Hi Peter, > On Sep 4, 2019, at 2:46 PM, Song Liu <[email protected]> wrote: > > perf_mmap() always increases user->locked_vm. As a result, "extra" could > grow bigger than "user_extra", which doesn't make sense. Here is an > example case: > > Note: Assume "user_lock_limit" is very small. > | # of perf_mmap calls |vma->vm_mm->pinned_vm|user->locked_vm| > | 0 | 0 | 0 | > | 1 | user_extra | user_extra | > | 2 | 3 * user_extra | 2 * user_extra| > | 3 | 6 * user_extra | 3 * user_extra| > | 4 | 10 * user_extra | 4 * user_extra| > > Fix this by maintaining proper user_extra and extra. > > Reported-by: Hechao Li <[email protected]> > Cc: Jie Meng <[email protected]> > Cc: Peter Zijlstra <[email protected]> > Signed-off-by: Song Liu <[email protected]>
Could you please share your feedbacks/comments on this one? Thanks, Song
