On Wed, Jun 14, 2023 at 02:45:58PM +0800, mawupeng wrote: > > > On 2023/6/14 14:35, Greg KH wrote: > > On Wed, Jun 14, 2023 at 02:19:00PM +0800, Wupeng Ma wrote: > >> From: David Hildenbrand <david@xxxxxxxxxx> > >> > >> virtio-mem soon wants to use offline_and_remove_memory() memory that > >> exceeds a single Linux memory block (memory_block_size_bytes()). Let's > >> remove that restriction. > >> > >> Let's remember the old state and try to restore that if anything goes > >> wrong. While re-onlining can, in general, fail, it's highly unlikely to > >> happen (usually only when a notifier fails to allocate memory, and these > >> are rather rare). > >> > >> This will be used by virtio-mem to offline+remove memory ranges that are > >> bigger than a single memory block - for example, with a device block > >> size of 1 GiB (e.g., gigantic pages in the hypervisor) and a Linux memory > >> block size of 128MB. > >> > >> While we could compress the state into 2 bit, using 8 bit is much > >> easier. > >> > >> This handling is similar, but different to acpi_scan_try_to_offline(): > >> > >> a) We don't try to offline twice. I am not sure if this CONFIG_MEMCG > >> optimization is still relevant - it should only apply to ZONE_NORMAL > >> (where we have no guarantees). If relevant, we can always add it. > >> > >> b) acpi_scan_try_to_offline() simply onlines all memory in case > >> something goes wrong. It doesn't restore previous online type. Let's do > >> that, so we won't overwrite what e.g., user space configured. > >> > >> Reviewed-by: Wei Yang <richard.weiyang@xxxxxxxxxxxxxxxxx> > >> Cc: "Michael S. Tsirkin" <mst@xxxxxxxxxx> > >> Cc: Jason Wang <jasowang@xxxxxxxxxx> > >> Cc: Pankaj Gupta <pankaj.gupta.linux@xxxxxxxxx> > >> Cc: Michal Hocko <mhocko@xxxxxxxxxx> > >> Cc: Oscar Salvador <osalvador@xxxxxxx> > >> Cc: Wei Yang <richard.weiyang@xxxxxxxxxxxxxxxxx> > >> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > >> Signed-off-by: David Hildenbrand <david@xxxxxxxxxx> > >> Link: https://lore.kernel.org/r/20201112133815.13332-28-david@xxxxxxxxxx > >> Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx> > >> Acked-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > >> --- > >> mm/memory_hotplug.c | 105 +++++++++++++++++++++++++++++++++++++------- > >> 1 file changed, 89 insertions(+), 16 deletions(-) > > > > As you forwarded this patch on, you too need to sign-off on it. > > Thanks for reminding me. > > Signed-off-by: Ma Wupeng <mawupeng1@xxxxxxxxxx> > > > > > Also, what is the git id of the commit in Linus's tree? > > Sorry, here is the commit in Linus's tree. > > commit 8dc4bb58a146655eb057247d7c9d19e73928715b upstream. Please resend the change with both of these things fixed up, so I don't have to manually do it :) thanks, greg k-h
