MLock errors on Intel 8-core systems
MLock errors on Intel 8-core systems
- Subject: MLock errors on Intel 8-core systems
- From: Tony Scaminaci <email@hidden>
- Date: Sat, 4 Oct 2008 16:30:40 -0700 (PDT)
Hi,
I'm the author of memtestosx and I recently started receiving reports of mlock failures in single-user mode. Specifically, I've had 3 users report that mlock fails to lock more than 4GB of memory in a single process. I see in the mlock man pages that this indeed appears to be the limit and that a few new error codes were added since the last time I did any work with mlock. However, the strange thing is that this error is only appearing on 8-core Intel machines. I've received no reports of problems from any other users. Here's the error returned by memtest which is mlock error code EAGAIN:
Mac OS X 10.5.4 (9E25) running in single user mode
Memory Page Size: 4096
System has 8 Intel core(s) with SSE
Requested memory: 9756MB (10230386688 bytes)
Available memory: 9756MB (10230386688 bytes)
NOTE: Memory request is too large, reducing
to acceptable value...
Allocated memory: 9483MB (9943935808 bytes) at local address 0x0000000101000000
Attempting memory lock... ERROR: System or per-process limit exceeded - reducing and trying again...
Users are reporting that reducing the requested test allocation to 4GB rather than all installed ram allows mlock to succeed on the 8-core systems.
So this raises a few questions:
1. Why is this error only occuring on 8-core systems?
2. Why is there a lock limit of 4GB now when there hasn't been in the past? I've had many users with 16GB of installed ram who never saw this error on other platforms. Or maybe the limit has always been there and is only manifesting itself on the 8-core machines?
3. Is locking memory for mass testing even necessary in single-user mode? Would I be better off skipping the mlock process for single-user runs?
Thanks,
Tony
|
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Darwin-kernel mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden