_from_pages does not overflow it while
> coallescing pages to a single entry.
>
> v2: Drop reference to future use. Use UINT_MAX.
>
> Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
> Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
> Cc: linux-kernel@vger.kernel.org
> ---
> lib/scatterlist.c | 25 +++++++++++++++++++------
> 1 file changed, 19 insertions(+), 6 deletions(-)
>
> diff --git a/lib/scatterlist.c b/lib/scatterlist.c
> index e05e7fc98892..de15f369b317 100644
> --- a/lib/scatterlist.c
> +++ b/lib/scatterlist.c
> @@ -394,7 +394,8 @@ int sg_alloc_table_from_pages(struct sg_table *sgt,
> unsigned int offset, unsigned long size,
> gfp_t gfp_mask)
> {
> - unsigned int chunks;
> + const unsigned int max_segment = UINT_MAX;
> + unsigned int seg_len, chunks;
> unsigned int i;
> unsigned int cur_page;
> int ret;
> @@ -402,9 +403,16 @@ int sg_alloc_table_from_pages(struct sg_table *sgt,
>
> /* compute number of contiguous chunks */
> chunks = 1;
> - for (i = 1; i < n_pages; ++i)
> - if (page_to_pfn(pages[i]) != page_to_pfn(pages[i - 1]) + 1)
> + seg_len = PAGE_SIZE;
> + for (i = 1; i < n_pages; ++i) {
> + if (seg_len >= max_segment ||
> + page_to_pfn(pages[i]) != page_to_pfn(pages[i - 1]) + 1) {
> ++chunks;
> + seg_len = PAGE_SIZE;
> + } else {
> + seg_len += PAGE_SIZE;
> + }
> + }
>
> ret = sg_alloc_table(sgt, chunks, gfp_mask);
> if (unlikely(ret))
> @@ -413,17 +421,22 @@ int sg_alloc_table_from_pages(struct sg_table *sgt,
> /* merging chunks and putting them into the scatterlist */
> cur_page = 0;
> for_each_sg(sgt->sgl, s, sgt->orig_nents, i) {
> - unsigned long chunk_size;
> + unsigned int chunk_size;
> unsigned int j;
>
> /* look for the end of the current chunk */
> + seg_len = PAGE_SIZE;
> for (j = cur_page + 1; j < n_pages; ++j)
> - if (page_to_pfn(pages[j]) !=
> + if (seg_len >= max_segment ||
> + page_to_pfn(pages[j]) !=
> page_to_pfn(pages[j - 1]) + 1)
> break;
> + else
> + seg_len += PAGE_SIZE;
>
> chunk_size = ((j - cur_page) << PAGE_SHIFT) - offset;
chunk_size = seg_len - offset;
?
> - sg_set_page(s, pages[cur_page], min(size, chunk_size), offset);
> + sg_set_page(s, pages[cur_page],
> + min_t(unsigned long, size, chunk_size), offset);
> size -= chunk_size;
> offset = 0;
> cur_page = j;
Could BUG_ON(size); afterwards and BUG_ON(!size) inside? Although that
requires the caller didn't make a mistake in n_pages vs offset+size.
Minor comments,
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
-Chris
--
Chris Wilson, Intel Open Source Technology Centre
^ permalink raw reply [flat|nested] 21+ messages in thread
* Re: [PATCH 4/4] drm/i915: Use __sg_alloc_table_from_pages for userptr allocations
2016-11-11 8:50 ` [PATCH 4/4] drm/i915: Use __sg_alloc_table_from_pages for userptr allocations Tvrtko Ursulin
2016-11-11 8:59 ` [PATCH v3 " Tvrtko Ursulin
@ 2016-11-11 10:23 ` Chris Wilson
2016-11-11 12:36 ` [PATCH v4 " Tvrtko Ursulin
1 sibling, 1 reply; 21+ messages in thread
From: Chris Wilson @ 2016-11-11 10:23 UTC (permalink / raw)
To: Tvrtko Ursulin; +Cc: Intel-gfx, linux-kernel, Tvrtko Ursulin
On Fri, Nov 11, 2016 at 08:50:20AM +0000, Tvrtko Ursulin wrote:
> From: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
>
> With the addition of __sg_alloc_table_from_pages we can control
> the maximum coallescing size and eliminate a separate path for
> allocating backing store here.
>
> Similar to 871dfbd67d4e ("drm/i915: Allow compaction upto
> SWIOTLB max segment size") this enables more compact sg lists to
> be created and so has a beneficial effect on workloads with many
> and/or large objects of this class.
>
> v2:
> * Rename helper to i915_sg_segment_size and fix swiotlb override.
> * Commit message update.
>
> Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
> Cc: Chris Wilson <chris@chris-wilson.co.uk>
> ---
> drivers/gpu/drm/i915/i915_drv.h | 9 +++++++++
> drivers/gpu/drm/i915/i915_gem.c | 15 +--------------
> drivers/gpu/drm/i915/i915_gem_userptr.c | 28 ++++++----------------------
> 3 files changed, 16 insertions(+), 36 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 30777dee3f9c..319f8def0f86 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -4175,4 +4175,13 @@ int remap_io_mapping(struct vm_area_struct *vma,
> __T; \
> })
>
> +static inline unsigned int i915_sg_segment_size(void)
> +{
> +#if IS_ENABLED(CONFIG_SWIOTLB)
> + return swiotlb_nr_tbl() << IO_TLB_SHIFT;
> +#else
> + return UINT_MAX;
> +#endif
> +}
> +
> #endif
> diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
> index 1c20edba7f2a..cb4c188a395c 100644
> --- a/drivers/gpu/drm/i915/i915_gem.c
> +++ b/drivers/gpu/drm/i915/i915_gem.c
> @@ -2223,15 +2223,6 @@ void __i915_gem_object_put_pages(struct drm_i915_gem_object *obj,
> mutex_unlock(&obj->mm.lock);
> }
>
> -static unsigned int swiotlb_max_size(void)
> -{
> -#if IS_ENABLED(CONFIG_SWIOTLB)
> - return rounddown(swiotlb_nr_tbl() << IO_TLB_SHIFT, PAGE_SIZE);
> -#else
> - return 0;
> -#endif
> -}
> -
> static void i915_sg_trim(struct sg_table *orig_st)
> {
> struct sg_table new_st;
> @@ -2267,7 +2258,7 @@ i915_gem_object_get_pages_gtt(struct drm_i915_gem_object *obj)
> struct sgt_iter sgt_iter;
> struct page *page;
> unsigned long last_pfn = 0; /* suppress gcc warning */
> - unsigned int max_segment;
> + unsigned int max_segment = rounddown(i915_sg_segment_size(), PAGE_SIZE);
> int ret;
> gfp_t gfp;
>
> @@ -2278,10 +2269,6 @@ i915_gem_object_get_pages_gtt(struct drm_i915_gem_object *obj)
> GEM_BUG_ON(obj->base.read_domains & I915_GEM_GPU_DOMAINS);
> GEM_BUG_ON(obj->base.write_domain & I915_GEM_GPU_DOMAINS);
>
> - max_segment = swiotlb_max_size();
> - if (!max_segment)
> - max_segment = rounddown(UINT_MAX, PAGE_SIZE);
> -
> st = kmalloc(sizeof(*st), GFP_KERNEL);
> if (st == NULL)
> return ERR_PTR(-ENOMEM);
> diff --git a/drivers/gpu/drm/i915/i915_gem_userptr.c b/drivers/gpu/drm/i915/i915_gem_userptr.c
> index 64261639f547..b4461f1832a6 100644
> --- a/drivers/gpu/drm/i915/i915_gem_userptr.c
> +++ b/drivers/gpu/drm/i915/i915_gem_userptr.c
> @@ -390,36 +390,20 @@ struct get_pages_work {
> struct task_struct *task;
> };
>
> -#if IS_ENABLED(CONFIG_SWIOTLB)
> -#define swiotlb_active() swiotlb_nr_tbl()
> -#else
> -#define swiotlb_active() 0
> -#endif
> -
> static int
> st_set_pages(struct sg_table **st, struct page **pvec, int num_pages)
> {
> - struct scatterlist *sg;
> - int ret, n;
> + int ret;
>
> *st = kmalloc(sizeof(**st), GFP_KERNEL);
> if (*st == NULL)
> return -ENOMEM;
>
> - if (swiotlb_active()) {
> - ret = sg_alloc_table(*st, num_pages, GFP_KERNEL);
> - if (ret)
> - goto err;
> -
> - for_each_sg((*st)->sgl, sg, num_pages, n)
> - sg_set_page(sg, pvec[n], PAGE_SIZE, 0);
> - } else {
> - ret = sg_alloc_table_from_pages(*st, pvec, num_pages,
> - 0, num_pages << PAGE_SHIFT,
> - GFP_KERNEL);
> - if (ret)
> - goto err;
> - }
> + ret = __sg_alloc_table_from_pages(*st, pvec, num_pages, 0,
> + num_pages << PAGE_SHIFT,
Petty:
ret = __sg_alloc_table_from_pages(*st, pvec, num_pages,
pvec + num_pages are paired
0, num_pages << PAGE_SHIFT,
offset + size are paired
i915_sg_segment_size()),
GFP_KERNEL);
And for some reason I always like to see gfp_t last.
