On Thu, Nov 11, 2021, Ben Gardon wrote: > On Thu, Nov 11, 2021 at 2:14 PM Sean Christopherson <seanjc@xxxxxxxxxx> wrote: > > Fixes: fbb158cb88b6 ("KVM: x86/mmu: Revert "Revert "KVM: MMU: zap pages in batch""") > > Reported-by: David Matlack <dmatlack@xxxxxxxxxx> > > Cc: Ben Gardon <bgardon@xxxxxxxxxx> > > Cc: stable@xxxxxxxxxxxxxxx > > Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx> > > Reviewed-by: Ben Gardon <bgardon@xxxxxxxxxx> > > While I can see this fixing the above stall, there's still a potential > issue where zapped_obsolete_pages can accumulate an arbitrary number > of pages from multiple batches of zaps. If this list gets very large, > we could see a stall after the loop while trying to free the pages. > I'm not aware of this ever happening, but it could be worth yielding > during that freeing process as well. Ya. I tagged this one for stable because its very much a regression that I introduced when reverting the revert, i.e. the very original implemenation worked. Sadly, I did not get to do a triple revert :-)