Re: linux-next: build warning after merge of the block tree

From: Omar Sandoval
Date: Fri Sep 28 2018 - 02:43:25 EST


On Fri, Sep 28, 2018 at 11:11:24AM +1000, Stephen Rothwell wrote:
> Hi Jens,
>
> After merging the block tree, today's linux-next build (arm
> multi_v7_defconfig) produced this warning:
>
> block/kyber-iosched.c:84:22: warning: integer overflow in expression of type 'long int' results in '705032704' [-Woverflow]
> [KYBER_DISCARD] = 5 * NSEC_PER_SEC,
> ^
>
> Introduced by commit
>
> 6e25cb01ea20 ("kyber: implement improved heuristics")

Ugh, thanks for the report. This should fix it:

diff --git a/block/kyber-iosched.c b/block/kyber-iosched.c
index 2b62e362fb36..eccac01a10b6 100644
--- a/block/kyber-iosched.c
+++ b/block/kyber-iosched.c
@@ -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,
};

/*

Jens, do you mind folding that in, or should I send it separately?