On Fri, 19 Mar 2021 10:51:27 -0700 Minchan Kim <minchan@xxxxxxxxxx> wrote: > Pages containing buffer_heads that are in one of the per-CPU > buffer_head LRU caches will be pinned and thus cannot be migrated. > This can prevent CMA allocations from succeeding, which are often used > on platforms with co-processors (such as a DSP) that can only use > physically contiguous memory. It can also prevent memory > hot-unplugging from succeeding, which involves migrating at least > MIN_MEMORY_BLOCK_SIZE bytes of memory, which ranges from 8 MiB to 1 > GiB based on the architecture in use. > > Correspondingly, invalidate the BH LRU caches before a migration > starts and stop any buffer_head from being cached in the LRU caches, > until migration has finished. > > Tested-by: Oliver Sang <oliver.sang@xxxxxxxxx> > Reported-by: kernel test robot <oliver.sang@xxxxxxxxx> > Signed-off-by: Chris Goldsworthy <cgoldswo@xxxxxxxxxxxxxx> > Signed-off-by: Minchan Kim <minchan@xxxxxxxxxx> The signoff chain ordering might mean that Chris was the primary author, but there is no From:him. Please clarify?