Otherwise looks good,
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
-Chris
--
Chris Wilson, Intel Open Source Technology Centre
^ permalink raw reply [flat|nested] 21+ messages in thread
* Re: [Intel-gfx] [PATCH 3/4] lib/scatterlist: Introduce and export __sg_alloc_table_from_pages
2016-11-11 8:50 ` [PATCH 3/4] lib/scatterlist: Introduce and export __sg_alloc_table_from_pages Tvrtko Ursulin
@ 2016-11-11 10:24 ` Chris Wilson
2016-11-11 12:35 ` [PATCH v2 " Tvrtko Ursulin
2016-11-11 14:17 ` [PATCH v3 " Tvrtko Ursulin
0 siblings, 2 replies; 21+ messages in thread
From: Chris Wilson @ 2016-11-11 10:24 UTC (permalink / raw)
To: Tvrtko Ursulin; +Cc: Intel-gfx, Masahiro Yamada, linux-kernel
On Fri, Nov 11, 2016 at 08:50:19AM +0000, Tvrtko Ursulin wrote:
> From: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
>
> Drivers like i915 benefit from being able to control the maxium
> size of the sg coallesced segment while building the scatter-
> gather list.
>
> Introduce and export the __sg_alloc_table_from_pages function
> which will allow it that control.
>
> Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
> Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
> Cc: linux-kernel@vger.kernel.org
> ---
> include/linux/scatterlist.h | 11 +++++----
> lib/scatterlist.c | 55 ++++++++++++++++++++++++++++++++++-----------
> 2 files changed, 49 insertions(+), 17 deletions(-)
>
> diff --git a/include/linux/scatterlist.h b/include/linux/scatterlist.h
> index c981bee1a3ae..29591dbb20fd 100644
> --- a/include/linux/scatterlist.h
> +++ b/include/linux/scatterlist.h
> @@ -261,10 +261,13 @@ void sg_free_table(struct sg_table *);
> int __sg_alloc_table(struct sg_table *, unsigned int, unsigned int,
> struct scatterlist *, gfp_t, sg_alloc_fn *);
> int sg_alloc_table(struct sg_table *, unsigned int, gfp_t);
> -int sg_alloc_table_from_pages(struct sg_table *sgt,
> - struct page **pages, unsigned int n_pages,
> - unsigned int offset, unsigned long size,
> - gfp_t gfp_mask);
> +int __sg_alloc_table_from_pages(struct sg_table *sgt, struct page **pages,
> + unsigned int n_pages, unsigned int offset,
> + unsigned long size, gfp_t gfp_mask,
> + unsigned int max_segment);
Just the question of parameter order, I like gfp_t last :)
And I think offset / size / max_segment tie together.
-Chris
--
Chris Wilson, Intel Open Source Technology Centre
^ permalink raw reply [flat|nested] 21+ messages in thread
* [PATCH v2 3/4] lib/scatterlist: Introduce and export __sg_alloc_table_from_pages
2016-11-11 10:24 ` [Intel-gfx] " Chris Wilson
@ 2016-11-11 12:35 ` Tvrtko Ursulin
2016-11-11 14:17 ` [PATCH v3 " Tvrtko Ursulin
1 sibling, 0 replies; 21+ messages in thread
From: Tvrtko Ursulin @ 2016-11-11 12:35 UTC (permalink / raw)
To: Intel-gfx; +Cc: linux-kernel, Tvrtko Ursulin, Masahiro Yamada, Chris Wilson
From: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Drivers like i915 benefit from being able to control the maxium
size of the sg coallesced segment while building the scatter-
gather list.
Introduce and export the __sg_alloc_table_from_pages function
which will allow it that control.
v2: Reorder parameters. (Chris Wilson)
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: linux-kernel@vger.kernel.org
Cc: Chris Wilson <chris@chris-wilson.co.uk>
---
include/linux/scatterlist.h | 11 +++++----
lib/scatterlist.c | 55 ++++++++++++++++++++++++++++++++++-----------
2 files changed, 49 insertions(+), 17 deletions(-)
diff --git a/include/linux/scatterlist.h b/include/linux/scatterlist.h
index c981bee1a3ae..16b740afeed2 100644
--- a/include/linux/scatterlist.h
+++ b/include/linux/scatterlist.h
@@ -261,10 +261,13 @@ void sg_free_table(struct sg_table *);
int __sg_alloc_table(struct sg_table *, unsigned int, unsigned int,
struct scatterlist *, gfp_t, sg_alloc_fn *);
int sg_alloc_table(struct sg_table *, unsigned int, gfp_t);
-int sg_alloc_table_from_pages(struct sg_table *sgt,
- struct page **pages, unsigned int n_pages,
- unsigned int offset, unsigned long size,
- gfp_t gfp_mask);
+int __sg_alloc_table_from_pages(struct sg_table *sgt, struct page **pages,
+ unsigned int n_pages, unsigned int offset,
+ unsigned long size, unsigned int max_segment,
+ gfp_t gfp_mask);
+int sg_alloc_table_from_pages(struct sg_table *sgt, struct page **pages,
+ unsigned int n_pages, unsigned int offset,
+ unsigned long size, gfp_t gfp_mask);
size_t sg_copy_buffer(struct scatterlist *sgl, unsigned int nents, void *buf,
size_t buflen, off_t skip, bool to_buffer);
diff --git a/lib/scatterlist.c b/lib/scatterlist.c
index de15f369b317..8ee1ece81626 100644
--- a/lib/scatterlist.c
+++ b/lib/scatterlist.c
@@ -370,14 +370,15 @@ int sg_alloc_table(struct sg_table *table, unsigned int nents, gfp_t gfp_mask)
EXPORT_SYMBOL(sg_alloc_table);
/**
- * sg_alloc_table_from_pages - Allocate and initialize an sg table from
- * an array of pages
- * @sgt: The sg table header to use
- * @pages: Pointer to an array of page pointers
- * @n_pages: Number of pages in the pages array
- * @offset: Offset from start of the first page to the start of a buffer
- * @size: Number of valid bytes in the buffer (after offset)
- * @gfp_mask: GFP allocation mask
+ * __sg_alloc_table_from_pages - Allocate and initialize an sg table from
+ * an array of pages
+ * @sgt: The sg table header to use
+ * @pages: Pointer to an array of page pointers
+ * @n_pages: Number of pages in the pages array
+ * @offset: Offset from start of the first page to the start of a buffer
+ * @size: Number of valid bytes in the buffer (after offset)
+ * @max_segment: Maximum size of a single scatterlist node in bytes
+ * @gfp_mask: GFP allocation mask
*
* Description:
* Allocate and initialize an sg table from a list of pages. Contiguous
@@ -389,12 +390,11 @@ EXPORT_SYMBOL(sg_alloc_table);
* Returns:
* 0 on success, negative error on failure
*/
-int sg_alloc_table_from_pages(struct sg_table *sgt,
- struct page **pages, unsigned int n_pages,
- unsigned int offset, unsigned long size,
- gfp_t gfp_mask)
+int __sg_alloc_table_from_pages(struct sg_table *sgt, struct page **pages,
+ unsigned int n_pages, unsigned int offset,
+ unsigned long size, unsigned int max_segment,
+ gfp_t gfp_mask)
{
- const unsigned int max_segment = UINT_MAX;
unsigned int seg_len, chunks;
unsigned int i;
unsigned int cur_page;
@@ -444,6 +444,35 @@ int sg_alloc_table_from_pages(struct sg_table *sgt,
return 0;
}
+EXPORT_SYMBOL(__sg_alloc_table_from_pages);
+
+/**
+ * sg_alloc_table_from_pages - Allocate and initialize an sg table from
+ * an array of pages
+ * @sgt: The sg table header to use
+ * @pages: Pointer to an array of page pointers
+ * @n_pages: Number of pages in the pages array
+ * @offset: Offset from start of the first page to the start of a buffer
+ * @size: Number of valid bytes in the buffer (after offset)
+ * @gfp_mask: GFP allocation mask
+ *
+ * Description:
+ * Allocate and initialize an sg table from a list of pages. Contiguous
+ * ranges of the pages are squashed into a single scatterlist node. A user
+ * may provide an offset at a start and a size of valid data in a buffer
+ * specified by the page array. The returned sg table is released by
+ * sg_free_table.
+ *
+ * Returns:
+ * 0 on success, negative error on failure
+ */
+int sg_alloc_table_from_pages(struct sg_table *sgt, struct page **pages,
+ unsigned int n_pages, unsigned int offset,
+ unsigned long size, gfp_t gfp_mask)
+{
+ return __sg_alloc_table_from_pages(sgt, pages, n_pages, offset,
+ size, gfp_mask, UINT_MAX);
+}
EXPORT_SYMBOL(sg_alloc_table_from_pages);
void __sg_page_iter_start(struct sg_page_iter *piter,
--
2.7.4
^ permalink raw reply related [flat|nested] 21+ messages in thread
* [PATCH v4 4/4] drm/i915: Use __sg_alloc_table_from_pages for userptr allocations
2016-11-11 10:23 ` [PATCH " Chris Wilson
@ 2016-11-11 12:36 ` Tvrtko Ursulin
2016-11-14 9:52 ` Chris Wilson
0 siblings, 1 reply; 21+ messages in thread
From: Tvrtko Ursulin @ 2016-11-11 12:36 UTC (permalink / raw)
To: Intel-gfx; +Cc: linux-kernel, Tvrtko Ursulin, Chris Wilson
From: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
With the addition of __sg_alloc_table_from_pages we can control
the maximum coallescing size and eliminate a separate path for
allocating backing store here.
Similar to 871dfbd67d4e ("drm/i915: Allow compaction upto
SWIOTLB max segment size") this enables more compact sg lists to
be created and so has a beneficial effect on workloads with many
and/or large objects of this class.
v2:
* Rename helper to i915_sg_segment_size and fix swiotlb override.
* Commit message update.
v3:
* Actually include the swiotlb override fix.
v4:
* Regroup parameters a bit. (Chris Wilson)
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> (v2)
---
drivers/gpu/drm/i915/i915_drv.h | 11 +++++++++++
drivers/gpu/drm/i915/i915_gem.c | 15 +--------------
drivers/gpu/drm/i915/i915_gem_userptr.c | 29 +++++++----------------------
3 files changed, 19 insertions(+), 36 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 30777dee3f9c..38a555c9c44b 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -4175,4 +4175,15 @@ int remap_io_mapping(struct vm_area_struct *vma,
__T; \
})
+static inline unsigned int i915_sg_segment_size(void)
+{
+#if IS_ENABLED(CONFIG_SWIOTLB)
+ unsigned int nr_tbl = swiotlb_nr_tbl();
+
+ return nr_tbl > 0 ? nr_tbl << IO_TLB_SHIFT : UINT_MAX;
+#else
+ return UINT_MAX;
+#endif
+}
+
#endif
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 1c20edba7f2a..cb4c188a395c 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2223,15 +2223,6 @@ void __i915_gem_object_put_pages(struct drm_i915_gem_object *obj,
mutex_unlock(&obj->mm.lock);
}
-static unsigned int swiotlb_max_size(void)
-{
-#if IS_ENABLED(CONFIG_SWIOTLB)
- return rounddown(swiotlb_nr_tbl() << IO_TLB_SHIFT, PAGE_SIZE);
-#else
- return 0;
-#endif
-}
-
static void i915_sg_trim(struct sg_table *orig_st)
{
struct sg_table new_st;
@@ -2267,7 +2258,7 @@ i915_gem_object_get_pages_gtt(struct drm_i915_gem_object *obj)
struct sgt_iter sgt_iter;
struct page *page;
unsigned long last_pfn = 0; /* suppress gcc warning */
- unsigned int max_segment;
+ unsigned int max_segment = rounddown(i915_sg_segment_size(), PAGE_SIZE);
int ret;
gfp_t gfp;
@@ -2278,10 +2269,6 @@ i915_gem_object_get_pages_gtt(struct drm_i915_gem_object *obj)
GEM_BUG_ON(obj->base.read_domains & I915_GEM_GPU_DOMAINS);
GEM_BUG_ON(obj->base.write_domain & I915_GEM_GPU_DOMAINS);
- max_segment = swiotlb_max_size();
- if (!max_segment)
- max_segment = rounddown(UINT_MAX, PAGE_SIZE);
-
st = kmalloc(sizeof(*st), GFP_KERNEL);
if (st == NULL)
return ERR_PTR(-ENOMEM);
diff --git a/drivers/gpu/drm/i915/i915_gem_userptr.c b/drivers/gpu/drm/i915/i915_gem_userptr.c
index 64261639f547..f3fcb2d1bde9 100644
--- a/drivers/gpu/drm/i915/i915_gem_userptr.c
+++ b/drivers/gpu/drm/i915/i915_gem_userptr.c
@@ -390,36 +390,21 @@ struct get_pages_work {
struct task_struct *task;
};
-#if IS_ENABLED(CONFIG_SWIOTLB)
-#define swiotlb_active() swiotlb_nr_tbl()
-#else
-#define swiotlb_active() 0
-#endif
-
static int
st_set_pages(struct sg_table **st, struct page **pvec, int num_pages)
{
- struct scatterlist *sg;
- int ret, n;
+ int ret;
*st = kmalloc(sizeof(**st), GFP_KERNEL);
if (*st == NULL)
return -ENOMEM;
- if (swiotlb_active()) {
- ret = sg_alloc_table(*st, num_pages, GFP_KERNEL);
- if (ret)
- goto err;
-
- for_each_sg((*st)->sgl, sg, num_pages, n)
- sg_set_page(sg, pvec[n], PAGE_SIZE, 0);
- } else {
- ret = sg_alloc_table_from_pages(*st, pvec, num_pages,
- 0, num_pages << PAGE_SHIFT,
- GFP_KERNEL);
- if (ret)
- goto err;
- }
+ ret = __sg_alloc_table_from_pages(*st, pvec, num_pages,
+ 0, num_pages << PAGE_SHIFT,
+ i915_sg_segment_size(),
+ GFP_KERNEL);
+ if (ret)
+ goto err;
return 0;
--
2.7.4
^ permalink raw reply related [flat|nested] 21+ messages in thread
* [PATCH v3 3/4] lib/scatterlist: Introduce and export __sg_alloc_table_from_pages
2016-11-11 10:24 ` [Intel-gfx] " Chris Wilson
2016-11-11 12:35 ` [PATCH v2 " Tvrtko Ursulin
@ 2016-11-11 14:17 ` Tvrtko Ursulin
2016-11-14 9:51 ` Chris Wilson
1 sibling, 1 reply; 21+ messages in thread
From: Tvrtko Ursulin @ 2016-11-11 14:17 UTC (permalink / raw)
To: Intel-gfx; +Cc: linux-kernel, Tvrtko Ursulin, Masahiro Yamada, Chris Wilson
From: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Drivers like i915 benefit from being able to control the maxium
size of the sg coallesced segment while building the scatter-
gather list.
