On Thu, May 07, 2015 at 12:13:22AM -0700, Tahsin Erdogan wrote:
> > Perhaps we need to CC stable (3.19) too..?
> >
>
> Hi Greg,
> Could you please push this patch to 3.19 ?
>
> commit sha: e8a4a2696fecb398b0288c43c0e0dbb91e265bb2
It's not even in a released version from Linus, so I can't add it
On Thu, May 07, 2015 at 12:13:22AM -0700, Tahsin Erdogan wrote:
Perhaps we need to CC stable (3.19) too..?
Hi Greg,
Could you please push this patch to 3.19 ?
commit sha: e8a4a2696fecb398b0288c43c0e0dbb91e265bb2
It's not even in a released version from Linus, so I can't add it to
> Perhaps we need to CC stable (3.19) too..?
>
Hi Greg,
Could you please push this patch to 3.19 ?
commit sha: e8a4a2696fecb398b0288c43c0e0dbb91e265bb2
thanks
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More
Perhaps we need to CC stable (3.19) too..?
Hi Greg,
Could you please push this patch to 3.19 ?
commit sha: e8a4a2696fecb398b0288c43c0e0dbb91e265bb2
thanks
--
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to majord...@vger.kernel.org
More
On 05/05/2015 09:45 AM, Tahsin Erdogan wrote:
A spinlock is regarded as contended when there is at least one waiter.
Currently, the code that checks whether there are any waiters rely on
tail value being greater than head. However, this is not true if tail
reaches the max value and wraps back to
On 05/05/2015 09:45 AM, Tahsin Erdogan wrote:
A spinlock is regarded as contended when there is at least one waiter.
Currently, the code that checks whether there are any waiters rely on
tail value being greater than head. However, this is not true if tail
reaches the max value and wraps back to
On Tue, May 05, 2015 at 07:10:19AM -0700, Tahsin Erdogan wrote:
> The conversion to signed happens with types shorter than int
> (__ticket_t is either u8 or u16).
Argh yes, I see.
(ISO C99) 6.3.1.1 rule 2 states that: "If an int can represent all values
of the original type, the value is
On 05/05/2015 07:33 PM, Tahsin Erdogan wrote:
The conversion to signed happens with types shorter than int (__ticket_t
is either u8 or u16).
By changing Raghavendra's program to use unsigned short int, you can see
the problem:
#include
#define LOCK_INC 2
int main()
{
On 05/05/2015 11:25 AM, Raghavendra K T wrote:
On 05/05/2015 07:33 PM, Tahsin Erdogan wrote:
The conversion to signed happens with types shorter than int (__ticket_t
is either u8 or u16).
By changing Raghavendra's program to use unsigned short int, you can see
the problem:
On 05/05/2015 09:02 PM, Waiman Long wrote:
On 05/05/2015 11:25 AM, Raghavendra K T wrote:
On 05/05/2015 07:33 PM, Tahsin Erdogan wrote:
The conversion to signed happens with types shorter than int (__ticket_t
is either u8 or u16).
By changing Raghavendra's program to use unsigned short int,
The conversion to signed happens with types shorter than int
(__ticket_t is either u8 or u16).
By changing Raghavendra's program to use unsigned short int, you can
see the problem:
#include
#define LOCK_INC 2
int main()
{
unsigned short int head = 32700, tail=2;
//#define LOCK_INC ((unsigned int)2) // case 1
This works because it is casting to unsigned int. If you change it to
unsigned short int, it becomes consistent with case 2.
On Tue, May 5, 2015 at 8:25 AM, Raghavendra K T
wrote:
> On 05/05/2015 07:33 PM, Tahsin Erdogan wrote:
>>
>> The conversion
On Tue, May 05, 2015 at 04:08:22PM +0530, Raghavendra K T wrote:
>
> #include
>
> #define LOCK_INC 2
Note that to be completely identical to the kernel code you should've
written:
#define LOCK_INC((unsigned int)2)
as per:
#define TICKET_LOCK_INC
On 05/05/2015 02:47 PM, Peter Zijlstra wrote:
On Mon, May 04, 2015 at 09:15:31PM -0700, Tahsin Erdogan wrote:
A spinlock is regarded as contended when there is at least one waiter.
