drm/ttm: Use GFP_TRANSHUGE_LIGHT for allocating huge pages

GFP_TRANSHUGE tries very hard to allocate huge pages, which can result
in long delays with high memory pressure. I have observed firefox
freezing for up to around a minute due to this while restic was taking
a full system backup.

Since we don't really need huge pages, use GFP_TRANSHUGE_LIGHT |
__GFP_NORETRY instead, in order to fail quickly when there are no huge
pages available.

Set __GFP_KSWAPD_RECLAIM as well, in order for huge pages to be freed
up in the background if necessary.

With these changes, I'm no longer seeing freezes during a restic backup.

Cc: stable@vger.kernel.org
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Michel Dänzer <michel.daenzer@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
This commit is contained in:
Michel Dänzer 2018-04-25 17:32:10 +02:00 committed by Alex Deucher
parent bd4caed47a
commit da291320ba
2 changed files with 10 additions and 4 deletions

View File

@ -910,7 +910,8 @@ static int ttm_get_pages(struct page **pages, unsigned npages, int flags,
while (npages >= HPAGE_PMD_NR) {
gfp_t huge_flags = gfp_flags;
huge_flags |= GFP_TRANSHUGE;
huge_flags |= GFP_TRANSHUGE_LIGHT | __GFP_NORETRY |
__GFP_KSWAPD_RECLAIM;
huge_flags &= ~__GFP_MOVABLE;
huge_flags &= ~__GFP_COMP;
p = alloc_pages(huge_flags, HPAGE_PMD_ORDER);
@ -1027,11 +1028,15 @@ int ttm_page_alloc_init(struct ttm_mem_global *glob, unsigned max_pages)
GFP_USER | GFP_DMA32, "uc dma", 0);
ttm_page_pool_init_locked(&_manager->wc_pool_huge,
GFP_TRANSHUGE & ~(__GFP_MOVABLE | __GFP_COMP),
(GFP_TRANSHUGE_LIGHT | __GFP_NORETRY |
__GFP_KSWAPD_RECLAIM) &
~(__GFP_MOVABLE | __GFP_COMP),
"wc huge", order);
ttm_page_pool_init_locked(&_manager->uc_pool_huge,
GFP_TRANSHUGE & ~(__GFP_MOVABLE | __GFP_COMP)
(GFP_TRANSHUGE_LIGHT | __GFP_NORETRY |
__GFP_KSWAPD_RECLAIM) &
~(__GFP_MOVABLE | __GFP_COMP)
, "uc huge", order);
_manager->options.max_size = max_pages;

View File

@ -910,7 +910,8 @@ static gfp_t ttm_dma_pool_gfp_flags(struct ttm_dma_tt *ttm_dma, bool huge)
gfp_flags |= __GFP_ZERO;
if (huge) {
gfp_flags |= GFP_TRANSHUGE;
gfp_flags |= GFP_TRANSHUGE_LIGHT | __GFP_NORETRY |
__GFP_KSWAPD_RECLAIM;
gfp_flags &= ~__GFP_MOVABLE;
gfp_flags &= ~__GFP_COMP;
}