Re: Move PinBuffer and UnpinBuffer to atomics

On Tue, Mar 29, 2016 at 10:43 PM, Andres Freund <andres(at)anarazel(dot)de> wrote:

> My gut feeling is that we should do both 1) and 2).
>
> Dilip, could you test performance of reducing ppc's spinlock to 1 byte?
> Cross-compiling suggest that doing so "just works". I.e. replace the
> #if defined(__ppc__) typedef from an int to a char.
>

I set that, but after that it hangs, even Initdb hangs..

int

│164 s_lock(volatile slock_t *lock, const char *file, int line)

│165 {

│166 SpinDelayStatus delayStatus;

│167

│168 init_spin_delay(&delayStatus, (Pointer)lock, file,
line);

│169

* │170 while (TAS_SPIN(lock))

*
* │171 {

*
* >│172 make_spin_delay(&delayStatus);

*
* │173 } *

│174

I did not try to find the reason, but just built in debug mode and found it
never come out of this loop.

I clean build multiple times but problem persist,

Does it have dependency of some other variable of defined under PPC in some
other place ? I don't know..

/* PowerPC */

*#if* defined(__ppc__) || defined(__powerpc__) || defined(__ppc64__) ||
defined(__powerpc64__)

*#define* HAS_TEST_AND_SET

*typedef* *unsigned* *int* slock_t; --> changed like this

*#define* TAS(lock) tas(lock)

--
Regards,
Dilip Kumar
EnterpriseDB: http://www.enterprisedb.com