Messages in this thread | | | Date | Mon, 1 Mar 2021 18:21:23 +0100 | From | Peter Zijlstra <> | Subject | Re: [PATCH v2] sched/pelt: Fix task util_est update filtering |
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On Mon, Mar 01, 2021 at 05:34:09PM +0100, Dietmar Eggemann wrote: > 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.
Fair enough; I've un-done it but kept the rest of the patch.
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