From: jeson.gao Date: Mon, 15 Mar 2021 08:25:37 +0000 (+0800) Subject: thermal/core/power_allocator: Using round the division when re-divvying up power X-Git-Tag: accepted/tizen/unified/20230118.172025~7286^2~41 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=6e3e14c9385c3cfb35f9da4f495acdd21f9bc25b;p=platform%2Fkernel%2Flinux-rpi.git thermal/core/power_allocator: Using round the division when re-divvying up power The division is used directly in re-divvying up power, the decimal part will be discarded, devices will get less than the extra_actor_power - 1. if using round the division to make the calculation more accurate. For example: actor0 received more than its max_power, it has the extra_power 759 actor1 received less than its max_power, it require extra_actor_power 395 actor2 received less than its max_power, it require extra_actor_power 365 actor1 and actor2 require the total capped_extra_power 760 using division in re-divvying up power actor1 would actually get the extra_actor_power 394 actor2 would actually get the extra_actor_power 364 if using round the division in re-divvying up power actor1 would actually get the extra_actor_power 394 actor2 would actually get the extra_actor_power 365 Signed-off-by: Jeson Gao Reviewed-by: Lukasz Luba Signed-off-by: Daniel Lezcano Link: https://lore.kernel.org/r/1615796737-4688-1-git-send-email-gao.yunxiao6@gmail.com --- diff --git a/drivers/thermal/gov_power_allocator.c b/drivers/thermal/gov_power_allocator.c index 92acae53..2802a0e 100644 --- a/drivers/thermal/gov_power_allocator.c +++ b/drivers/thermal/gov_power_allocator.c @@ -374,9 +374,11 @@ static void divvy_up_power(u32 *req_power, u32 *max_power, int num_actors, */ extra_power = min(extra_power, capped_extra_power); if (capped_extra_power > 0) - for (i = 0; i < num_actors; i++) - granted_power[i] += (extra_actor_power[i] * - extra_power) / capped_extra_power; + for (i = 0; i < num_actors; i++) { + u64 extra_range = (u64)extra_actor_power[i] * extra_power; + granted_power[i] += DIV_ROUND_CLOSEST_ULL(extra_range, + capped_extra_power); + } } static int allocate_power(struct thermal_zone_device *tz,