Commit 0a5d1a7f authored by Wen Yang's avatar Wen Yang Committed by Linus Torvalds

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@linux.alibaba.comSigned-off-by: default avatarWen Yang <wenyang@linux.alibaba.com>
Reviewed-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Cc: Qian Cai <cai@lca.pw>
Cc: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent d3ac946e
......@@ -1102,7 +1102,7 @@ static void wb_update_write_bandwidth(struct bdi_writeback *wb,
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;
}
......
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