On Tue, 15 Apr 2025 17:02:32 +0800 alexjlzheng@gmail.com wrote:
From: Jinliang Zheng alexjlzheng@tencent.com
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.
Can you please tell us precisely where global_dirty_limits() prioritizes vm_dirty_bytes? I spent a while chasing code and didn't see how global_dirty_limits() gets to node_dirty_ok()(?).
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@tencent.com Reviewed-by: MengEn Sun mengensun@tencent.com Cc: stable@vger.kernel.org
Please, as always, provide a description of the userspace-visible effects of this bug?