[PATCH] blk-iolatency: fix max_depth comparisons

[PATCH] blk-iolatency: fix max_depth comparisons

[Josef Bacik]

max_depth used to be a u64, but I changed it to a unsigned int but
didn't convert my comparisons over everywhere.  Fix by comparing to
INT_MAX instead of (u64)-1.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 block/blk-iolatency.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/block/blk-iolatency.c b/block/blk-iolatency.c
index a35a1f580337..5aabcb746f01 100644
--- a/block/blk-iolatency.c
+++ b/block/blk-iolatency.c
@@ -434,7 +434,7 @@ static void iolatency_record_time(struct iolatency_grp *iolat,
 	 * We don't want to count issue_as_root bio's in the cgroups latency
 	 * statistics as it could skew the numbers downwards.
 	 */
-	if (unlikely(issue_as_root && iolat->rq_depth.max_depth != (u64)-1)) {
+	if (unlikely(issue_as_root && iolat->rq_depth.max_depth != INT_MAX)) {
 		u64 sub = iolat->min_lat_nsec;
 		if (req_time < sub)
 			blkcg_add_delay(lat_to_blkg(iolat), now, sub - req_time);
@@ -817,7 +817,7 @@ static size_t iolatency_pd_stat(struct blkg_policy_data *pd, char *buf,
 	struct iolatency_grp *iolat = pd_to_lat(pd);
 	unsigned long long avg_lat = div64_u64(iolat->total_lat_avg, NSEC_PER_USEC);
 
-	if (iolat->rq_depth.max_depth == (u64)-1)
+	if (iolat->rq_depth.max_depth == INT_MAX)
 		return scnprintf(buf, size, " depth=max avg_lat=%llu",
 				 avg_lat);
 
-- 
2.14.3

Re: [PATCH] blk-iolatency: fix max_depth comparisons

[Jens Axboe]

On 7/11/18 7:30 AM, Josef Bacik wrote:
> max_depth used to be a u64, but I changed it to a unsigned int but
> didn't convert my comparisons over everywhere.  Fix by comparing to
> INT_MAX instead of (u64)-1.

Should that be UINT_MAX?

-- 
Jens Axboe

Re: [PATCH] blk-iolatency: fix max_depth comparisons

[Josef Bacik]

On Wed, Jul 11, 2018 at 08:22:28AM -0600, Jens Axboe wrote:
> On 7/11/18 7:30 AM, Josef Bacik wrote:
> > max_depth used to be a u64, but I changed it to a unsigned int but
> > didn't convert my comparisons over everywhere.  Fix by comparing to
> > INT_MAX instead of (u64)-1.
> 
> Should that be UINT_MAX?
> 

Hmm I suppose it should, though I'm really just using it to indicate that we're
unthrottled so it doesn't matter a whole lot.  Would you prefer I just switch it
all over to UINT_MAX?  Thanks,

Josef

Re: [PATCH] blk-iolatency: fix max_depth comparisons

[Jens Axboe]

On 7/11/18 8:28 AM, Josef Bacik wrote:
> On Wed, Jul 11, 2018 at 08:22:28AM -0600, Jens Axboe wrote:
>> On 7/11/18 7:30 AM, Josef Bacik wrote:
>>> max_depth used to be a u64, but I changed it to a unsigned int but
>>> didn't convert my comparisons over everywhere.  Fix by comparing to
>>> INT_MAX instead of (u64)-1.
>>
>> Should that be UINT_MAX?
>>
> 
> Hmm I suppose it should, though I'm really just using it to indicate that we're
> unthrottled so it doesn't matter a whole lot.  Would you prefer I just switch it
> all over to UINT_MAX?  Thanks,

Just seems cleaner, since it's the max of the type. Looks like you'd need
to change two spots that already set it to INT_MAX too.


-- 
Jens Axboe