Hi Dave, On 2020/6/16 17:35, Dr. David Alan Gilbert wrote: > * Keqian Zhu (zhukeqi...@huawei.com) wrote: >> real_dirty_pages becomes equal to total ram size after dirty log sync >> in ram_init_bitmaps, the reason is that the bitmap of ramblock is >> initialized to be all set, so old path counts them as "real dirty" at >> beginning. >> >> This causes wrong dirty rate and false positive throttling at the end >> of first ram save iteration. >> >> Signed-off-by: Keqian Zhu <zhukeqi...@huawei.com> > > Since this function already returns num_dirty, why not just change the > caller to increment a counter based off the return value? Yes, that would be better :-) .
> > Can you point to the code which is using this value that triggers the > throttle? > In migration_trigger_throttle(), rs->num_dirty_pages_period is used. And it corresponds to real_dirty_pages here. Thanks, Keqian > Dave > > [...] >> >> > -- > Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK > > . >
