From: Jinliang Zheng <alexjlzheng@xxxxxxxxxxx>
In the dirty_ratio_handler() function, vm_dirty_bytes must be set to
zero before calling writeback_set_ratelimit(), as global_dirty_limits()
always prioritizes the value of vm_dirty_bytes.
That causes ratelimit_pages to still use the value calculated based on
vm_dirty_bytes, which is wrong now.
Fixes: 9d823e8f6b1b ("writeback: per task dirty rate limit")
Signed-off-by: Jinliang Zheng <alexjlzheng@xxxxxxxxxxx>
Reviewed-by: MengEn Sun <mengensun@xxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
---
Changelog:
v2: A more detailed description
v1: https://lore.kernel.org/linux-fsdevel/20250415083542.6946-1-alexjlzheng@xxxxxxxxxxx/T/#u
---
mm/page-writeback.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index c81624bc3969..20e1d76f1eba 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -520,8 +520,8 @@ static int dirty_ratio_handler(const struct ctl_table *table, int write, void *b
ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
if (ret == 0 && write && vm_dirty_ratio != old_ratio) {
- writeback_set_ratelimit();
vm_dirty_bytes = 0;
+ writeback_set_ratelimit();
}
return ret;
}
--
2.49.0
