diff options
Diffstat (limited to 'block/blk-iocost.c')
| -rw-r--r-- | block/blk-iocost.c | 21 |
1 files changed, 15 insertions, 6 deletions
diff --git a/block/blk-iocost.c b/block/blk-iocost.c index ef287c33d6d9..e7d5aafa5e99 100644 --- a/block/blk-iocost.c +++ b/block/blk-iocost.c @@ -248,7 +248,9 @@ enum { /* 1/64k is granular enough and can easily be handled w/ u32 */ HWEIGHT_WHOLE = 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 @@ -271,6 +273,11 @@ enum { 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, @@ -288,9 +295,6 @@ enum { SURPLUS_SCALE_ABS = HWEIGHT_WHOLE / 50, /* + 2% */ SURPLUS_MIN_ADJ_DELTA = HWEIGHT_WHOLE / 33, /* 3% */ - /* 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 @@ -785,9 +789,14 @@ static void calc_lcoefs(u64 bps, u64 seqiops, u64 randiops, *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); |