On 2026/9/22 17:14, Breno Leitao wrote: > Hello Miaohe, > > On Tue, Sep 22, 2026 at 02:27:59PM +0800, Miaohe Lin wrote: >>> A bit is never cleared, which is a known limitation: it stands for a >>> whole unit, so an unpoison of one frame cannot tell whether the unit as a >>> whole is good again. >> >> Thanks for your patches. I have a question about unpoison: If a bit is never >> cleared, after we do some memory-failure+unpoison tests, kexec will lose the >> tested memory without reboot? > > Correct, A bit stands for a 2M unit, so every tested page that falls in > a distinct unit costs 2M in each kernel after the kexec. > > Worth being precise about the state today: the unpoison itself works. > The frame goes back to the allocator and num_poisoned_pages drops. Only > the bit stays, so the next kernel poisons the frame again. Test loop > in, memory out, and nothing gives it back. > > Important to say that nothing block us from unpoison the bitmap, and in > fact my initial patchset had it. I also _think_ we should unpoison the > bitmap once we unpoison the page. > > I have just kept it out of this patch in order to simplify the patchset and > get the basis correct, and then evolve on top of it. >
Makes sense to me. Thanks for your work. > That said, If you think this is a must have in first patchset, I am more > than happy to do it now, but just keep it in mind that it will grow the > patchset by about 2 extra functions. > > Thanks the review, > --breno > . >
