Re: [PATCH v6 updated 9/11] mm/mremap: Fix race between mremap and pageout

2021-05-25 Thread Linus Torvalds
On Mon, May 24, 2021 at 10:44 PM A lneesh Kumar K.V wrote: > > Should we worry about the below race. The window would be small > > CPU 1 CPU 2 CPU 3 > > mremap(old_addr, new_addr) page_shrinker/try_to_unmap_one > > mmap_write_lock_ki

Re: [PATCH v6 updated 9/11] mm/mremap: Fix race between mremap and pageout

2021-05-25 Thread A lneesh Kumar K.V
Linus Torvalds writes: > On Mon, May 24, 2021 at 3:38 AM Aneesh Kumar K.V > wrote: >> >> Avoid the above race with MOVE_PMD by holding pte ptl in mremap and waiting >> for >> parallel pagetable walk to finish operating on pte before updating new_pmd > > Ack on the concept. Should we worry abo

Re: [PATCH v6 updated 9/11] mm/mremap: Fix race between mremap and pageout

2021-05-24 Thread Linus Torvalds
On Mon, May 24, 2021 at 3:38 AM Aneesh Kumar K.V wrote: > > Avoid the above race with MOVE_PMD by holding pte ptl in mremap and waiting > for > parallel pagetable walk to finish operating on pte before updating new_pmd Ack on the concept. However, not so much on the patch. Odd whitespace chang