From 4d1b3416659be70a2251b494e85e25978de06519 Mon Sep 17 00:00:00 2001 From: Pedro Falcato Date: Sat, 17 Aug 2024 01:18:28 +0100 Subject: [PATCH] mm: move can_modify_vma to mm/vma.h Patch series "mm: Optimize mseal checks", v3. Optimize mseal checks by removing the separate can_modify_mm() step, and just doing checks on the individual vmas, when various operations are themselves iterating through the tree. This provides a nice speedup and restores performance parity with pre-mseal[3]. will-it-scale mmap1_process[1] -t 1 results: commit 3450fe2b574b4345e4296ccae395149e1a357fee: min:277605 max:277605 total:277605 min:281784 max:281784 total:281784 min:277238 max:277238 total:277238 min:281761 max:281761 total:281761 min:274279 max:274279 total:274279 min:254854 max:254854 total:254854 measurement min:269143 max:269143 total:269143 min:270454 max:270454 total:270454 min:243523 max:243523 total:243523 min:251148 max:251148 total:251148 min:209669 max:209669 total:209669 min:190426 max:190426 total:190426 min:231219 max:231219 total:231219 min:275364 max:275364 total:275364 min:266540 max:266540 total:266540 min:242572 max:242572 total:242572 min:284469 max:284469 total:284469 min:278882 max:278882 total:278882 min:283269 max:283269 total:283269 min:281204 max:281204 total:281204 After this patch set: min:280580 max:280580 total:280580 min:290514 max:290514 total:290514 min:291006 max:291006 total:291006 min:290352 max:290352 total:290352 min:294582 max:294582 total:294582 min:293075 max:293075 total:293075 measurement min:295613 max:295613 total:295613 min:294070 max:294070 total:294070 min:293193 max:293193 total:293193 min:291631 max:291631 total:291631 min:295278 max:295278 total:295278 min:293782 max:293782 total:293782 min:290361 max:290361 total:290361 min:294517 max:294517 total:294517 min:293750 max:293750 total:293750 min:293572 max:293572 total:293572 min:295239 max:295239 total:295239 min:292932 max:292932 total:292932 min:293319 max:293319 total:293319 min:294954 max:294954 total:294954 This was a Completely Unscientific test but seems to show there were around 5-10% gains on ops per second. Oliver performed his own tests and showed[3] a similar ~5% gain in them. [1]: mmap1_process does mmap and munmap in a loop. I didn't bother testing multithreading cases. [2]: https://lore.kernel.org/all/20240807124103.85644-1-mpe@ellerman.id.au/ [3]: https://lore.kernel.org/all/ZrMMJfe9aXSWxJz6@xsang-OptiPlex-9020/ Link: https://lore.kernel.org/all/202408041602.caa0372-oliver.sang@intel.com/ This patch (of 7): Move can_modify_vma to vma.h so it can be inlined properly (with the intent to remove can_modify_mm callsites). Link: https://lkml.kernel.org/r/20240817-mseal-depessimize-v3-1-d8d2e037df30@gmail.com Signed-off-by: Pedro Falcato Reviewed-by: Liam R. Howlett Reviewed-by: Lorenzo Stoakes Cc: Jeff Xu Cc: Kees Cook Cc: Linus Torvalds Cc: Michael Ellerman Cc: Pedro Falcato Cc: Shuah Khan Cc: Vlastimil Babka Signed-off-by: Andrew Morton --- mm/mseal.c | 17 ----------------- mm/vma.h | 28 ++++++++++++++++++++++++++++ 2 files changed, 28 insertions(+), 17 deletions(-) diff --git a/mm/mseal.c b/mm/mseal.c index 15bba28acc00..2170e2139ca0 100644 --- a/mm/mseal.c +++ b/mm/mseal.c @@ -16,28 +16,11 @@ #include #include "internal.h" -static inline bool vma_is_sealed(struct vm_area_struct *vma) -{ - return (vma->vm_flags & VM_SEALED); -} - static inline void set_vma_sealed(struct vm_area_struct *vma) { vm_flags_set(vma, VM_SEALED); } -/* - * check if a vma is sealed for modification. - * return true, if modification is allowed. - */ -static bool can_modify_vma(struct vm_area_struct *vma) -{ - if (unlikely(vma_is_sealed(vma))) - return false; - - return true; -} - static bool is_madv_discard(int behavior) { switch (behavior) { diff --git a/mm/vma.h b/mm/vma.h index 6efdf1768a0a..e979015cc7fc 100644 --- a/mm/vma.h +++ b/mm/vma.h @@ -361,4 +361,32 @@ struct vm_area_struct *vma_iter_prev_range(struct vma_iterator *vmi) return mas_prev_range(&vmi->mas, 0); } +#ifdef CONFIG_64BIT + +static inline bool vma_is_sealed(struct vm_area_struct *vma) +{ + return (vma->vm_flags & VM_SEALED); +} + +/* + * check if a vma is sealed for modification. + * return true, if modification is allowed. + */ +static inline bool can_modify_vma(struct vm_area_struct *vma) +{ + if (unlikely(vma_is_sealed(vma))) + return false; + + return true; +} + +#else + +static inline bool can_modify_vma(struct vm_area_struct *vma) +{ + return true; +} + +#endif + #endif /* __MM_VMA_H */ -- 2.25.1