On Thu, Apr 06, 2023 at 04:04:23PM +0200, Peter Zijlstra wrote: > On Thu, Apr 06, 2023 at 03:29:28PM +0200, Peter Zijlstra wrote: > > On Thu, Apr 06, 2023 at 09:38:50AM -0300, Marcelo Tosatti wrote: > > > > > > To actually hit this path you're doing something really dodgy. > > > > > > Apparently khugepaged is using the same infrastructure: > > > > > > $ grep tlb_remove_table khugepaged.c > > > tlb_remove_table_sync_one(); > > > tlb_remove_table_sync_one(); > > > > > > So just enabling khugepaged will hit that path. > > > > Urgh, WTF.. > > > > Let me go read that stuff :/ > > At the very least the one on collapse_and_free_pmd() could easily become > a call_rcu() based free. > > I'm not sure I'm following what collapse_huge_page() does just yet. DavidH, what do you thikn about reviving Jann's patches here: https://bugs.chromium.org/p/project-zero/issues/detail?id=2365#c1 Those are far more invasive, but afaict they seem to do the right thing.
