Messages in this thread | | | Subject | Re: [PATCH v3 1/2] mm: introduce process_mrelease system call | From | David Hildenbrand <> | Date | Fri, 23 Jul 2021 10:15:30 +0200 |
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On 23.07.21 10:11, Suren Baghdasaryan wrote: > > > On Thu, Jul 22, 2021, 11:20 PM Michal Hocko <mhocko@suse.com > <mailto:mhocko@suse.com>> wrote: > > On Thu 22-07-21 21:47:56, Suren Baghdasaryan wrote: > > On Thu, Jul 22, 2021, 7:04 PM Shakeel Butt <shakeelb@google.com > <mailto:shakeelb@google.com>> wrote: > > > > > On Thu, Jul 22, 2021 at 6:14 PM Suren Baghdasaryan > <surenb@google.com <mailto:surenb@google.com>> > > > wrote: > > > > > > > [...] > > > > + > > > > + mmap_read_lock(mm); > > > > > > How about mmap_read_trylock(mm) and return -EAGAIN on failure? > > > > > > > That sounds like a good idea. Thanks! I'll add that in the next > respin. > > Why is that a good idea? Can you do anything meaningful about the > failure other than immediately retry the syscall and hope for the best? > > > I was thinking if this syscall implements "best effort without blocking" > approach then for a more strict usage user can simply retry. However > retrying means issuing another syscall, so additional overhead... > I guess such "best effort" approach would be unusual for a syscall, so > maybe we can keep it as it is now and if such "do not block" mode is > needed we can use flags to implement it later?
The process is dying, so I am not sure what we are trying to optimize here in respect to locking ...
-- Thanks,
David / dhildenb
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