The patch titled
Subject: mm/page-writeback.c: improve arithmetic divisions
has been added to the -mm tree. Its filename is
mm-page-writebackc-improve-arithmetic-divisions.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-page-writebackc-improve-arithmetic-divisions.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-page-writebackc-improve-arithmetic-divisions.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Wen Yang <wenyang@xxxxxxxxxxxxxxxxx>
Subject: mm/page-writeback.c: improve arithmetic divisions
Use div64_ul() instead of do_div() if the divisor is unsigned long, to
avoid truncation to 32-bit on 64-bit platforms.
Link: http://lkml.kernel.org/r/20200102081442.8273-4-wenyang@xxxxxxxxxxxxxxxxx
Signed-off-by: Wen Yang <wenyang@xxxxxxxxxxxxxxxxx>
Reviewed-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Qian Cai <cai@xxxxxx>
Cc: Tejun Heo <tj@xxxxxxxxxx>
Cc: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/page-writeback.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/mm/page-writeback.c~mm-page-writebackc-improve-arithmetic-divisions
+++ a/mm/page-writeback.c
@@ -1102,7 +1102,7 @@ static void wb_update_write_bandwidth(st
bw = written - min(written, wb->written_stamp);
bw *= HZ;
if (unlikely(elapsed > period)) {
- do_div(bw, elapsed);
+ bw = div64_ul(bw, elapsed);
avg = bw;
goto out;
}
_
Patches currently in -mm which might be from wenyang@xxxxxxxxxxxxxxxxx are
mm-page-writebackc-avoid-potential-division-by-zero-in-wb_min_max_ratio.patch
mm-page-writebackc-use-div64_ul-for-u64-by-unsigned-long-divide.patch
mm-page-writebackc-improve-arithmetic-divisions.patch
