On 2026/5/27 13:25, Michael S. Tsirkin wrote: > On Wed, May 27, 2026 at 11:23:23AM +0800, Miaohe Lin wrote: >> On 2026/5/21 22:09, Michael S. Tsirkin wrote: >>> On Wed, May 20, 2026 at 06:20:13PM -0400, Michael S. Tsirkin wrote: >>>> When a guest reports free pages to the hypervisor via virtio-balloon's >>>> free page reporting, the host typically zeros those pages when reclaiming >>>> their backing memory (e.g., via MADV_DONTNEED on anonymous mappings). >>>> When the guest later reallocates those pages, the kernel zeros them >>>> again, redundantly. >>> >>> FYI Sashiko reported a couple of issues. Mostly false positives but >>> I tweaked commit log to make it clearer. But also a couple of >>> real issues. So far I have this diff on top: >>> >>> ---> >>> >>> Changes from v8 to v9 candidate (code only): >>> >>> 1. mm/mempolicy.c (patch 1: mm: mempolicy: fix interleave index calculation) >>> Combine vm_pgoff and VMA offset into a single expression before >>> shifting, fixing carry loss for file-backed VMAs with unaligned >>> vm_pgoff. >>> >>> 2. mm/memory-failure.c (patch 2: mm: memory-failure: serialize >>> TestSetPageHWPoison with zone->lock) >>> Wrap ClearPageHWPoison in retry path with zone->lock too. >> >> It seems TestClearPageHWPoison and SetPageHWPoison are missing. Should we >> serialize them with zone->lock too? >> >> Thanks. >> . > > I don't think so. As far as I could tell, none of these are called on > pages that could be in the buddy. And all the non atomic page flags > games we play are only on pages in the buddy.
I scanned the code and it seems no one breaks the game. So I agree with you. Thanks. .
