> >> On 12/17/19 3:16 PM, Mina Almasry wrote: > > > > The design we went with based on previous discussions is as follows: > > hugetlb pages faulted without a prior reservation get accounted at > > fault time, rather than reservation time, and if the fault causes the > > counter to cross the limit, the charge fails, hence the fault fails, > > hence the process gets sigbus'd. > > Ok, sorry I did not recall the design discussion. > No worries! It has indeed been a while since that discussion. > > This means that one counter I'm adding here can cover both use cases: > > if the userspace uses MAP_NORESERVE, then their memory is accounted at > > fault time and they may get sigbus'd. > > Let's make sure this is clearly documented. Someone could be surprised > if their application not using reserves gets a SIGBUS because there is a > reserve limit. I have some stuff on that already in the docs patch, but I'll beef that section up to ensure there is no confusion.
