From c09245f61c6ac4ef253a5fcf97e5bcfc0ce25fc7 Mon Sep 17 00:00:00 2001 From: Baolin Wang Date: Thu, 26 Nov 2020 16:16:13 +0800 Subject: blk-iocost: Move the usage ratio calculation to the correct place We only use the hweight based usage ratio to calculate the new hweight_inuse of the iocg to decide if this iocg can donate some surplus vtime. Thus move the usage ratio calculation to the correct place to avoid unnecessary calculation for some vtime shortage iocgs. Signed-off-by: Baolin Wang Acked-by: Tejun Heo Signed-off-by: Jens Axboe --- block/blk-iocost.c | 44 +++++++++++++++++++++++--------------------- 1 file changed, 23 insertions(+), 21 deletions(-) (limited to 'block') diff --git a/block/blk-iocost.c b/block/blk-iocost.c index ec4865206353..09f22f9a6ba4 100644 --- a/block/blk-iocost.c +++ b/block/blk-iocost.c @@ -2168,8 +2168,8 @@ static void ioc_timer_fn(struct timer_list *timer) /* calc usage and see whether some weights need to be moved around */ list_for_each_entry(iocg, &ioc->active_iocgs, active_list) { - u64 vdone, vtime, usage_us, usage_dur; - u32 usage, hw_active, hw_inuse; + u64 vdone, vtime, usage_us; + u32 hw_active, hw_inuse; /* * Collect unused and wind vtime closer to vnow to prevent @@ -2200,30 +2200,32 @@ static void ioc_timer_fn(struct timer_list *timer) usage_us = iocg->usage_delta_us; usage_us_sum += usage_us; - if (vdone != vtime) { - u64 inflight_us = DIV64_U64_ROUND_UP( - cost_to_abs_cost(vtime - vdone, hw_inuse), - ioc->vtime_base_rate); - usage_us = max(usage_us, inflight_us); - } - - /* convert to hweight based usage ratio */ - if (time_after64(iocg->activated_at, ioc->period_at)) - usage_dur = max_t(u64, now.now - iocg->activated_at, 1); - else - usage_dur = max_t(u64, now.now - ioc->period_at, 1); - - usage = clamp_t(u32, - DIV64_U64_ROUND_UP(usage_us * WEIGHT_ONE, - usage_dur), - 1, WEIGHT_ONE); - /* see whether there's surplus vtime */ WARN_ON_ONCE(!list_empty(&iocg->surplus_list)); if (hw_inuse < hw_active || (!waitqueue_active(&iocg->waitq) && time_before64(vtime, now.vnow - ioc->margins.low))) { - u32 hwa, old_hwi, hwm, new_hwi; + u32 hwa, old_hwi, hwm, new_hwi, usage; + u64 usage_dur; + + if (vdone != vtime) { + u64 inflight_us = DIV64_U64_ROUND_UP( + cost_to_abs_cost(vtime - vdone, hw_inuse), + ioc->vtime_base_rate); + + usage_us = max(usage_us, inflight_us); + } + + /* convert to hweight based usage ratio */ + if (time_after64(iocg->activated_at, ioc->period_at)) + usage_dur = max_t(u64, now.now - iocg->activated_at, 1); + else + usage_dur = max_t(u64, now.now - ioc->period_at, 1); + + usage = clamp_t(u32, + DIV64_U64_ROUND_UP(usage_us * WEIGHT_ONE, + usage_dur), + 1, WEIGHT_ONE); /* * Already donating or accumulated enough to start. -- cgit v1.2.3