On Sun, 17 Jul 2022, Hugh Dickins wrote: > On Mon, 18 Jul 2022, Liam Howlett wrote: > > Do you have the patch > > "maple_tree-Fix-stale-data-copy-in-mas_wr_node_store.patch"? It sounds > > like your issue fits this fix exactly. I was seeing the same issue with > > gcc 9.3.1 20200408 and this bug doesn't happen for me now. The logs > > you sent also fit the situation. I went through the same exercise > > (exorcism?) of debugging the various additions and removals of the VMA > > only to find the issue in the tree itself. The fix also modified the > > test code to detect the issue - which was actually hit but not detected > > in the existing test cases from a live capture of VMA activities. It is > > difficult to spot in the tree dump as well. I am sure I sent this to > > Andrew as it is included in v11 and did not show up in his diff, but I > > cannot find it on lore, perhaps I forgot to CC you? I've attached it > > here for you in case you missed it. > > Thanks! No, I never received that patch, nor can I see it on lore > or marc.info; but I (still) haven't looked at v11, and don't know > about Andrew's diff. Anyway, sounds exciting, I'm eager to stop > writing this mail and get to testing with that in - but please > let me know whether it's the mas_dead_leaves() or the __vma_adjust() > mods you attached previously, which you want me to leave out. I just went ahead with both of those still in, my do_mas_munmap() non-fix reverted, and your "Fix stale data copy" added: looks very promising so far, been running two hours without a problem. I do expect it to hit the migration entry !PageLocked BUG soon (as it quickly did on the laptop), but that's okay: I'll switch over to thinking about that BUG, so long as tonight's run does not crash in some other way. Hugh
