* [PATCH v2] drm/ttm: Fix GPU MM stats during pool shrinking
@ 2026-05-02 6:53 Matthew Brost
2026-05-02 8:14 ` Kenneth Crudup
0 siblings, 1 reply; 4+ messages in thread
From: Matthew Brost @ 2026-05-02 6:53 UTC (permalink / raw)
To: intel-xe, dri-devel
Cc: Kenneth Crudup, Christian Koenig, Huang Rui, Matthew Auld,
David Airlie
TTM pool shrinking frees pages by calling __free_pages() directly,
which bypasses updates to NR_GPU_ACTIVE and leaves GPU MM accounting
out of sync.
Introduce a helper, __free_pages_gpu_account(), and use it for all page
frees in ttm_pool.c so GPU MM statistics are updated consistently.
Reported-by: Kenneth Crudup <kenny@panix.com>
Fixes: ae80122f3896 ("drm/ttm: use gpu mm stats to track gpu memory allocations. (v4)")
Cc: Christian Koenig <christian.koenig@amd.com>
Cc: Huang Rui <ray.huang@amd.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: David Airlie <airlied@gmail.com>
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
---
v2:
- Replace put_page() with __free_pages_gpu_account() (Kenneth)
---
drivers/gpu/drm/ttm/ttm_pool.c | 18 ++++++++++++------
1 file changed, 12 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/ttm/ttm_pool.c b/drivers/gpu/drm/ttm/ttm_pool.c
index 26a3689e5fd9..278bbe7a11ad 100644
--- a/drivers/gpu/drm/ttm/ttm_pool.c
+++ b/drivers/gpu/drm/ttm/ttm_pool.c
@@ -206,6 +206,14 @@ static struct page *ttm_pool_alloc_page(struct ttm_pool *pool, gfp_t gfp_flags,
return NULL;
}
+static void __free_pages_gpu_account(struct page *p, unsigned int order,
+ bool reclaim)
+{
+ mod_lruvec_page_state(p, reclaim ? NR_GPU_RECLAIM : NR_GPU_ACTIVE,
+ -(1 << order));
+ __free_pages(p, order);
+}
+
/* Reset the caching and pages of size 1 << order */
static void ttm_pool_free_page(struct ttm_pool *pool, enum ttm_caching caching,
unsigned int order, struct page *p, bool reclaim)
@@ -223,9 +231,7 @@ static void ttm_pool_free_page(struct ttm_pool *pool, enum ttm_caching caching,
#endif
if (!pool || !ttm_pool_uses_dma_alloc(pool)) {
- mod_lruvec_page_state(p, reclaim ? NR_GPU_RECLAIM : NR_GPU_ACTIVE,
- -(1 << order));
- __free_pages(p, order);
+ __free_pages_gpu_account(p, order, reclaim);
return;
}
@@ -606,7 +612,7 @@ static int ttm_pool_restore_commit(struct ttm_pool_tt_restore *restore,
*/
ttm_pool_split_for_swap(restore->pool, p);
copy_highpage(restore->alloced_page + i, p);
- __free_pages(p, 0);
+ __free_pages_gpu_account(p, 0, false);
}
restore->restored_pages++;
@@ -1068,7 +1074,7 @@ long ttm_pool_backup(struct ttm_pool *pool, struct ttm_tt *tt,
if (flags->purge) {
shrunken += num_pages;
page->private = 0;
- __free_pages(page, order);
+ __free_pages_gpu_account(page, order, false);
memset(tt->pages + i, 0,
num_pages * sizeof(*tt->pages));
}
@@ -1109,7 +1115,7 @@ long ttm_pool_backup(struct ttm_pool *pool, struct ttm_tt *tt,
}
handle = shandle;
tt->pages[i] = ttm_backup_handle_to_page_ptr(handle);
- put_page(page);
+ __free_pages_gpu_account(page, 0, false);
shrunken++;
}
--
2.34.1
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH v2] drm/ttm: Fix GPU MM stats during pool shrinking
2026-05-02 6:53 [PATCH v2] drm/ttm: Fix GPU MM stats during pool shrinking Matthew Brost
@ 2026-05-02 8:14 ` Kenneth Crudup
2026-05-04 3:56 ` Dave Airlie
0 siblings, 1 reply; 4+ messages in thread
From: Kenneth Crudup @ 2026-05-02 8:14 UTC (permalink / raw)
To: Matthew Brost, intel-xe, dri-devel
Cc: Christian Koenig, Huang Rui, Matthew Auld, David Airlie
On 5/1/26 23:53, Matthew Brost wrote:
> TTM pool shrinking frees pages by calling __free_pages() directly,
> which bypasses updates to NR_GPU_ACTIVE and leaves GPU MM accounting
> out of sync.