Introduce and export the __sg_alloc_table_from_pages function
which will allow it that control.
v2: Reorder parameters. (Chris Wilson)
v3: Fix incomplete reordering in v2.
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: linux-kernel@vger.kernel.org
Cc: Chris Wilson <chris@chris-wilson.co.uk>
---
include/linux/scatterlist.h | 11 +++++----
lib/scatterlist.c | 55 ++++++++++++++++++++++++++++++++++-----------
2 files changed, 49 insertions(+), 17 deletions(-)
diff --git a/include/linux/scatterlist.h b/include/linux/scatterlist.h
index c981bee1a3ae..16b740afeed2 100644
--- a/include/linux/scatterlist.h
+++ b/include/linux/scatterlist.h
@@ -261,10 +261,13 @@ void sg_free_table(struct sg_table *);
int __sg_alloc_table(struct sg_table *, unsigned int, unsigned int,
struct scatterlist *, gfp_t, sg_alloc_fn *);
int sg_alloc_table(struct sg_table *, unsigned int, gfp_t);
-int sg_alloc_table_from_pages(struct sg_table *sgt,
- struct page **pages, unsigned int n_pages,
- unsigned int offset, unsigned long size,
- gfp_t gfp_mask);
+int __sg_alloc_table_from_pages(struct sg_table *sgt, struct page **pages,
+ unsigned int n_pages, unsigned int offset,
+ unsigned long size, unsigned int max_segment,
+ gfp_t gfp_mask);
+int sg_alloc_table_from_pages(struct sg_table *sgt, struct page **pages,
+ unsigned int n_pages, unsigned int offset,
+ unsigned long size, gfp_t gfp_mask);
size_t sg_copy_buffer(struct scatterlist *sgl, unsigned int nents, void *buf,
size_t buflen, off_t skip, bool to_buffer);
diff --git a/lib/scatterlist.c b/lib/scatterlist.c
index de15f369b317..7f4d637d3606 100644
--- a/lib/scatterlist.c
+++ b/lib/scatterlist.c
@@ -370,14 +370,15 @@ int sg_alloc_table(struct sg_table *table, unsigned int nents, gfp_t gfp_mask)
EXPORT_SYMBOL(sg_alloc_table);
/**
- * sg_alloc_table_from_pages - Allocate and initialize an sg table from
- * an array of pages
- * @sgt: The sg table header to use
- * @pages: Pointer to an array of page pointers
- * @n_pages: Number of pages in the pages array
- * @offset: Offset from start of the first page to the start of a buffer
- * @size: Number of valid bytes in the buffer (after offset)
- * @gfp_mask: GFP allocation mask
+ * __sg_alloc_table_from_pages - Allocate and initialize an sg table from
+ * an array of pages
+ * @sgt: The sg table header to use
+ * @pages: Pointer to an array of page pointers
+ * @n_pages: Number of pages in the pages array
+ * @offset: Offset from start of the first page to the start of a buffer
+ * @size: Number of valid bytes in the buffer (after offset)
+ * @max_segment: Maximum size of a single scatterlist node in bytes
+ * @gfp_mask: GFP allocation mask
*
* Description:
* Allocate and initialize an sg table from a list of pages. Contiguous
@@ -389,12 +390,11 @@ EXPORT_SYMBOL(sg_alloc_table);
* Returns:
* 0 on success, negative error on failure
*/
-int sg_alloc_table_from_pages(struct sg_table *sgt,
- struct page **pages, unsigned int n_pages,
- unsigned int offset, unsigned long size,
- gfp_t gfp_mask)
+int __sg_alloc_table_from_pages(struct sg_table *sgt, struct page **pages,
+ unsigned int n_pages, unsigned int offset,
+ unsigned long size, unsigned int max_segment,
+ gfp_t gfp_mask)
{
- const unsigned int max_segment = UINT_MAX;
unsigned int seg_len, chunks;
unsigned int i;
unsigned int cur_page;
@@ -444,6 +444,35 @@ int sg_alloc_table_from_pages(struct sg_table *sgt,
return 0;
}
+EXPORT_SYMBOL(__sg_alloc_table_from_pages);
+
+/**
+ * sg_alloc_table_from_pages - Allocate and initialize an sg table from
+ * an array of pages
+ * @sgt: The sg table header to use
+ * @pages: Pointer to an array of page pointers
+ * @n_pages: Number of pages in the pages array
+ * @offset: Offset from start of the first page to the start of a buffer
+ * @size: Number of valid bytes in the buffer (after offset)
+ * @gfp_mask: GFP allocation mask
+ *
+ * Description:
+ * Allocate and initialize an sg table from a list of pages. Contiguous
+ * ranges of the pages are squashed into a single scatterlist node. A user
+ * may provide an offset at a start and a size of valid data in a buffer
+ * specified by the page array. The returned sg table is released by
+ * sg_free_table.
+ *
+ * Returns:
+ * 0 on success, negative error on failure
+ */
+int sg_alloc_table_from_pages(struct sg_table *sgt, struct page **pages,
+ unsigned int n_pages, unsigned int offset,
+ unsigned long size, gfp_t gfp_mask)
+{
+ return __sg_alloc_table_from_pages(sgt, pages, n_pages, offset,
+ size, UINT_MAX, gfp_mask);
+}
EXPORT_SYMBOL(sg_alloc_table_from_pages);
void __sg_page_iter_start(struct sg_page_iter *piter,
--
2.7.4
^ permalink raw reply related [flat|nested] 21+ messages in thread
* Re: [PATCH v3 3/4] lib/scatterlist: Introduce and export __sg_alloc_table_from_pages
2016-11-11 14:17 ` [PATCH v3 " Tvrtko Ursulin
@ 2016-11-14 9:51 ` Chris Wilson
0 siblings, 0 replies; 21+ messages in thread
From: Chris Wilson @ 2016-11-14 9:51 UTC (permalink / raw)
To: Tvrtko Ursulin; +Cc: Intel-gfx, linux-kernel, Tvrtko Ursulin, Masahiro Yamada
On Fri, Nov 11, 2016 at 02:17:44PM +0000, Tvrtko Ursulin wrote:
> From: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
>
> Drivers like i915 benefit from being able to control the maxium
> size of the sg coallesced segment while building the scatter-
> gather list.
>
> Introduce and export the __sg_alloc_table_from_pages function
> which will allow it that control.
>
> v2: Reorder parameters. (Chris Wilson)
> v3: Fix incomplete reordering in v2.
