On 2024-04-15 9:48, Christian König wrote:
From: Christian König <ckoenig.leichtzumerken@xxxxxxxxx>
We only pool write combined and uncached allocations because they
require extra overhead on allocation and release.
If we also pool cached NUMA it not only means some extra unnecessary
overhead, but also that under memory pressure it can happen that
pages from the wrong NUMA node enters the pool and are re-used
over and over again.
This can lead to performance reduction after running into memory
pressure.
v2: restructure and cleanup the code a bit from the internal hack to
test this.
Signed-off-by: Christian König <christian.koenig@xxxxxxx>
Fixes: 4482d3c94d7f ("drm/ttm: add NUMA node id to the pool")
CC: stable@xxxxxxxxxxxxxxx
---
drivers/gpu/drm/ttm/ttm_pool.c | 38 +++++++++++++++++++++++++---------
1 file changed, 28 insertions(+), 10 deletions(-)
diff --git a/drivers/gpu/drm/ttm/ttm_pool.c b/drivers/gpu/drm/ttm/ttm_pool.c
index 112438d965ff..6e1fd6985ffc 100644
--- a/drivers/gpu/drm/ttm/ttm_pool.c
+++ b/drivers/gpu/drm/ttm/ttm_pool.c
@@ -288,17 +288,23 @@ static struct ttm_pool_type *ttm_pool_select_type(struct ttm_pool *pool,
enum ttm_caching caching,
unsigned int order)
{
- if (pool->use_dma_alloc || pool->nid != NUMA_NO_NODE)
+ if (pool->use_dma_alloc)
return &pool->caching[caching].orders[order];
#ifdef CONFIG_X86
switch (caching) {
case ttm_write_combined:
+ if (pool->nid != NUMA_NO_NODE)
+ return &pool->caching[caching].orders[order];
Doesn't this break USWC allocations on NUMA systems, where we set a NUMA
node for the default pool (at least we were planning to at some point)?
Regards,
Felix
+
if (pool->use_dma32)
return &global_dma32_write_combined[order];
return &global_write_combined[order];
case ttm_uncached:
+ if (pool->nid != NUMA_NO_NODE)
+ return &pool->caching[caching].orders[order];
+
if (pool->use_dma32)
return &global_dma32_uncached[order];
@@ -566,11 +572,17 @@ void ttm_pool_init(struct ttm_pool *pool, struct device *dev,
pool->use_dma_alloc = use_dma_alloc;
pool->use_dma32 = use_dma32;
- if (use_dma_alloc || nid != NUMA_NO_NODE) {
- for (i = 0; i < TTM_NUM_CACHING_TYPES; ++i)
- for (j = 0; j < NR_PAGE_ORDERS; ++j)
- ttm_pool_type_init(&pool->caching[i].orders[j],
- pool, i, j);
+ for (i = 0; i < TTM_NUM_CACHING_TYPES; ++i) {
+ for (j = 0; j < NR_PAGE_ORDERS; ++j) {
+ struct ttm_pool_type *pt;
+
+ /* Initialize only pool types which are actually used */
+ pt = ttm_pool_select_type(pool, i, j);
+ if (pt != &pool->caching[i].orders[j])
+ continue;
+
+ ttm_pool_type_init(pt, pool, i, j);
+ }
}
}
EXPORT_SYMBOL(ttm_pool_init);
@@ -599,10 +611,16 @@ void ttm_pool_fini(struct ttm_pool *pool)
{
unsigned int i, j;
- if (pool->use_dma_alloc || pool->nid != NUMA_NO_NODE) {
- for (i = 0; i < TTM_NUM_CACHING_TYPES; ++i)
- for (j = 0; j < NR_PAGE_ORDERS; ++j)
- ttm_pool_type_fini(&pool->caching[i].orders[j]);
+ for (i = 0; i < TTM_NUM_CACHING_TYPES; ++i) {
+ for (j = 0; j < NR_PAGE_ORDERS; ++j) {
+ struct ttm_pool_type *pt;
+
+ pt = ttm_pool_select_type(pool, i, j);
+ if (pt != &pool->caching[i].orders[j])
+ continue;
+
+ ttm_pool_type_fini(pt);
+ }
}
/* We removed the pool types from the LRU, but we need to also make sure
