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authorDavid S. Miller <davem@davemloft.net>2020-09-23 02:45:34 +0300
committerDavid S. Miller <davem@davemloft.net>2020-09-23 02:45:34 +0300
commit3ab0a7a0c349a1d7beb2bb371a62669d1528269d (patch)
treed2ae17c3bfc829ce0c747ad97021cd4bc8fb11dc /mm/page_isolation.c
parent92ec804f3dbf0d986f8e10850bfff14f316d7aaf (diff)
parent805c6d3c19210c90c109107d189744e960eae025 (diff)
downloadlinux-3ab0a7a0c349a1d7beb2bb371a62669d1528269d.tar.xz
Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Two minor conflicts: 1) net/ipv4/route.c, adding a new local variable while moving another local variable and removing it's initial assignment. 2) drivers/net/dsa/microchip/ksz9477.c, overlapping changes. One pretty prints the port mode differently, whilst another changes the driver to try and obtain the port mode from the port node rather than the switch node. Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'mm/page_isolation.c')
-rw-r--r--mm/page_isolation.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/mm/page_isolation.c b/mm/page_isolation.c
index 242c03121d73..63a3db10a8c0 100644
--- a/mm/page_isolation.c
+++ b/mm/page_isolation.c
@@ -170,6 +170,14 @@ __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.
*/