Allowing small allocations to fail

Posted Mar 13, 2015 7:35 UTC (Fri) by dlang (guest, #313)
In reply to: Allowing small allocations to fail by epa
Parent article: Allowing small allocations to fail

so what do you do when you can't notify userspace? For example, a memory allocation failure when you are trying to write data to disk and the program that created the data has already exited.

Allowing small allocations to fail

Posted Mar 13, 2015 7:35 UTC (Fri) by dlang (guest, #313) [Link]

remember that these 'too small to fail' allocations are allocations made by the kernel, not ones made by userspace via malloc or similar.

Allowing small allocations to fail

Posted Mar 13, 2015 16:08 UTC (Fri) by epa (subscriber, #39769) [Link]

The general principle is to notify the caller. If the caller was a userspace program that made a system call, and the system call can't complete because there isn't enough memory, you return a failure status such as ENOMEM. If the caller was a kernel routine, again you return the failure status. In neither case is hanging indefinitely really a sensible thing to do - although certainly a limited amount of waiting and retrying can be a good idea.