>
> Introduce a helper, __free_pages_gpu_account(), and use it for all page
> frees in ttm_pool.c so GPU MM statistics are updated consistently.
>
> Reported-by: Kenneth Crudup <kenny@panix.com>
> Fixes: ae80122f3896 ("drm/ttm: use gpu mm stats to track gpu memory allocations. (v4)")
> Cc: Christian Koenig <christian.koenig@amd.com>
> Cc: Huang Rui <ray.huang@amd.com>
> Cc: Matthew Auld <matthew.auld@intel.com>
> Cc: David Airlie <airlied@gmail.com>
> Cc: dri-devel@lists.freedesktop.org
> Signed-off-by: Matthew Brost <matthew.brost@intel.com>
>
> ---
>
> v2:
Tested-By: Kenneth R. Crudup <kenny@panix.com>
I think this one got it right ... this is after two bonnie++ runs:
----
SwapFree: 33554428 kB
MemTotal: 32345768 kB
GPUActive: 676092 kB
GPUReclaim: 584272 kB
SwapFree: 33554428 kB
MemTotal: 32345768 kB
GPUActive: 750396 kB
GPUReclaim: 516348 kB
SwapFree: 33554428 kB
MemTotal: 32345768 kB
GPUActive: 801996 kB
GPUReclaim: 478756 kB
SwapFree: 33554428 kB
MemTotal: 32345768 kB
GPUActive: 794224 kB
GPUReclaim: 481624 kB
SwapFree: 33554428 kB
MemTotal: 32345768 kB
GPUActive: 351336 kB
GPUReclaim: 400 kB
SwapFree: 33554428 kB
MemTotal: 32345768 kB
GPUActive: 1015624 kB
GPUReclaim: 72 kB
SwapFree: 33554428 kB
MemTotal: 32345768 kB
GPUActive: 583176 kB
GPUReclaim: 48 kB
SwapFree: 33554428 kB
MemTotal: 32345768 kB
GPUActive: 737852 kB
GPUReclaim: 2524 kB
SwapFree: 33554428 kB
MemTotal: 32345768 kB
GPUActive: 1041056 kB
GPUReclaim: 308 kB
SwapFree: 33554428 kB
MemTotal: 32345768 kB
GPUActive: 1356568 kB
GPUReclaim: 109992 kB
SwapFree: 33554428 kB
MemTotal: 32345768 kB
GPUActive: 1181732 kB
GPUReclaim: 39000 kB
SwapFree: 33554428 kB
MemTotal: 32345768 kB
GPUActive: 989900 kB
GPUReclaim: 68 kB
SwapFree: 33554428 kB
MemTotal: 32345768 kB
GPUActive: 486720 kB
GPUReclaim: 544 kB
SwapFree: 33554428 kB
MemTotal: 32345768 kB
GPUActive: 687628 kB
GPUReclaim: 2280 kB
SwapFree: 33554428 kB
MemTotal: 32345768 kB
GPUActive: 634060 kB
GPUReclaim: 1000 kB
SwapFree: 33554428 kB
MemTotal: 32345768 kB
GPUActive: 1030168 kB
GPUReclaim: 1696 kB
SwapFree: 33554428 kB
MemTotal: 32345768 kB
GPUActive: 1323464 kB
GPUReclaim: 1392 kB
SwapFree: 33554428 kB
MemTotal: 32345768 kB
GPUActive: 1452340 kB
GPUReclaim: 20024 kB
----
-Kenny "yeah, I don't sleep much either" Crudup
--
Kenneth R. Crudup / Sr. SW Engineer, Scott County Consulting, Orange
County CA
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v2] drm/ttm: Fix GPU MM stats during pool shrinking
2026-05-02 8:14 ` Kenneth Crudup
@ 2026-05-04 3:56 ` Dave Airlie
2026-05-04 4:09 ` Matthew Brost
0 siblings, 1 reply; 4+ messages in thread
From: Dave Airlie @ 2026-05-04 3:56 UTC (permalink / raw)
To: Kenneth Crudup
Cc: Matthew Brost, intel-xe, dri-devel, Christian Koenig, Huang Rui,
Matthew Auld
On Sat, 2 May 2026 at 18:14, Kenneth Crudup <kenny@panix.com> wrote:
>
>
>
> On 5/1/26 23:53, Matthew Brost wrote:
> > TTM pool shrinking frees pages by calling __free_pages() directly,
> > which bypasses updates to NR_GPU_ACTIVE and leaves GPU MM accounting
> > out of sync.
