site_archiver@lists.apple.com Delivered-To: darwin-dev@lists.apple.com -- Terry _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev@lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.appl... On Jan 29, 2009, at 10:57 AM, Rohitash Panda <rohitash.panda@oracle.com> wrote: Folks, Is there a sysctl parameter that can be changed , to set the limit on the number of operations in a single semop() call ? Is it configurable ? No. The value is hard-coded to MAX_SOPS, which is currently defined in sem.h as 5; also note the comment in that file which indicates the value is informational and subject to change in the future. If you need more than that, you will need to make multiple calls. Note that even if you limit yourself, the operations you group will only be individually atomic, not group idempotent (POSIX does not guarantee it), so there's no benefit other than reduced number of system calls to grouping a larger number of them together. Given that semaphore operations are themselves pretty heavyweight, the amortized overhead costs of extra calls for a larger number of them is proportionally small. This email sent to site_archiver@lists.apple.com