On Wed, Feb 06, 2019 at 02:23:28PM +0100, Juan Quintela wrote: > I haven't seend any problem about using 64 or 128. And it make much > less contention on the locks. Just change it.
Isn't there a issue with having a fixed page count given the very different default page sizes across architectures ? x86 is 4kb pages, while ppc64 uses 64kb pages IIUC. This would mean current value of 64 pages, would correspond to 1/4 MB on x86, and 4 MB on ppc64. The new value would be 1/2 MB on x86 and 8 MB on ppc64. Should we instead be measuring this tunable in units that are independant of page size ? eg meansure in KB, with a requirement that the value is a multiple of the page size. Then set the default to 512 KB ? > > Signed-off-by: Juan Quintela <quint...@redhat.com> > --- > migration/migration.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/migration/migration.c b/migration/migration.c > index ef1d53cde2..f673486679 100644 > --- a/migration/migration.c > +++ b/migration/migration.c > @@ -81,7 +81,7 @@ > /* The delay time (in ms) between two COLO checkpoints */ > #define DEFAULT_MIGRATE_X_CHECKPOINT_DELAY (200 * 100) > #define DEFAULT_MIGRATE_MULTIFD_CHANNELS 2 > -#define DEFAULT_MIGRATE_MULTIFD_PAGE_COUNT 16 > +#define DEFAULT_MIGRATE_MULTIFD_PAGE_COUNT 128 > > /* Background transfer rate for postcopy, 0 means unlimited, note > * that page requests can still exceed this limit. > -- > 2.20.1 > > Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|