>
> Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
> Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
> Cc: linux-kernel@vger.kernel.org
> Cc: Chris Wilson <chris@chris-wilson.co.uk>
Works for me,
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
-Chris
--
Chris Wilson, Intel Open Source Technology Centre
^ permalink raw reply [flat|nested] 21+ messages in thread
* Re: [PATCH v4 4/4] drm/i915: Use __sg_alloc_table_from_pages for userptr allocations
2016-11-11 12:36 ` [PATCH v4 " Tvrtko Ursulin
@ 2016-11-14 9:52 ` Chris Wilson
0 siblings, 0 replies; 21+ messages in thread
From: Chris Wilson @ 2016-11-14 9:52 UTC (permalink / raw)
To: Tvrtko Ursulin; +Cc: Intel-gfx, linux-kernel, Tvrtko Ursulin
On Fri, Nov 11, 2016 at 12:36:13PM +0000, Tvrtko Ursulin wrote:
> From: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
>
> With the addition of __sg_alloc_table_from_pages we can control
> the maximum coallescing size and eliminate a separate path for
> allocating backing store here.
>
> Similar to 871dfbd67d4e ("drm/i915: Allow compaction upto
> SWIOTLB max segment size") this enables more compact sg lists to
> be created and so has a beneficial effect on workloads with many
> and/or large objects of this class.
>
> v2:
> * Rename helper to i915_sg_segment_size and fix swiotlb override.
> * Commit message update.
>
> v3:
> * Actually include the swiotlb override fix.
>
> v4:
> * Regroup parameters a bit. (Chris Wilson)
>
> Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
> Cc: Chris Wilson <chris@chris-wilson.co.uk>
> Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> (v2)
(bump)
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
-Chris
--
Chris Wilson, Intel Open Source Technology Centre
^ permalink raw reply [flat|nested] 21+ messages in thread
* Re: [Intel-gfx] [PATCH 1/4] lib/scatterlist: Fix offset type in sg_alloc_table_from_pages
2016-11-11 8:50 ` [PATCH 1/4] lib/scatterlist: Fix offset type in sg_alloc_table_from_pages Tvrtko Ursulin
@ 2016-11-14 9:55 ` Chris Wilson
2016-11-22 14:31 ` Mauro Carvalho Chehab
0 siblings, 1 reply; 21+ messages in thread
From: Chris Wilson @ 2016-11-14 9:55 UTC (permalink / raw)
To: Tvrtko Ursulin
Cc: Intel-gfx, Tomasz Stanislawski, Pawel Osciak, linux-kernel,
Masahiro Yamada, Kyungmin Park, Matt Porter, linux-media,
Alexandre Bounine, Marek Szyprowski
On Fri, Nov 11, 2016 at 08:50:17AM +0000, Tvrtko Ursulin wrote:
> From: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
>
> Scatterlist entries have an unsigned int for the offset so
> correct the sg_alloc_table_from_pages function accordingly.
>
> Since these are offsets withing a page, unsigned int is
> wide enough.
>
> Also converts callers which were using unsigned long locally
> with the lower_32_bits annotation to make it explicitly
> clear what is happening.
>
> v2: Use offset_in_page. (Chris Wilson)
>
> Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
> Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
> Cc: Pawel Osciak <pawel@osciak.com>
> Cc: Marek Szyprowski <m.szyprowski@samsung.com>
> Cc: Kyungmin Park <kyungmin.park@samsung.com>
> Cc: Tomasz Stanislawski <t.stanislaws@samsung.com>
> Cc: Matt Porter <mporter@kernel.crashing.org>
> Cc: Alexandre Bounine <alexandre.bounine@idt.com>
> Cc: linux-media@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Acked-by: Marek Szyprowski <m.szyprowski@samsung.com> (v1)
If there were kerneldoc, it would nicely explain that having an offset
larger then a page is silly when passing in array of pages.
Changes elsewhere look ok (personally I'd be happy with just
offset_in_page(), 4GiB superpages are somebody else's problem :)
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
-Chris
--
Chris Wilson, Intel Open Source Technology Centre
^ permalink raw reply [flat|nested] 21+ messages in thread
* Re: [Intel-gfx] [PATCH 0/4] Compact userptr object backing store allocation
2016-11-11 8:50 [PATCH 0/4] Compact userptr object backing store allocation Tvrtko Ursulin
` (3 preceding siblings ...)
2016-11-11 8:50 ` [PATCH 4/4] drm/i915: Use __sg_alloc_table_from_pages for userptr allocations Tvrtko Ursulin
@ 2016-11-14 11:45 ` Tvrtko Ursulin
2016-11-28 10:23 ` Tvrtko Ursulin
4 siblings, 1 reply; 21+ messages in thread
From: Tvrtko Ursulin @ 2016-11-14 11:45 UTC (permalink / raw)
To: Tvrtko Ursulin, Intel-gfx, Andrew Morton; +Cc: linux-kernel
Hi Andrew,
On 11/11/2016 08:50, Tvrtko Ursulin wrote:
> From: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
>
> Userptr backing store with SWIOTBL active is currently allocated in the same
> inefficient manner, with one sg entry per object page, as what the commit
> 871dfbd67d4e ("drm/i915: Allow compaction upto SWIOTLB max segment size") fixed
> for regular GEM objects.
>
> We can fix that by adding new a __sg_alloc_table_from_pages core function which
> allows us to control the maximum desired coalesced segment size.
>
> Other than that the series starts with two simple fixes to
> sg_alloc_table_from_pages which deal with incorrect data type usage and a
> theoretical overflow condition. Fixing the latter enables easy addition of the
> above mentioned __sg_alloc_table_from_pages.
>
> Tvrtko Ursulin (4):
> lib/scatterlist: Fix offset type in sg_alloc_table_from_pages
> lib/scatterlist: Avoid potential scatterlist entry overflow
> lib/scatterlist: Introduce and export __sg_alloc_table_from_pages
> drm/i915: Use __sg_alloc_table_from_pages for userptr allocations
>
> drivers/gpu/drm/i915/i915_drv.h | 9 +++
> drivers/gpu/drm/i915/i915_gem.c | 15 +----
> drivers/gpu/drm/i915/i915_gem_userptr.c | 28 ++-------
> drivers/media/v4l2-core/videobuf2-dma-contig.c | 4 +-
> drivers/rapidio/devices/rio_mport_cdev.c | 4 +-
> include/linux/scatterlist.h | 11 ++--
> lib/scatterlist.c | 78 ++++++++++++++++++++------
> 7 files changed, 87 insertions(+), 62 deletions(-)
I have three patches to lib/scatterlist.c in this series which has all
been reviewed and tested.
We would like to merge them via the DRM tree if there are no objections?
Kind regards,
Tvrtko
^ permalink raw reply [flat|nested] 21+ messages in thread
* Re: [Intel-gfx] [PATCH 1/4] lib/scatterlist: Fix offset type in sg_alloc_table_from_pages
2016-11-14 9:55 ` [Intel-gfx] " Chris Wilson
@ 2016-11-22 14:31 ` Mauro Carvalho Chehab
0 siblings, 0 replies; 21+ messages in thread
From: Mauro Carvalho Chehab @ 2016-11-22 14:31 UTC (permalink / raw)
To: Chris Wilson
Cc: Tvrtko Ursulin, Intel-gfx, Tomasz Stanislawski, Pawel Osciak,
linux-kernel, Masahiro Yamada, Kyungmin Park, Matt Porter,
linux-media, Alexandre Bounine, Marek Szyprowski
Em Mon, 14 Nov 2016 09:55:48 +0000
Chris Wilson <chris@chris-wilson.co.uk> escreveu:
> On Fri, Nov 11, 2016 at 08:50:17AM +0000, Tvrtko Ursulin wrote:
> > From: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
> >
> > Scatterlist entries have an unsigned int for the offset so
> > correct the sg_alloc_table_from_pages function accordingly.
