Re: 128bit compare and swap

[James Peach <jp...@apache.org>]

On Mar 19, 2013, at 4:29 PM, Brian Geffon <br...@gmail.com> wrote:

> Ok, I'll get both of these committed.

this breaks valgrind :(

> 
> Brian
> 
> On Tue, Mar 19, 2013 at 4:18 PM, John Plevyak <jp...@acm.org> wrote:
> 
>> Definitely should do that as well.
>> 
>> john
>> 
>> On Tue, Mar 19, 2013 at 4:04 PM, Brian Geffon <br...@gmail.com>
>> wrote:
>> 
>>> Thanks John!
>>> 
>>> Someone else mentioned that we might need to force the head_p to be 16
>> byte
>>> aligned, what are your thoughts?
>>> 
>>> -  } head_p;
>>> +  } __attribute__ ((aligned (16))) head_p;
>>> 
>>> 
>>> Thanks.
>>> Brian
>>> 
>>> On Tue, Mar 19, 2013 at 3:47 PM, John Plevyak <jp...@acm.org> wrote:
>>> 
>>>> I believe the problem is with INK_QUEUE_LD which is not atomic:
>>>> 
>>>> diff --git a/lib/ts/ink_queue.h b/lib/ts/ink_queue.h
>>>> index 6ac9945..20fbf9a 100644
>>>> --- a/lib/ts/ink_queue.h
>>>> +++ b/lib/ts/ink_queue.h
>>>> @@ -72,7 +72,7 @@ extern "C"
>>>> #endif
>>>> 
>>>> #if TS_HAS_128BIT_CAS
>>>> -#define INK_QUEUE_LD(dst,src) *((__int128_t*)&(dst)) =
>>>> *((__int128_t*)&(src))
>>>> +#define INK_QUEUE_LD(dst,src) *(__int128_t*)&(dst) =
>>>> __sync_fetch_and_add((__int128_t*)&(src), 0)
>>>> #else
>>>> #define INK_QUEUE_LD(dst,src) INK_QUEUE_LD64(dst,src)
>>>> #endif
>>>> 
>>>> This fixes the problem.
>>>> 
>>>> On Mon, Mar 18, 2013 at 9:31 PM, Brian Geffon <br...@apache.org>
>> wrote:
>>>> 
>>>>> Hey, I'm looking into the failing freelist tests using the precise64
>>>>> vagrant box. If I can't figure it out tonight I'll just disable the
>>> check
>>>>> in configure.ac to get things stable again for the time being. If
>>> anyone
>>>>> else has some time to help out with this, I'd really appreciate it.
>>>>> 
>>>>> Brian
>>>>> 
>>>>> On Mon, Mar 18, 2013 at 9:49 AM, James Peach <ja...@me.com>
>>> wrote:
>>>>> 
>>>>>> Hi Brian,
>>>>>> 
>>>>>> I finally fixed the autoconf tests for TS_HAS_128BIT_CAS.
>>> Unfortunately
>>>>>> test_freelist fails on all the platforms that I have access to. I'm
>>>>>> assuming that on your platforms it succeeds, so maybe there's
>>> something
>>>>>> about the version of gcc you are using that makes it work.
>>>>>> 
>>>>>> Since I don't really know which platforms this is working for, what
>>> do
>>>>> you
>>>>>> think about reverting this?
>>>>>> 
>>>>>> J
>>>>> 
>>>> 
>>> 
>> 

Re: 128bit compare and swap

[James Peach <jp...@apache.org>]

On Apr 15, 2013, at 9:42 AM, Leif Hedstrom <zw...@apache.org> wrote:

> On 4/15/13 10:33 AM, James Peach wrote:
>> On Mar 19, 2013, at 4:29 PM, Brian Geffon <br...@gmail.com> wrote:
>> 
>>> Ok, I'll get both of these committed.
>> this breaks valgrind :(
> 
> Theo pointed out this is related to running valgrind under VirtualBox. I confirmed, on my bare-metal Fedora Core box, Valgrind still works fine with current master.

Oh great!

J

Re: 128bit compare and swap

[Leif Hedstrom <zw...@apache.org>]

On 4/15/13 10:33 AM, James Peach wrote:
> On Mar 19, 2013, at 4:29 PM, Brian Geffon <br...@gmail.com> wrote:
>
>> Ok, I'll get both of these committed.
> this breaks valgrind :(

Theo pointed out this is related to running valgrind under VirtualBox. I 
confirmed, on my bare-metal Fedora Core box, Valgrind still works fine with 
current master.

-- Leif