Messages in this thread | | | Subject | Re: [PATCH v2] sched/pelt: Fix task util_est update filtering | From | Dietmar Eggemann <> | Date | Mon, 1 Mar 2021 17:34:09 +0100 |
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On 26/02/2021 09:41, Peter Zijlstra wrote: > On Thu, Feb 25, 2021 at 04:58:20PM +0000, Vincent Donnefort wrote: >> +#define UTIL_EST_MARGIN (SCHED_CAPACITY_SCALE / 100) >> + >> /* >> - * Check if a (signed) value is within a specified (unsigned) margin, >> + * Check if a (signed) value is within the (unsigned) util_est margin, >> * based on the observation that: >> * >> * abs(x) < y := (unsigned)(x + y - 1) < (2 * y - 1) >> * >> - * NOTE: this only works when value + maring < INT_MAX. >> + * NOTE: this only works when value + UTIL_EST_MARGIN < INT_MAX. >> */ >> -static inline bool within_margin(int value, int margin) >> +static inline bool util_est_within_margin(int value) >> { >> - return ((unsigned int)(value + margin - 1) < (2 * margin - 1)); >> + return ((unsigned int)(value + UTIL_EST_MARGIN - 1) < >> + (2 * UTIL_EST_MARGIN - 1)); >> } > >> - if (within_margin(last_ewma_diff, (SCHED_CAPACITY_SCALE / 100))) >> + if (util_est_within_margin(last_ewma_diff)) { > > What was the purpose of this change? What was a generic helper is now > super specific.
I guess because it was only ever used in util_est for last_ewma_diff.
It's now used for last_ewma_diff and last_enqueued_diff, still only for util_est though and both times with the same margin (SCHED_CAPACITY_SCALE / 100)).
Vincent D. should be back on Wed from hols.
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