Re: kernel memory allocation failures

[Chuck Silvers <chuq%chuq.com@localhost>]

On Fri, Dec 11, 2015 at 11:00:06AM -0500, Christos Zoulas wrote:
> Fixing kmem_alloc() and friends not to fail under certain conditions might
> be possible, but it could lead to livelock scenarios where everything is
> stuck in the kernel waiting for resources to be freed.
> 
> Perhaps we should just explain that it is not the responsibility of the
> caller to check for the result of kmem_alloc() in the KM_WAIT case, and
> centralize the check in kmem_alloc() to make it panic() if it would
> return NULL? Is that better than fixing the 400+ calling sites?

I haven't looked see exactly what the internal conditions are that lead to
kmem_alloc(KM_SLEEP) returning NULL, so it's not clear whether having
kmem_alloc() retry or panic in that situation would be better.
but either of those would be better than adding code to all the callers.

-Chuck