Exploiting Dual Core's with Py_NewInterpreter's separated GIL ?

[Robin Becker]

I tried loading the module, but it seems already to be in the kernel.
Probably some sysctl stuff to do.

In fact the semaphore modules are built in now. I did some debugging and the
error happens in the code at SemSet.c line 25


for (i = 0; i < sets; i++) {
int id = semget(IPC_PRIVATE, MAX_SYSV_SET_SIZE, IPC_CREAT
| S_IREAD | S_IWRITE); //SEM_R | SEM_A);
if (id == -1) {

the first semget(i=0) succeeds and the second fails with an errno ENOSPC which
from the man page implies a resource issue of some kind.

[ENOSPC] Insufficiently many semaphores are available.
[ENOSPC] The kernel could not allocate a struct semid_ds.


I guess the freebsd limits must be different to the original development
environment.

 

[Andrew MacIntyre]

I tried loading the module, but it seems already to be in the kernel.
Probably some sysctl stuff to do.

In fact the semaphore modules are built in now. I did some debugging and the
error happens in the code at SemSet.c line 25


for (i = 0; i < sets; i++) {
int id = semget(IPC_PRIVATE, MAX_SYSV_SET_SIZE, IPC_CREAT
| S_IREAD | S_IWRITE); //SEM_R | SEM_A);
if (id == -1) {

the first semget(i=0) succeeds and the second fails with an errno ENOSPC which
from the man page implies a resource issue of some kind.

[ENOSPC] Insufficiently many semaphores are available.
[ENOSPC] The kernel could not allocate a struct semid_ds.


I guess the freebsd limits must be different to the original development
environment.

The number of semaphores is certainly tunable - the SYSV IPC KERNEL
PARAMETERS section in the file /usr/src/sys/conf/NOTES lists the SYSV
semaphore parameters that can be set in the kernel config.

--

 

[Robin Becker]

Andrew MacIntyre wrote:
.....

The number of semaphores is certainly tunable - the SYSV IPC KERNEL
PARAMETERS section in the file /usr/src/sys/conf/NOTES lists the SYSV
semaphore parameters that can be set in the kernel config.

yes those limits look pretty low. I think POSH grabs 60 the first time
and then fails the second as the limit appears to be 61. I wonder what
the actual cost is of having lots of semaphores.