Replace the if/else chain of sysfs_streq() calls in defrag_store() with sysfs_match_string() and a defrag_mode_strings[] table. Introduce enum defrag_mode and defrag_flags[] array mapping each mode to its corresponding transparent_hugepage_flag. The store function now loops over defrag_flags[], setting the bit for the selected mode and clearing the others. When mode is DEFRAG_NEVER (index 4), no index in the 4-element defrag_flags[] matches, so all flags are cleared. Note that the enum ordering (always, defer, defer+madvise, madvise, never) differs from the original if/else chain order in defrag_store() (always, defer+madvise, defer, madvise, never). This is intentional to match the display order used by defrag_show(). This is a follow-up cleanup to commit 522dfb4ba71f ("mm: huge_memory: refactor anon_enabled_store() with change_anon_orders()") which applied the same sysfs_match_string() pattern to anon_enabled_store(). Acked-by: David Hildenbrand (Arm) Tested-by: Lance Yang Reviewed-by: Lance Yang Reviewed-by: Barry Song Signed-off-by: Breno Leitao --- mm/huge_memory.c | 60 ++++++++++++++++++++++++++++++++------------------------ 1 file changed, 34 insertions(+), 26 deletions(-) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 970e077019b75..76f2d32428c7f 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -429,6 +429,29 @@ ssize_t single_hugepage_flag_store(struct kobject *kobj, return count; } +enum defrag_mode { + DEFRAG_ALWAYS = 0, + DEFRAG_DEFER, + DEFRAG_DEFER_MADVISE, + DEFRAG_MADVISE, + DEFRAG_NEVER, +}; + +static const char * const defrag_mode_strings[] = { + [DEFRAG_ALWAYS] = "always", + [DEFRAG_DEFER] = "defer", + [DEFRAG_DEFER_MADVISE] = "defer+madvise", + [DEFRAG_MADVISE] = "madvise", + [DEFRAG_NEVER] = "never", +}; + +static const enum transparent_hugepage_flag defrag_flags[] = { + [DEFRAG_ALWAYS] = TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, + [DEFRAG_DEFER] = TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG, + [DEFRAG_DEFER_MADVISE] = TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, + [DEFRAG_MADVISE] = TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, +}; + static ssize_t defrag_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) { @@ -456,34 +479,19 @@ static ssize_t defrag_store(struct kobject *kobj, struct kobj_attribute *attr, const char *buf, size_t count) { - if (sysfs_streq(buf, "always")) { - clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG, &transparent_hugepage_flags); - clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, &transparent_hugepage_flags); - clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, &transparent_hugepage_flags); - set_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, &transparent_hugepage_flags); - } else if (sysfs_streq(buf, "defer+madvise")) { - clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, &transparent_hugepage_flags); - clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG, &transparent_hugepage_flags); - clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, &transparent_hugepage_flags); - set_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, &transparent_hugepage_flags); - } else if (sysfs_streq(buf, "defer")) { - clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, &transparent_hugepage_flags); - clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, &transparent_hugepage_flags); - clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, &transparent_hugepage_flags); - set_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG, &transparent_hugepage_flags); - } else if (sysfs_streq(buf, "madvise")) { - clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, &transparent_hugepage_flags); - clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG, &transparent_hugepage_flags); - clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, &transparent_hugepage_flags); - set_bit(TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, &transparent_hugepage_flags); - } else if (sysfs_streq(buf, "never")) { - clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, &transparent_hugepage_flags); - clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG, &transparent_hugepage_flags); - clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, &transparent_hugepage_flags); - clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, &transparent_hugepage_flags); - } else + int mode, m; + + mode = sysfs_match_string(defrag_mode_strings, buf); + if (mode < 0) return -EINVAL; + for (m = 0; m < ARRAY_SIZE(defrag_flags); m++) { + if (m == mode) + set_bit(defrag_flags[m], &transparent_hugepage_flags); + else + clear_bit(defrag_flags[m], &transparent_hugepage_flags); + } + return count; } static struct kobj_attribute defrag_attr = __ATTR_RW(defrag); -- 2.52.0