On Tue 01-03-16 19:20:24, Michael S. Tsirkin wrote: > On Tue, Mar 01, 2016 at 06:17:58PM +0100, Michal Hocko wrote: [...] > > Sorry, I could have been more verbose... The code would have to make sure > > that the mm is still alive before calling g-u-p by > > atomic_inc_not_zero(&mm->mm_users) and fail if the user count dropped to > > 0 in the mean time. See how fs/proc/task_mmu.c does that (proc_mem_open > > + m_start + m_stop. > > > > The biggest advanatage would be that the mm address space pin would be > > only for the particular operation. Not sure whether that is possible in > > the driver though. Anyway pinning the mm for a potentially unbounded > > amount of time doesn't sound too nice. > > Hmm that would be another atomic on data path ... > I'd have to explore that. Did you have any chance to look into this? -- Michal Hocko SUSE Labs -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>