On Wed, Nov 06, 2019 at 08:11:44PM +0000, Dr. David Alan Gilbert wrote: >* Wei Yang (richardw.y...@linux.intel.com) wrote: >> This patch set tries enable compress during postcopy. >> >> postcopy requires to place a whole host page, while migration thread migrate >> memory in target page size. This makes postcopy need to collect all target >> pages in one host page before placing via userfaultfd. >> >> To enable compress during postcopy, there are two problems to solve: >> >> 1. Random order for target page arrival >> 2. Target pages in one host page arrives without interrupt by target >> page from other host page >> >> The first one is handled by counting the number of target pages arrived >> instead of the last target page arrived. >> >> The second one is handled by: >> >> 1. Flush compress thread for each host page >> 2. Wait for decompress thread for before placing host page >> >> With the combination of these two changes, compress is enabled during >> postcopy. > >What have you tested this with? 2MB huge pages I guess? >
I tried with this qemu option: -object memory-backend-file,id=mem1,mem-path=/dev/hugepages/guest2,size=4G \ -device pc-dimm,id=dimm1,memdev=mem1 /dev/hugepages/guest2 is a file under hugetlbfs hugetlbfs on /dev/hugepages type hugetlbfs (rw,relatime,pagesize=2M) >Dave > >> Wei Yang (6): >> migration/postcopy: reduce memset when it is zero page and >> matches_target_page_size >> migration/postcopy: wait for decompress thread in precopy >> migration/postcopy: count target page number to decide the >> place_needed >> migration/postcopy: set all_zero to true on the first target page >> migration/postcopy: enable random order target page arrival >> migration/postcopy: enable compress during postcopy >> >> migration/migration.c | 11 -------- >> migration/ram.c | 65 ++++++++++++++++++++++++++++++------------- >> 2 files changed, 45 insertions(+), 31 deletions(-) >> >> -- >> 2.17.1 >> >-- >Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK -- Wei Yang Help you, Help me