[Sorry this somehow slipped through cracks] On Tue 25-05-21 12:26:04, David Hildenbrand wrote: > The memory hot(un)plug documentation is outdated and incomplete. Most of > the content dates back to 2007, so it's time for a major overhaul. > > Let's rewrite, reorganize and update most parts of the documentation. In > addition to memory hot(un)plug, also add some details regarding > ZONE_MOVABLE, with memory hotunplug being one of its main consumers. > > The style of the document is also properly fixed that e.g., "restview" > renders it cleanly now. > > In the future, we might add some more details about virt users like > virtio-mem, the XEN balloon, the Hyper-V balloon and ppc64 dlpar. I haven't really checked the diff but rather looked at the final outcome. I have to say I like it a lot. Some places are going a bit too technical for an admin-guide but they are in minority (e.g. locking or altmap reference). If somebody feels strong then this could get into its own file but I wouldn't lose sleep over that. I would make one thing slightly more explicit though diff --git a/Documentation/admin-guide/mm/memory-hotplug.rst b/Documentation/admin-guide/mm/memory-hotplug.rst index c95f5c2b30dd..5b462aba89cc 100644 --- a/Documentation/admin-guide/mm/memory-hotplug.rst +++ b/Documentation/admin-guide/mm/memory-hotplug.rst @@ -568,6 +568,10 @@ Even with ZONE_MOVABLE, there are some corner cases where offlining a memory Further, when running into out of memory situations while migrating pages, or when still encountering permanently unmovable pages within ZONE_MOVABLE (-> BUG), memory offlining will keep retrying until it eventually succeeds. +The offlining context can be terminated by a fatal signal. A timeout based +offlining can be easily implemented by + + % timeout $TIMEOUT offline_block | failure_handling Locking Internals ================= In the future I would find some examples of a failure cases we have seen so far. E.g. offlining failure with dump_page example. > Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > Cc: Oscar Salvador <osalvador@xxxxxxx> > Cc: Michal Hocko <mhocko@xxxxxxxx> > Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx> > Cc: Mike Rapoport <rppt@xxxxxxxxxx> > Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> > Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx> > Cc: Anshuman Khandual <anshuman.khandual@xxxxxxx> > Cc: Muchun Song <songmuchun@xxxxxxxxxxxxx> > Cc: Pavel Tatashin <pasha.tatashin@xxxxxxxxxx> > Cc: Jonathan Corbet <corbet@xxxxxxx> > Cc: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx> > Cc: linux-doc@xxxxxxxxxxxxxxx > Signed-off-by: David Hildenbrand <david@xxxxxxxxxx> Acked-by: Michal Hocko <mhocko@xxxxxxxx> Thanks a lot David! -- Michal Hocko SUSE Labs
