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| author | Dr. David Alan Gilbert <dgilbert@redhat.com> | 2015-11-05 18:11:20 +0000 |
|---|---|---|
| committer | Juan Quintela <quintela@redhat.com> | 2015-11-10 15:00:28 +0100 |
| commit | f9527107570853b6a4a0903e4b0733747d02e74a (patch) | |
| tree | e329bdcffa895424e404c7f270ea9ecd97a79a8e /trace-events | |
| parent | 27c6825bd3749758fb9fcad44f3759f593be8506 (diff) | |
| download | qemu-f9527107570853b6a4a0903e4b0733747d02e74a.tar.gz | |
Postcopy: Mark nohugepage before discard
Prior to servicing userfault requests we must ensure we've not got
huge pages in the area that might include non-transferred memory,
since a hugepage could incorrectly mark the whole huge page as present.
We mark the area as non-huge page (nhp) just before we perform
discards; the discard code now tells us to discard any areas
that haven't been sent (as well as any that are redirtied);
any already formed transparent-huge-pages get fragmented
by this discard process if they cotnain any discards.
Transparent huge pages that have been entirely transferred
and don't contain any discards are not broken by this mechanism;
they stay as huge pages.
By starting postcopy after a full precopy pass, many of the pages
then stay as huge pages; this is important for maintaining performance
after the end of the migration.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Diffstat (limited to 'trace-events')
| -rw-r--r-- | trace-events | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/trace-events b/trace-events index a89778f99b..452435d33f 100644 --- a/trace-events +++ b/trace-events @@ -1556,6 +1556,7 @@ postcopy_discard_send_range(const char *ramblock, unsigned long start, unsigned postcopy_ram_discard_range(void *start, size_t length) "%p,+%zx" postcopy_cleanup_range(const char *ramblock, void *host_addr, size_t offset, size_t length) "%s: %p offset=%zx length=%zx" postcopy_init_range(const char *ramblock, void *host_addr, size_t offset, size_t length) "%s: %p offset=%zx length=%zx" +postcopy_nhp_range(const char *ramblock, void *host_addr, size_t offset, size_t length) "%s: %p offset=%zx length=%zx" postcopy_place_page(void *host_addr) "host=%p" postcopy_place_page_zero(void *host_addr) "host=%p" postcopy_ram_enable_notify(void) "" |