> >
> > Introduce a helper, __free_pages_gpu_account(), and use it for all page
> > frees in ttm_pool.c so GPU MM statistics are updated consistently.
> >
> > Reported-by: Kenneth Crudup <kenny@panix.com>
> > Fixes: ae80122f3896 ("drm/ttm: use gpu mm stats to track gpu memory allocations. (v4)")
> > Cc: Christian Koenig <christian.koenig@amd.com>
> > Cc: Huang Rui <ray.huang@amd.com>
> > Cc: Matthew Auld <matthew.auld@intel.com>
> > Cc: David Airlie <airlied@gmail.com>
> > Cc: dri-devel@lists.freedesktop.org
> > Signed-off-by: Matthew Brost <matthew.brost@intel.com>
> >
> > ---
> >
> > v2:
Oops, good catch,
Reviewed-by: Dave Airlie <airlied@redhat.com>
Dave.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v2] drm/ttm: Fix GPU MM stats during pool shrinking
2026-05-04 3:56 ` Dave Airlie
@ 2026-05-04 4:09 ` Matthew Brost
0 siblings, 0 replies; 4+ messages in thread
From: Matthew Brost @ 2026-05-04 4:09 UTC (permalink / raw)
To: Dave Airlie
Cc: Kenneth Crudup, intel-xe, dri-devel, Christian Koenig, Huang Rui,
Matthew Auld
On Mon, May 04, 2026 at 01:56:25PM +1000, Dave Airlie wrote:
> On Sat, 2 May 2026 at 18:14, Kenneth Crudup <kenny@panix.com> wrote:
> >
> >
> >
> > On 5/1/26 23:53, Matthew Brost wrote:
> > > TTM pool shrinking frees pages by calling __free_pages() directly,
> > > which bypasses updates to NR_GPU_ACTIVE and leaves GPU MM accounting
> > > out of sync.
> > >
> > > Introduce a helper, __free_pages_gpu_account(), and use it for all page
> > > frees in ttm_pool.c so GPU MM statistics are updated consistently.
> > >
> > > Reported-by: Kenneth Crudup <kenny@panix.com>
> > > Fixes: ae80122f3896 ("drm/ttm: use gpu mm stats to track gpu memory allocations. (v4)")
> > > Cc: Christian Koenig <christian.koenig@amd.com>
> > > Cc: Huang Rui <ray.huang@amd.com>
> > > Cc: Matthew Auld <matthew.auld@intel.com>
> > > Cc: David Airlie <airlied@gmail.com>
> > > Cc: dri-devel@lists.freedesktop.org
> > > Signed-off-by: Matthew Brost <matthew.brost@intel.com>
> > >
> > > ---
> > >
> > > v2:
>
> Oops, good catch,
>
> Reviewed-by: Dave Airlie <airlied@redhat.com>
Thanks! Merged to drm-misc-fixes.
Matt
>
> Dave.
^ permalink raw reply [flat|nested] 4+ messages in thread
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2026-05-02 6:53 [PATCH v2] drm/ttm: Fix GPU MM stats during pool shrinking Matthew Brost
2026-05-02 8:14 ` Kenneth Crudup
2026-05-04 3:56 ` Dave Airlie
2026-05-04 4:09 ` Matthew Brost
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