From 8fa1a21c6edc2bf7de85984944848ab9ac49e937 Mon Sep 17 00:00:00 2001 From: Fabiano Rosas Date: Thu, 21 Mar 2024 17:12:42 -0300 Subject: [PATCH] migration/multifd: Fix clearing of mapped-ram zero pages When the zero page detection is done in the multifd threads, we need to iterate the second part of the pages->offset array and clear the file bitmap for each zero page. The piece of code we merged to do that is wrong. The reason this has passed all the tests is because the bitmap is initialized with zeroes already, so clearing the bits only really has an effect during live migration and when a data page goes from having data to no data. Fixes: 303e6f54f9 ("migration/multifd: Implement zero page transmission on the multifd thread.") Signed-off-by: Fabiano Rosas Link: https://lore.kernel.org/r/20240321201242.6009-1-farosas@suse.de Signed-off-by: Peter Xu --- migration/multifd.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/migration/multifd.c b/migration/multifd.c index d2f0238f70..2802afe79d 100644 --- a/migration/multifd.c +++ b/migration/multifd.c @@ -111,7 +111,6 @@ void multifd_send_channel_created(void) static void multifd_set_file_bitmap(MultiFDSendParams *p) { MultiFDPages_t *pages = p->pages; - uint32_t zero_num = p->pages->num - p->pages->normal_num; assert(pages->block); @@ -119,7 +118,7 @@ static void multifd_set_file_bitmap(MultiFDSendParams *p) ramblock_set_file_bmap_atomic(pages->block, pages->offset[i], true); } - for (int i = p->pages->num; i < zero_num; i++) { + for (int i = p->pages->normal_num; i < p->pages->num; i++) { ramblock_set_file_bmap_atomic(pages->block, pages->offset[i], false); } }