diff options
Diffstat (limited to 'mm/page_isolation.c')
| -rw-r--r-- | mm/page_isolation.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/mm/page_isolation.c b/mm/page_isolation.c index 89c19c0feadb..da0f6e1ae01e 100644 --- a/mm/page_isolation.c +++ b/mm/page_isolation.c @@ -187,6 +187,14 @@ __first_valid_page(unsigned long pfn, unsigned long nr_pages) * pageblocks we may have modified and return -EBUSY to caller. This * prevents two threads from simultaneously working on overlapping ranges. * + * Please note that there is no strong synchronization with the page allocator + * either. Pages might be freed while their page blocks are marked ISOLATED. + * In some cases pages might still end up on pcp lists and that would allow + * for their allocation even when they are in fact isolated already. Depending + * on how strong of a guarantee the caller needs drain_all_pages might be needed + * (e.g. __offline_pages will need to call it after check for isolated range for + * a next retry). + * * Return: the number of isolated pageblocks on success and -EBUSY if any part * of range cannot be isolated. */ |