> >
> > Since these are offsets withing a page, unsigned int is
> > wide enough.
> >
> > Also converts callers which were using unsigned long locally
> > with the lower_32_bits annotation to make it explicitly
> > clear what is happening.
> >
> > v2: Use offset_in_page. (Chris Wilson)
> >
> > Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
> > Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
> > Cc: Pawel Osciak <pawel@osciak.com>
> > Cc: Marek Szyprowski <m.szyprowski@samsung.com>
> > Cc: Kyungmin Park <kyungmin.park@samsung.com>
> > Cc: Tomasz Stanislawski <t.stanislaws@samsung.com>
> > Cc: Matt Porter <mporter@kernel.crashing.org>
> > Cc: Alexandre Bounine <alexandre.bounine@idt.com>
> > Cc: linux-media@vger.kernel.org
> > Cc: linux-kernel@vger.kernel.org
> > Acked-by: Marek Szyprowski <m.szyprowski@samsung.com> (v1)
>
> If there were kerneldoc, it would nicely explain that having an offset
> larger then a page is silly when passing in array of pages.
>
> Changes elsewhere look ok (personally I'd be happy with just
> offset_in_page(), 4GiB superpages are somebody else's problem :)
For the media changes, that looked OK. We don't have any needs
to stream 4GB images nowadays :-)
Reviewed-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
> Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
> -Chris
>
Thanks,
Mauro
^ permalink raw reply [flat|nested] 21+ messages in thread
* Re: [Intel-gfx] [PATCH 0/4] Compact userptr object backing store allocation
2016-11-14 11:45 ` [Intel-gfx] [PATCH 0/4] Compact userptr object backing store allocation Tvrtko Ursulin
@ 2016-11-28 10:23 ` Tvrtko Ursulin
0 siblings, 0 replies; 21+ messages in thread
From: Tvrtko Ursulin @ 2016-11-28 10:23 UTC (permalink / raw)
To: Tvrtko Ursulin, Intel-gfx, Andrew Morton; +Cc: linux-kernel, Chris Wilson
On 14/11/2016 11:45, Tvrtko Ursulin wrote:
>
> Hi Andrew,
>
> On 11/11/2016 08:50, Tvrtko Ursulin wrote:
>> From: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
>>
>> Userptr backing store with SWIOTBL active is currently allocated in
>> the same
>> inefficient manner, with one sg entry per object page, as what the commit
>> 871dfbd67d4e ("drm/i915: Allow compaction upto SWIOTLB max segment
>> size") fixed
>> for regular GEM objects.
>>
>> We can fix that by adding new a __sg_alloc_table_from_pages core
>> function which
>> allows us to control the maximum desired coalesced segment size.
>>
>> Other than that the series starts with two simple fixes to
>> sg_alloc_table_from_pages which deal with incorrect data type usage and a
>> theoretical overflow condition. Fixing the latter enables easy
>> addition of the
>> above mentioned __sg_alloc_table_from_pages.
>>
>> Tvrtko Ursulin (4):
>> lib/scatterlist: Fix offset type in sg_alloc_table_from_pages
>> lib/scatterlist: Avoid potential scatterlist entry overflow
>> lib/scatterlist: Introduce and export __sg_alloc_table_from_pages
>> drm/i915: Use __sg_alloc_table_from_pages for userptr allocations
>>
>> drivers/gpu/drm/i915/i915_drv.h | 9 +++
>> drivers/gpu/drm/i915/i915_gem.c | 15 +----
>> drivers/gpu/drm/i915/i915_gem_userptr.c | 28 ++-------
>> drivers/media/v4l2-core/videobuf2-dma-contig.c | 4 +-
>> drivers/rapidio/devices/rio_mport_cdev.c | 4 +-
>> include/linux/scatterlist.h | 11 ++--
>> lib/scatterlist.c | 78
>> ++++++++++++++++++++------
>> 7 files changed, 87 insertions(+), 62 deletions(-)
>
> I have three patches to lib/scatterlist.c in this series which has all
> been reviewed and tested.
>
> We would like to merge them via the DRM tree if there are no objections?
Excuse me for the re-ping - still looking for an ack to merge these few
patches via the drm tree. (The code in question does not have a
designated maintainer.)
Regards,
Tvrtko
^ permalink raw reply [flat|nested] 21+ messages in thread
* Re: [Intel-gfx] [PATCH 3/4] lib/scatterlist: Introduce and export __sg_alloc_table_from_pages
2017-08-02 23:01 ` Andrew Morton
@ 2017-08-03 9:21 ` Tvrtko Ursulin
0 siblings, 0 replies; 21+ messages in thread
From: Tvrtko Ursulin @ 2017-08-03 9:21 UTC (permalink / raw)
To: Andrew Morton
Cc: Tvrtko Ursulin, Intel-gfx, linux-kernel, Masahiro Yamada,
Ben Widawsky, Vetter, Daniel
On 03/08/2017 00:01, Andrew Morton wrote:
> On Wed, 2 Aug 2017 14:06:39 +0100 Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com> wrote:
>
>>
>> Hi Andrew,
>>
>> We have a couple of small lib/scatterlist.c tidies here, plus exporting
>> the new API which allows drivers to control the maximum coalesced entry
>> as created by __sg_alloc_table_from_pages.
>>
>> I am looking for an ack to merge these three patches via the drm-intel tree.
>>
>>
>> ...
>>
>> On 27/07/2017 10:05, Tvrtko Ursulin wrote:
>>> From: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
>>>
>>> Drivers like i915 benefit from being able to control the maxium
>>> size of the sg coallesced segment while building the scatter-
>
> "coalesced"
Oops, I've had this in other patches in the series. Fixed now.
>>> gather list.
>>>
>>> Introduce and export the __sg_alloc_table_from_pages function
>>> which will allow it that control.
>>>
>>
>> ...
>>
>>> --- a/lib/scatterlist.c
>>> +++ b/lib/scatterlist.c
>>> @@ -370,14 +370,15 @@ int sg_alloc_table(struct sg_table *table, unsigned int nents, gfp_t gfp_mask)
>>> EXPORT_SYMBOL(sg_alloc_table);
>>>
>>> /**
>>> - * sg_alloc_table_from_pages - Allocate and initialize an sg table from
>>> - * an array of pages
>>> - * @sgt: The sg table header to use
>>> - * @pages: Pointer to an array of page pointers
>>> - * @n_pages: Number of pages in the pages array
>>> - * @offset: Offset from start of the first page to the start of a buffer
>>> - * @size: Number of valid bytes in the buffer (after offset)
>>> - * @gfp_mask: GFP allocation mask
>>> + * __sg_alloc_table_from_pages - Allocate and initialize an sg table from
>>> + * an array of pages
>>> + * @sgt: The sg table header to use
>>> + * @pages: Pointer to an array of page pointers
>>> + * @n_pages: Number of pages in the pages array
>>> + * @offset: Offset from start of the first page to the start of a buffer
>>> + * @size: Number of valid bytes in the buffer (after offset)
>>> + * @max_segment: Maximum size of a scatterlist node in bytes (page aligned)
>>> + * @gfp_mask: GFP allocation mask
>>> *
>>> * Description:
>>> * Allocate and initialize an sg table from a list of pages. Contiguous
>
> The Description doesn't describe how this differs from
> sg_alloc_table_from_pages(), although it doesn't seem terribly
> important.
Well spotted, I've fixed this as well.
