motorhead/qemu
1
0
Fork 0
mirror of https://github.com/Motorhead1991/qemu.git synced 2025-08-06 17:23:56 -06:00
Code Issues Projects Releases Packages Wiki Activity Actions

migration/multifd: solve zero page causing multiple page faults

Browse source 
Implemented recvbitmap tracking of received pages in multifd.

If the zero page appears for the first time in the recvbitmap, this
page is not checked and set.

If the zero page has already appeared in the recvbitmap, there is no
need to check the data but directly set the data to 0, because it is
unlikely that the zero page will be migrated multiple times.

Signed-off-by: Yuan Liu <yuan1.liu@intel.com>
Reviewed-by: Fabiano Rosas <farosas@suse.de>
Link: https://lore.kernel.org/r/20240401154110.2028453-2-yuan1.liu@intel.com
[peterx: touch up the comment, as the bitmap is used outside postcopy now]
Signed-off-by: Peter Xu <peterx@redhat.com>
This commit is contained in:
Yuan Liu 2024-04-01 23:41:10 +08:00 • committed by Peter Xu
parent dd03167725
commit 5ef7e26bdb
7 changed files with 12 additions and 2 deletions
Download patch file Download diff file Expand all files Collapse all files

4
migration/multifd-zero-page.c
View file

@ -80,8 +80,10 @@ void multifd_recv_zero_page_process(MultiFDRecvParams *p)
{
for (int i = 0; i < p->zero_num; i++) {
void *page = p->host + p->zero[i];
if (!buffer_is_zero(page, p->page_size)) {
if (ramblock_recv_bitmap_test_byte_offset(p->block, p->zero[i])) {
memset(page, 0, p->page_size);
} else {
ramblock_recv_bitmap_set_offset(p->block, p->zero[i]);
}
}
}