On 9/19/19 3:05 PM, Cyrill Gorcunov wrote:
[..]
>> diff --git a/fs/select.c b/fs/select.c
>> index 12cdefd3be2d..2477c202631e 100644
>> --- a/fs/select.c
>> +++ b/fs/select.c
>> @@ -51,15 +51,14 @@
>>
>> static long __estimate_accuracy(ktime_t slack)
>> {
>> -int divfactor = 1000;
>> -
>>
On Mon, Sep 09, 2019 at 11:23:35AM +0100, Dmitry Safonov wrote:
> Shift on s64 is faster than division, use it instead.
>
> As the result of the patch there is a hardly user-visible effect:
> poll(), select(), etc syscalls will be a bit more precise on ~2.3%
> than before because 1000 != 1024 :)
>
On Mon, Sep 09, 2019 at 12:50:27PM +0100, Dmitry Safonov wrote:
> Hi Cyrill,
>
> On Mon, 9 Sep 2019 at 12:18, Cyrill Gorcunov wrote:
> > Compiler precompute constants so it doesn't do division here.
> > But I didn't read the series yet so I might be missing
> > something obvious.
>
> Heh, like a
Hi Cyrill,
On Mon, 9 Sep 2019 at 12:18, Cyrill Gorcunov wrote:
> Compiler precompute constants so it doesn't do division here.
> But I didn't read the series yet so I might be missing
> something obvious.
Heh, like a division is in ktime_divns()?
Thanks,
Dmitry
On Mon, Sep 09, 2019 at 11:23:35AM +0100, Dmitry Safonov wrote:
> Shift on s64 is faster than division, use it instead.
>
> As the result of the patch there is a hardly user-visible effect:
> poll(), select(), etc syscalls will be a bit more precise on ~2.3%
> than before because 1000 != 1024 :)
>
Shift on s64 is faster than division, use it instead.
As the result of the patch there is a hardly user-visible effect:
poll(), select(), etc syscalls will be a bit more precise on ~2.3%
than before because 1000 != 1024 :)
Signed-off-by: Dmitry Safonov
---
fs/select.c | 9 -
1 file chan
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