>>> +
>>> +/**
>>> + * sg_alloc_table_from_pages - Allocate and initialize an sg table from
>>> + * an array of pages
>>> + * @sgt: The sg table header to use
>>> + * @pages: Pointer to an array of page pointers
>>> + * @n_pages: Number of pages in the pages array
>>> + * @offset: Offset from start of the first page to the start of a buffer
>>> + * @size: Number of valid bytes in the buffer (after offset)
>>> + * @gfp_mask: GFP allocation mask
>>> + *
>>> + * Description:
>>> + * Allocate and initialize an sg table from a list of pages. Contiguous
>>> + * ranges of the pages are squashed into a single scatterlist node. A user
>>> + * may provide an offset at a start and a size of valid data in a buffer
>>> + * specified by the page array. The returned sg table is released by
>>> + * sg_free_table.
>>> + *
>>> + * Returns:
>>> + * 0 on success, negative error on failure
>>> + */
>>> +int sg_alloc_table_from_pages(struct sg_table *sgt, struct page **pages,
>>> + unsigned int n_pages, unsigned int offset,
>>> + unsigned long size, gfp_t gfp_mask)
>>> +{
>>> + return __sg_alloc_table_from_pages(sgt, pages, n_pages, offset, size,
>>> + SCATTERLIST_MAX_SEGMENT, gfp_mask);
>>> +}
>
> Making this an inline would save a bunch or stack space in the callers?
>
> One could just add the new arg then run around and update the 10ish
> callers but I guess the new interface is OK.
On the first suggestion - there are other trivial wrappers in
lib/scatterlist.c which could benefit from the same treatment (move to
inline) so I opted not to do this in this patch but will send a follow up.
> Otherwise it's OK by me, please go ahead as proposed.
Thanks a lot!
Regards,
Tvrtko
^ permalink raw reply [flat|nested] 21+ messages in thread
* Re: [Intel-gfx] [PATCH 3/4] lib/scatterlist: Introduce and export __sg_alloc_table_from_pages
2017-08-02 13:06 ` [Intel-gfx] " Tvrtko Ursulin
@ 2017-08-02 23:01 ` Andrew Morton
2017-08-03 9:21 ` Tvrtko Ursulin
0 siblings, 1 reply; 21+ messages in thread
From: Andrew Morton @ 2017-08-02 23:01 UTC (permalink / raw)
To: Tvrtko Ursulin
Cc: Tvrtko Ursulin, Intel-gfx, linux-kernel, Masahiro Yamada,
Ben Widawsky, Vetter, Daniel
On Wed, 2 Aug 2017 14:06:39 +0100 Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com> wrote:
>
> Hi Andrew,
>
> We have a couple of small lib/scatterlist.c tidies here, plus exporting
> the new API which allows drivers to control the maximum coalesced entry
> as created by __sg_alloc_table_from_pages.
>
> I am looking for an ack to merge these three patches via the drm-intel tree.
>
>
> ...
>
> On 27/07/2017 10:05, Tvrtko Ursulin wrote:
> > From: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
> >
> > Drivers like i915 benefit from being able to control the maxium
> > size of the sg coallesced segment while building the scatter-
"coalesced"
> > gather list.
> >
> > Introduce and export the __sg_alloc_table_from_pages function
> > which will allow it that control.
> >
>
> ...
>
> > --- a/lib/scatterlist.c
> > +++ b/lib/scatterlist.c
> > @@ -370,14 +370,15 @@ int sg_alloc_table(struct sg_table *table, unsigned int nents, gfp_t gfp_mask)
> > EXPORT_SYMBOL(sg_alloc_table);
> >
> > /**
> > - * sg_alloc_table_from_pages - Allocate and initialize an sg table from
> > - * an array of pages
> > - * @sgt: The sg table header to use
> > - * @pages: Pointer to an array of page pointers
> > - * @n_pages: Number of pages in the pages array
> > - * @offset: Offset from start of the first page to the start of a buffer
> > - * @size: Number of valid bytes in the buffer (after offset)
> > - * @gfp_mask: GFP allocation mask
> > + * __sg_alloc_table_from_pages - Allocate and initialize an sg table from
> > + * an array of pages
> > + * @sgt: The sg table header to use
> > + * @pages: Pointer to an array of page pointers
> > + * @n_pages: Number of pages in the pages array
> > + * @offset: Offset from start of the first page to the start of a buffer
> > + * @size: Number of valid bytes in the buffer (after offset)
> > + * @max_segment: Maximum size of a scatterlist node in bytes (page aligned)
> > + * @gfp_mask: GFP allocation mask
> > *
> > * Description:
> > * Allocate and initialize an sg table from a list of pages. Contiguous
The Description doesn't describe how this differs from
sg_alloc_table_from_pages(), although it doesn't seem terribly
important.
> > +
> > +/**
> > + * sg_alloc_table_from_pages - Allocate and initialize an sg table from
> > + * an array of pages
> > + * @sgt: The sg table header to use
> > + * @pages: Pointer to an array of page pointers
> > + * @n_pages: Number of pages in the pages array
> > + * @offset: Offset from start of the first page to the start of a buffer
> > + * @size: Number of valid bytes in the buffer (after offset)
> > + * @gfp_mask: GFP allocation mask
> > + *
> > + * Description:
> > + * Allocate and initialize an sg table from a list of pages. Contiguous
> > + * ranges of the pages are squashed into a single scatterlist node. A user
> > + * may provide an offset at a start and a size of valid data in a buffer
> > + * specified by the page array. The returned sg table is released by
> > + * sg_free_table.
> > + *
> > + * Returns:
> > + * 0 on success, negative error on failure
> > + */
> > +int sg_alloc_table_from_pages(struct sg_table *sgt, struct page **pages,
> > + unsigned int n_pages, unsigned int offset,
> > + unsigned long size, gfp_t gfp_mask)
> > +{
> > + return __sg_alloc_table_from_pages(sgt, pages, n_pages, offset, size,
> > + SCATTERLIST_MAX_SEGMENT, gfp_mask);
> > +}
Making this an inline would save a bunch or stack space in the callers?
One could just add the new arg then run around and update the 10ish
callers but I guess the new interface is OK.
Otherwise it's OK by me, please go ahead as proposed.
^ permalink raw reply [flat|nested] 21+ messages in thread
* Re: [Intel-gfx] [PATCH 3/4] lib/scatterlist: Introduce and export __sg_alloc_table_from_pages
2017-07-27 9:05 ` [PATCH 3/4] lib/scatterlist: Introduce and export __sg_alloc_table_from_pages Tvrtko Ursulin
@ 2017-08-02 13:06 ` Tvrtko Ursulin
2017-08-02 23:01 ` Andrew Morton
0 siblings, 1 reply; 21+ messages in thread
From: Tvrtko Ursulin @ 2017-08-02 13:06 UTC (permalink / raw)
To: Tvrtko Ursulin, Intel-gfx
Cc: linux-kernel, Masahiro Yamada, Ben Widawsky, Andrew Morton,
Vetter, Daniel
Hi Andrew,
We have a couple of small lib/scatterlist.c tidies here, plus exporting
the new API which allows drivers to control the maximum coalesced entry
as created by __sg_alloc_table_from_pages.
I am looking for an ack to merge these three patches via the drm-intel tree.
Regards,
Tvrtko
On 27/07/2017 10:05, Tvrtko Ursulin wrote:
> From: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
>
> Drivers like i915 benefit from being able to control the maxium
> size of the sg coallesced segment while building the scatter-
> gather list.
>
> Introduce and export the __sg_alloc_table_from_pages function
> which will allow it that control.
>
> v2: Reorder parameters. (Chris Wilson)
> v3: Fix incomplete reordering in v2.
> v4: max_segment needs to be page aligned.
> v5: Rebase.
> v6: Rebase.
