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mm: multi-gen LRU: add helpers in page table walks

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Add helpers to page table walking code:
 - Clarifies intent via name "should_walk_mmu" and "should_clear_pmd_young"
 - Avoids repeating same logic in two places

Link: https://lkml.kernel.org/r/20230522112058.2965866-3-talumbau@google.com
Signed-off-by: T.J. Alumbaugh <talumbau@google.com>
Reviewed-by: Yuanchu Xie <yuanchu@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
T.J. Alumbaugh 2023-05-22 11:20:57 +00:00 committed by Andrew Morton
parent 5c7e7a0d79
commit bd02df412c
1 changed files with 15 additions and 5 deletions
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20
mm/vmscan.c
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@ -3234,6 +3234,16 @@ DEFINE_STATIC_KEY_ARRAY_FALSE(lru_gen_caps, NR_LRU_GEN_CAPS);
#define get_cap(cap) static_branch_unlikely(&lru_gen_caps[cap]) #define get_cap(cap) static_branch_unlikely(&lru_gen_caps[cap])
#endif #endif
static bool should_walk_mmu(void)
{
return arch_has_hw_pte_young() && get_cap(LRU_GEN_MM_WALK);
}
static bool should_clear_pmd_young(void)
{
return arch_has_hw_nonleaf_pmd_young() && get_cap(LRU_GEN_NONLEAF_YOUNG);
}
/****************************************************************************** /******************************************************************************
* shorthand helpers * shorthand helpers
******************************************************************************/ ******************************************************************************/
@ -4098,7 +4108,7 @@ static void walk_pmd_range_locked(pud_t *pud, unsigned long addr, struct vm_area
goto next; goto next;
if (!pmd_trans_huge(pmd[i])) { if (!pmd_trans_huge(pmd[i])) {
if (arch_has_hw_nonleaf_pmd_young() && get_cap(LRU_GEN_NONLEAF_YOUNG)) if (should_clear_pmd_young())
pmdp_test_and_clear_young(vma, addr, pmd + i); pmdp_test_and_clear_young(vma, addr, pmd + i);
goto next; goto next;
} }
@ -4191,7 +4201,7 @@ restart:
#endif #endif
walk->mm_stats[MM_NONLEAF_TOTAL]++; walk->mm_stats[MM_NONLEAF_TOTAL]++;
if (arch_has_hw_nonleaf_pmd_young() && get_cap(LRU_GEN_NONLEAF_YOUNG)) { if (should_clear_pmd_young()) {
if (!pmd_young(val)) if (!pmd_young(val))
continue; continue;
@ -4493,7 +4503,7 @@ static bool try_to_inc_max_seq(struct lruvec *lruvec, unsigned long max_seq,
* handful of PTEs. Spreading the work out over a period of time usually * handful of PTEs. Spreading the work out over a period of time usually
* is less efficient, but it avoids bursty page faults. * is less efficient, but it avoids bursty page faults.
*/ */
if (!arch_has_hw_pte_young() || !get_cap(LRU_GEN_MM_WALK)) { if (!should_walk_mmu()) {
success = iterate_mm_list_nowalk(lruvec, max_seq); success = iterate_mm_list_nowalk(lruvec, max_seq);
goto done; goto done;
} }
@ -5730,10 +5740,10 @@ static ssize_t enabled_show(struct kobject *kobj, struct kobj_attribute *attr, c
if (get_cap(LRU_GEN_CORE)) if (get_cap(LRU_GEN_CORE))
caps |= BIT(LRU_GEN_CORE); caps |= BIT(LRU_GEN_CORE);
if (arch_has_hw_pte_young() && get_cap(LRU_GEN_MM_WALK)) if (should_walk_mmu())
caps |= BIT(LRU_GEN_MM_WALK); caps |= BIT(LRU_GEN_MM_WALK);
if (arch_has_hw_nonleaf_pmd_young() && get_cap(LRU_GEN_NONLEAF_YOUNG)) if (should_clear_pmd_young())
caps |= BIT(LRU_GEN_NONLEAF_YOUNG); caps |= BIT(LRU_GEN_NONLEAF_YOUNG);
return sysfs_emit(buf, "0x%04x\n", caps); return sysfs_emit(buf, "0x%04x\n", caps);