Currently, the code that checks whether there are any waiters rely on
tail value being greater than head. However,
On Mon, May 04, 2015 at 09:15:31PM -0700, Tahsin Erdogan wrote:
> A spinlock is regarded as contended when there is at least one waiter.
> Currently, the code that checks whether there are any waiters rely on
> tail value being greater than head. However, this is not true if tail
> reaches the max
The conversion to signed happens with types shorter than int
(__ticket_t is either u8 or u16).
By changing Raghavendra's program to use unsigned short int, you can
see the problem:
#include stdio.h
#define LOCK_INC 2
int main()
{
unsigned short int head = 32700,
On 05/05/2015 07:33 PM, Tahsin Erdogan wrote:
The conversion to signed happens with types shorter than int (__ticket_t
is either u8 or u16).
By changing Raghavendra's program to use unsigned short int, you can see
the problem:
#include stdio.h
#define LOCK_INC 2
int main()
{
//#define LOCK_INC ((unsigned int)2) // case 1
This works because it is casting to unsigned int. If you change it to
unsigned short int, it becomes consistent with case 2.
On Tue, May 5, 2015 at 8:25 AM, Raghavendra K T
raghavendra...@linux.vnet.ibm.com wrote:
On 05/05/2015 07:33 PM, Tahsin
On 05/05/2015 11:25 AM, Raghavendra K T wrote:
On 05/05/2015 07:33 PM, Tahsin Erdogan wrote:
The conversion to signed happens with types shorter than int (__ticket_t
is either u8 or u16).
By changing Raghavendra's program to use unsigned short int, you can see
the problem:
On 05/05/2015 09:02 PM, Waiman Long wrote:
On 05/05/2015 11:25 AM, Raghavendra K T wrote:
On 05/05/2015 07:33 PM, Tahsin Erdogan wrote:
The conversion to signed happens with types shorter than int (__ticket_t
is either u8 or u16).
By changing Raghavendra's program to use unsigned short int,
On Tue, May 05, 2015 at 07:10:19AM -0700, Tahsin Erdogan wrote:
The conversion to signed happens with types shorter than int
(__ticket_t is either u8 or u16).
Argh yes, I see.
(ISO C99) 6.3.1.1 rule 2 states that: If an int can represent all values
of the original type, the value is converted
On Mon, May 04, 2015 at 09:15:31PM -0700, Tahsin Erdogan wrote:
A spinlock is regarded as contended when there is at least one waiter.
Currently, the code that checks whether there are any waiters rely on
tail value being greater than head. However, this is not true if tail
reaches the max
On 05/05/2015 02:47 PM, Peter Zijlstra wrote:
On Mon, May 04, 2015 at 09:15:31PM -0700, Tahsin Erdogan wrote:
A spinlock is regarded as contended when there is at least one waiter.
Currently, the code that checks whether there are any waiters rely on
tail value being greater than head. However,
On Tue, May 05, 2015 at 04:08:22PM +0530, Raghavendra K T wrote:
#include stdio.h
#define LOCK_INC 2
Note that to be completely identical to the kernel code you should've
written:
#define LOCK_INC((unsigned int)2)
as per:
#define TICKET_LOCK_INC
A spinlock is regarded as contended when there is at least one waiter.
Currently, the code that checks whether there are any waiters rely on
tail value being greater than head. However, this is not true if tail
reaches the max value and wraps back to zero, so arch_spin_is_contended()
incorrectly
A spinlock is regarded as contended when there is at least one waiter.
Currently, the code that checks whether there are any waiters rely on
tail value being greater than head. However, this is not true if tail
reaches the max value and wraps back to zero, so arch_spin_is_contended()
incorrectly
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