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| author | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-09-21 09:23:55 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-09-21 09:23:55 +0200 |
| commit | 33f16b25a091687388152d4b29593a39d819aa22 (patch) | |
| tree | 34a8ef8acf3f14ca0e4f514756222876d00ff202 /mm/page_isolation.c | |
| parent | 23f87274f0ad4a9167de23a330ed88966634fdf6 (diff) | |
| parent | ba4f184e126b751d1bffad5897f263108befc780 (diff) | |
Merge 5.9.0-rc6 into tty-next
We need the tty/serial fixes in here and this resolves a merge issue in
the 8250 driver.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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 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. */ |