Commit f0a0cddd authored Sep 28, 2018 by Omar Sandoval Committed by Jens Axboe Sep 28, 2018

kyber: fix integer overflow of latency targets on 32-bit



NSEC_PER_SEC has type long, so 5 * NSEC_PER_SEC is calculated as a long.
However, 5 seconds is 5,000,000,000 nanoseconds, which overflows a
32-bit long. Make sure all of the targets are calculated as 64-bit
values.

Fixes: 6e25cb01 ("kyber: implement improved heuristics")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

parent e982c4d0

block/kyber-iosched.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -79,9 +79,9 @@ static const unsigned int kyber_depth[] = {
		* Default latency targets for each scheduling domain.
		*/
		static const u64 kyber_latency_targets[] = {
		[KYBER_READ] = 2 * NSEC_PER_MSEC,
		[KYBER_WRITE] = 10 * NSEC_PER_MSEC,
		[KYBER_DISCARD] = 5 * NSEC_PER_SEC,
		[KYBER_READ] = 2ULL * NSEC_PER_MSEC,
		[KYBER_WRITE] = 10ULL * NSEC_PER_MSEC,
		[KYBER_DISCARD] = 5ULL * NSEC_PER_SEC,
		};

		/*

Admin message