Messages in this thread | | | From | Mina Almasry <> | Date | Mon, 13 Jan 2020 14:21:33 -0800 | Subject | Re: [PATCH v9 1/8] hugetlb_cgroup: Add hugetlb_cgroup reservation counter |
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> >> 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.
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