Christophe Leroy writes:
> Le 21/08/2019 à 14:15, Segher Boessenkool a écrit :
>> On Wed, Aug 21, 2019 at 01:50:52PM +0200, Christophe Leroy wrote:
>>> Do you have any idea on how to avoid that bcl/mflr stuff ?
>>
>> Do a load from some fixed address? Maybe an absolute address, even?
>> lwz r3,
Le 21/08/2019 à 14:15, Segher Boessenkool a écrit :
On Wed, Aug 21, 2019 at 01:50:52PM +0200, Christophe Leroy wrote:
Do you have any idea on how to avoid that bcl/mflr stuff ?
Do a load from some fixed address? Maybe an absolute address, even?
lwz r3,-12344(0) or similar (that address is
Christophe Leroy writes:
> Le 21/08/2019 à 11:29, Santosh Sivaraj a écrit :
>> __get_datapage() is only a few instructions to retrieve the
>> address of the page where the kernel stores data to the VDSO.
>>
>> By inlining this function into its users, a bl/blr pair and
>> a mflr/mtlr pair is avoi
On Wed, Aug 21, 2019 at 01:50:52PM +0200, Christophe Leroy wrote:
> Le 21/08/2019 à 13:44, Segher Boessenkool a écrit :
> >Calls are cheap, in principle... It is the LR stuff that can make it
> >slower on some cores, and a lot of calling sequence stuff may have
> >considerable overhead of course.
Le 21/08/2019 à 13:44, Segher Boessenkool a écrit :
Hi!
On Wed, Aug 21, 2019 at 02:59:59PM +0530, Santosh Sivaraj wrote:
except for a couple of calls (1 or 2 nsec reduction), there are no
improvements in the call times. Or is 10 nsec the minimum granularity??
So I don't know if its even wor
Hi!
On Wed, Aug 21, 2019 at 02:59:59PM +0530, Santosh Sivaraj wrote:
> except for a couple of calls (1 or 2 nsec reduction), there are no
> improvements in the call times. Or is 10 nsec the minimum granularity??
>
> So I don't know if its even worth updating vdso64 except to keep vdso32 and
> vds
Christophe Leroy writes:
> Le 21/08/2019 à 11:29, Santosh Sivaraj a écrit :
>> __get_datapage() is only a few instructions to retrieve the
>> address of the page where the kernel stores data to the VDSO.
>>
>> By inlining this function into its users, a bl/blr pair and
>> a mflr/mtlr pair is avo
Le 21/08/2019 à 11:29, Santosh Sivaraj a écrit :
__get_datapage() is only a few instructions to retrieve the
address of the page where the kernel stores data to the VDSO.
By inlining this function into its users, a bl/blr pair and
a mflr/mtlr pair is avoided, plus a few reg moves.
clock-gett
__get_datapage() is only a few instructions to retrieve the
address of the page where the kernel stores data to the VDSO.
By inlining this function into its users, a bl/blr pair and
a mflr/mtlr pair is avoided, plus a few reg moves.
clock-gettime-monotonic: syscall: 514 nsec/call 396 nsec/call
c
