/* 1/64k is granular enough and can easily be handled w/ u32 */
WEIGHT_ONE = 1 << 16,
+};
+enum {
/*
* As vtime is used to calculate the cost of each IO, it needs to
* be fairly high precision. For example, it should be able to
VRATE_MIN = VTIME_PER_USEC * VRATE_MIN_PPM / MILLION,
VRATE_CLAMP_ADJ_PCT = 4,
+ /* switch iff the conditions are met for longer than this */
+ AUTOP_CYCLE_NSEC = 10LLU * NSEC_PER_SEC,
+};
+
+enum {
/* if IOs end up waiting for requests, issue less */
RQ_WAIT_BUSY_PCT = 5,
/* don't let cmds which take a very long time pin lagging for too long */
MAX_LAGGING_PERIODS = 10,
- /* switch iff the conditions are met for longer than this */
- AUTOP_CYCLE_NSEC = 10LLU * NSEC_PER_SEC,
-
/*
* Count IO size in 4k pages. The 12bit shift helps keeping
* size-proportional components of cost calculation in closer
*page = *seqio = *randio = 0;
- if (bps)
- *page = DIV64_U64_ROUND_UP(VTIME_PER_SEC,
- DIV_ROUND_UP_ULL(bps, IOC_PAGE_SIZE));
+ if (bps) {
+ u64 bps_pages = DIV_ROUND_UP_ULL(bps, IOC_PAGE_SIZE);
+
+ if (bps_pages)
+ *page = DIV64_U64_ROUND_UP(VTIME_PER_SEC, bps_pages);
+ else
+ *page = 1;
+ }
if (seqiops) {
v = DIV64_U64_ROUND_UP(VTIME_PER_SEC, seqiops);