Yafang Shao wrote:
> >> I have also verified your test code on my machine, but can not find
> >> this message.
> >>
> >
> > Not always printed. It is timing dependent.
> >
>
> I will try and analysis why this happen.
>
I see.
Here is dump of variables. Always mostly 0 when this happens.
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -434,7 +434,8 @@ static void domain_dirty_limits(struct dirty_throttle_control *dtc)
bg_thresh = (bg_ratio * available_memory) / PAGE_SIZE;
if (unlikely(bg_thresh >= thresh)) {
- pr_warn("vm direct limit must be set greater than background limit.\n");
+ pr_warn("vm direct limit must be set greater than background limit. bg_thresh=%lu thresh=%lu bg_bytes=%lu bytes=%lu bg_ratio=%lu ratio=%lu gdtc=%p gdtc->vail=%lu vm_dirty_bytes=%lu dirty_background_bytes=%lu\n",
+ bg_thresh, thresh, bg_bytes, bytes, bg_ratio, ratio, gdtc, gdtc ? gdtc->avail : 0UL, vm_dirty_bytes, dirty_background_bytes);
bg_thresh = thresh / 2;
}
[ 259.641324] vm direct limit must be set greater than background limit. bg_thresh=0 thresh=0 bg_bytes=0 bytes=0 bg_ratio=409 ratio=1228 gdtc= (null) gdtc->vail=0 vm_dirty_bytes=0 dirty_background_bytes=0
[ 317.798913] vm direct limit must be set greater than background limit. bg_thresh=0 thresh=0 bg_bytes=0 bytes=0 bg_ratio=409 ratio=1228 gdtc= (null) gdtc->vail=0 vm_dirty_bytes=0 dirty_background_bytes=0
[ 317.798935] vm direct limit must be set greater than background limit. bg_thresh=0 thresh=0 bg_bytes=0 bytes=0 bg_ratio=409 ratio=1228 gdtc= (null) gdtc->vail=0 vm_dirty_bytes=0 dirty_background_bytes=0
[ 317.976210] vm direct limit must be set greater than background limit. bg_thresh=0 thresh=0 bg_bytes=0 bytes=0 bg_ratio=409 ratio=1228 gdtc= (null) gdtc->vail=0 vm_dirty_bytes=0 dirty_background_bytes=0
[ 417.781194] vm direct limit must be set greater than background limit. bg_thresh=0 thresh=0 bg_bytes=0 bytes=0 bg_ratio=409 ratio=1228 gdtc= (null) gdtc->vail=0 vm_dirty_bytes=0 dirty_background_bytes=0
[ 466.322615] vm direct limit must be set greater than background limit. bg_thresh=0 thresh=0 bg_bytes=0 bytes=0 bg_ratio=409 ratio=1228 gdtc= (null) gdtc->vail=0 vm_dirty_bytes=0 dirty_background_bytes=0
[ 466.322618] vm direct limit must be set greater than background limit. bg_thresh=0 thresh=0 bg_bytes=0 bytes=0 bg_ratio=409 ratio=1228 gdtc= (null) gdtc->vail=0 vm_dirty_bytes=0 dirty_background_bytes=0
[ 466.497893] vm direct limit must be set greater than background limit. bg_thresh=0 thresh=0 bg_bytes=0 bytes=0 bg_ratio=409 ratio=1228 gdtc= (null) gdtc->vail=0 vm_dirty_bytes=0 dirty_background_bytes=0
[ 466.504687] vm direct limit must be set greater than background limit. bg_thresh=0 thresh=0 bg_bytes=0 bytes=0 bg_ratio=409 ratio=1228 gdtc= (null) gdtc->vail=0 vm_dirty_bytes=0 dirty_background_bytes=0
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@xxxxxxxxx. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
