From: =?UTF-8?q?Michel=20D=C3=A4nzer?= Date: Wed, 25 Apr 2018 17:32:10 +0200 Subject: drm/ttm: Use GFP_TRANSHUGE_LIGHT for allocating huge pages MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Git-commit: da291320baec914f0bb4e65a9dccb86bd6c728f2 Patch-mainline: v4.17-rc5 References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166 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 Signed-off-by: Michel Dänzer Signed-off-by: Alex Deucher Acked-by: Petr Tesarik --- drivers/gpu/drm/ttm/ttm_page_alloc.c | 11 ++++++++--- drivers/gpu/drm/ttm/ttm_page_alloc_dma.c | 3 ++- 2 files changed, 10 insertions(+), 4 deletions(-) --- a/drivers/gpu/drm/ttm/ttm_page_alloc.c +++ b/drivers/gpu/drm/ttm/ttm_page_alloc.c @@ -910,7 +910,8 @@ static int ttm_get_pages(struct page **p 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_g 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; --- a/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c +++ b/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c @@ -910,7 +910,8 @@ static gfp_t ttm_dma_pool_gfp_flags(stru 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; }