Use vma_alloc_folio_hints() and check PGHINT_ZEROED to skip folio_zero_user() in the mTHP anonymous page allocation path when the page is already zeroed.
Signed-off-by: Michael S. Tsirkin <[email protected]> Assisted-by: Claude:claude-opus-4-6 Assisted-by: cursor-agent:GPT-5.4-xhigh --- mm/memory.c | 14 +++++--------- 1 file changed, 5 insertions(+), 9 deletions(-) diff --git a/mm/memory.c b/mm/memory.c index c65e82c86fed..066e2c9781dc 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -5179,8 +5179,10 @@ static struct folio *alloc_anon_folio(struct vm_fault *vmf) /* Try allocating the highest of the remaining orders. */ gfp = vma_thp_gfp_mask(vma); while (orders) { + pghint_t hints; + addr = ALIGN_DOWN(vmf->address, PAGE_SIZE << order); - folio = vma_alloc_folio(gfp, order, vma, addr); + folio = vma_alloc_folio_hints(gfp, order, vma, addr, &hints); if (folio) { if (mem_cgroup_charge(folio, vma->vm_mm, gfp)) { count_mthp_stat(order, MTHP_STAT_ANON_FAULT_FALLBACK_CHARGE); @@ -5188,14 +5190,8 @@ static struct folio *alloc_anon_folio(struct vm_fault *vmf) goto next; } folio_throttle_swaprate(folio, gfp); - /* - * When a folio is not zeroed during allocation - * (__GFP_ZERO not used) or user folios require special - * handling, folio_zero_user() is used to make sure - * that the page corresponding to the faulting address - * will be hot in the cache after zeroing. - */ - if (user_alloc_needs_zeroing()) + if (user_alloc_needs_zeroing() && + !(hints & PGHINT_ZEROED)) folio_zero_user(folio, vmf->address); return folio; } -- MST
