Messages in this thread Patch in this message | | | From | gao.yunxiao6@gmail ... | Subject | [PATCH] thermal: power_allocator: using round the division when re-divvying up power | Date | Mon, 15 Mar 2021 16:25:37 +0800 |
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From: "jeson.gao" <jeson.gao@unisoc.com>
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 it's max_power, it has the extra_power 759 actor1 received less than it's max_power, it require extra_actor_power 395 actor2 received less than it's 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 <jeson.gao@unisoc.com> --- drivers/thermal/gov_power_allocator.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/drivers/thermal/gov_power_allocator.c b/drivers/thermal/gov_power_allocator.c index 92acae53df49..2802a0e13c88 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, -- 2.28.0
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