Re: [PATCH] aarch64 suuport for libitm

[pinskia at gmail dot com]

> On Apr 2, 2014, at 7:37 AM, Richard Henderson <rth@redhat.com> wrote:
> 
>> On 04/01/2014 03:41 PM, Andrew Pinski wrote:
>>> On Tue, Apr 1, 2014 at 3:24 PM, Richard Henderson <rth@redhat.com> wrote:
>>> Comments?  If approved, should this go in for 4.9, or wait for stage1?
>>> Certainly it's self-contained...
>> 
>> On Cavium's thunder processor the cache line size is going to be
>> bigger than 64 bytes, what is your solution to improve performance on
>> target's like Thunder?
> 
> We can expand the number reasonably.  The only thing it controls is layout of
> some of the internal data structures to attempt to put different locks on
> different lines.
> 
> Is 128 big enough for Thunder?  Honestly, I may well not even have it right for
> the processor we have in house.  I didn't bother trying to track down docs to
> find out.

Yes 128 should be enough. 

Thanks,
Andrew

> 
>> Also I think the default page size for most Linux distros is going to
>> be 64k on aarch64 including Redhat Linux so it makes sense not to
>> define FIXED_PAGE_SIZE.
> 
> Heh.  It turns out these page size defines aren't used any more at all.  During
> one of the rewrites we must have delete the bits that used it.  I'll get rid of
> all of them so as to be less confusing.
> 
>> I will implement the ILP32 version of this patch once it goes in,
>> there needs a few changes in gtm_jmpbuf due to long and pointers being
>> 32bit but the assembly storing 64bits always.
> 
> I can minimize those changes now by using unsigned long long...
> 
> 
> r~
>