>
> Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
> Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
> Cc: linux-kernel@vger.kernel.org
> Cc: Chris Wilson <chris@chris-wilson.co.uk>
> Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> (v2)
> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
> ---
> include/linux/scatterlist.h | 11 +++++----
> lib/scatterlist.c | 58 +++++++++++++++++++++++++++++++++++----------
> 2 files changed, 52 insertions(+), 17 deletions(-)
>
> diff --git a/include/linux/scatterlist.h b/include/linux/scatterlist.h
> index 6dd2ddbc6230..874b50c232de 100644
> --- a/include/linux/scatterlist.h
> +++ b/include/linux/scatterlist.h
> @@ -267,10 +267,13 @@ void sg_free_table(struct sg_table *);
> int __sg_alloc_table(struct sg_table *, unsigned int, unsigned int,
> struct scatterlist *, gfp_t, sg_alloc_fn *);
> int sg_alloc_table(struct sg_table *, unsigned int, gfp_t);
> -int sg_alloc_table_from_pages(struct sg_table *sgt,
> - struct page **pages, unsigned int n_pages,
> - unsigned int offset, unsigned long size,
> - gfp_t gfp_mask);
> +int __sg_alloc_table_from_pages(struct sg_table *sgt, struct page **pages,
> + unsigned int n_pages, unsigned int offset,
> + unsigned long size, unsigned int max_segment,
> + gfp_t gfp_mask);
> +int sg_alloc_table_from_pages(struct sg_table *sgt, struct page **pages,
> + unsigned int n_pages, unsigned int offset,
> + unsigned long size, gfp_t gfp_mask);
>
> size_t sg_copy_buffer(struct scatterlist *sgl, unsigned int nents, void *buf,
> size_t buflen, off_t skip, bool to_buffer);
> diff --git a/lib/scatterlist.c b/lib/scatterlist.c
> index 7b2e74da2c44..1a5900f9a057 100644
> --- a/lib/scatterlist.c
> +++ b/lib/scatterlist.c
> @@ -370,14 +370,15 @@ int sg_alloc_table(struct sg_table *table, unsigned int nents, gfp_t gfp_mask)
> EXPORT_SYMBOL(sg_alloc_table);
>
> /**
> - * sg_alloc_table_from_pages - Allocate and initialize an sg table from
> - * an array of pages
> - * @sgt: The sg table header to use
> - * @pages: Pointer to an array of page pointers
> - * @n_pages: Number of pages in the pages array
> - * @offset: Offset from start of the first page to the start of a buffer
> - * @size: Number of valid bytes in the buffer (after offset)
> - * @gfp_mask: GFP allocation mask
> + * __sg_alloc_table_from_pages - Allocate and initialize an sg table from
> + * an array of pages
> + * @sgt: The sg table header to use
> + * @pages: Pointer to an array of page pointers
> + * @n_pages: Number of pages in the pages array
> + * @offset: Offset from start of the first page to the start of a buffer
> + * @size: Number of valid bytes in the buffer (after offset)
> + * @max_segment: Maximum size of a scatterlist node in bytes (page aligned)
> + * @gfp_mask: GFP allocation mask
> *
> * Description:
> * Allocate and initialize an sg table from a list of pages. Contiguous
> @@ -389,16 +390,18 @@ EXPORT_SYMBOL(sg_alloc_table);
> * Returns:
> * 0 on success, negative error on failure
> */
> -int sg_alloc_table_from_pages(struct sg_table *sgt,
> - struct page **pages, unsigned int n_pages,
> - unsigned int offset, unsigned long size,
> - gfp_t gfp_mask)
> +int __sg_alloc_table_from_pages(struct sg_table *sgt, struct page **pages,
> + unsigned int n_pages, unsigned int offset,
> + unsigned long size, unsigned int max_segment,
> + gfp_t gfp_mask)
> {
> - const unsigned int max_segment = SCATTERLIST_MAX_SEGMENT;
> unsigned int chunks, cur_page, seg_len, i;
> int ret;
> struct scatterlist *s;
>
> + if (WARN_ON(!max_segment || offset_in_page(max_segment)))
> + return -EINVAL;
> +
> /* compute number of contiguous chunks */
> chunks = 1;
> seg_len = 0;
> @@ -440,6 +443,35 @@ int sg_alloc_table_from_pages(struct sg_table *sgt,
>
> return 0;
> }
> +EXPORT_SYMBOL(__sg_alloc_table_from_pages);
> +
> +/**
> + * sg_alloc_table_from_pages - Allocate and initialize an sg table from
> + * an array of pages
> + * @sgt: The sg table header to use
> + * @pages: Pointer to an array of page pointers
> + * @n_pages: Number of pages in the pages array
> + * @offset: Offset from start of the first page to the start of a buffer
> + * @size: Number of valid bytes in the buffer (after offset)
> + * @gfp_mask: GFP allocation mask
> + *
> + * Description:
> + * Allocate and initialize an sg table from a list of pages. Contiguous
> + * ranges of the pages are squashed into a single scatterlist node. A user
> + * may provide an offset at a start and a size of valid data in a buffer
> + * specified by the page array. The returned sg table is released by
> + * sg_free_table.
> + *
> + * Returns:
> + * 0 on success, negative error on failure
> + */
> +int sg_alloc_table_from_pages(struct sg_table *sgt, struct page **pages,
> + unsigned int n_pages, unsigned int offset,
> + unsigned long size, gfp_t gfp_mask)
> +{
> + return __sg_alloc_table_from_pages(sgt, pages, n_pages, offset, size,
> + SCATTERLIST_MAX_SEGMENT, gfp_mask);
> +}
> EXPORT_SYMBOL(sg_alloc_table_from_pages);
>
> void __sg_page_iter_start(struct sg_page_iter *piter,
>
^ permalink raw reply [flat|nested] 21+ messages in thread
end of thread, other threads:[~2017-08-03 9:21 UTC | newest]
Thread overview: 21+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2016-11-11 8:50 [PATCH 0/4] Compact userptr object backing store allocation Tvrtko Ursulin
2016-11-11 8:50 ` [PATCH 1/4] lib/scatterlist: Fix offset type in sg_alloc_table_from_pages Tvrtko Ursulin
2016-11-14 9:55 ` [Intel-gfx] " Chris Wilson
2016-11-22 14:31 ` Mauro Carvalho Chehab
2016-11-11 8:50 ` [PATCH 2/4] lib/scatterlist: Avoid potential scatterlist entry overflow Tvrtko Ursulin
2016-11-11 10:19 ` [Intel-gfx] " Chris Wilson
2016-11-11 8:50 ` [PATCH 3/4] lib/scatterlist: Introduce and export __sg_alloc_table_from_pages Tvrtko Ursulin
2016-11-11 10:24 ` [Intel-gfx] " Chris Wilson
2016-11-11 12:35 ` [PATCH v2 " Tvrtko Ursulin
2016-11-11 14:17 ` [PATCH v3 " Tvrtko Ursulin
2016-11-14 9:51 ` Chris Wilson
2016-11-11 8:50 ` [PATCH 4/4] drm/i915: Use __sg_alloc_table_from_pages for userptr allocations Tvrtko Ursulin
2016-11-11 8:59 ` [PATCH v3 " Tvrtko Ursulin
2016-11-11 10:23 ` [PATCH " Chris Wilson
2016-11-11 12:36 ` [PATCH v4 " Tvrtko Ursulin
2016-11-14 9:52 ` Chris Wilson
2016-11-14 11:45 ` [Intel-gfx] [PATCH 0/4] Compact userptr object backing store allocation Tvrtko Ursulin
2016-11-28 10:23 ` Tvrtko Ursulin
[not found] <20170727090504.15812-1-tvrtko.ursulin@linux.intel.com>
2017-07-27 9:05 ` [PATCH 3/4] lib/scatterlist: Introduce and export __sg_alloc_table_from_pages Tvrtko Ursulin
2017-08-02 13:06 ` [Intel-gfx] " Tvrtko Ursulin
2017-08-02 23:01 ` Andrew Morton
2017-08-03 9:21 ` Tvrtko Ursulin
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