If __isolate_free_page() fails, avoid adding to freelist so we don't call map_pages() with it.
Signed-off-by: David Rientjes <[email protected]> --- Fix for mm-compaction-split-freepages-without-holding-the-zone-lock.patch in -mm. mm/compaction.c | 29 +++++++++++++---------------- 1 file changed, 13 insertions(+), 16 deletions(-) diff --git a/mm/compaction.c b/mm/compaction.c --- a/mm/compaction.c +++ b/mm/compaction.c @@ -494,24 +494,21 @@ static unsigned long isolate_freepages_block(struct compact_control *cc, /* Found a free page, will break it into order-0 pages */ order = page_order(page); - isolated = __isolate_free_page(page, page_order(page)); + isolated = __isolate_free_page(page, order); + if (!isolated) + goto isolate_fail; set_page_private(page, order); total_isolated += isolated; list_add_tail(&page->lru, freelist); - - /* If a page was split, advance to the end of it */ - if (isolated) { - cc->nr_freepages += isolated; - if (!strict && - cc->nr_migratepages <= cc->nr_freepages) { - blockpfn += isolated; - break; - } - - blockpfn += isolated - 1; - cursor += isolated - 1; - continue; + cc->nr_freepages += isolated; + if (!strict && cc->nr_migratepages <= cc->nr_freepages) { + blockpfn += isolated; + break; } + /* Advance to end of split page */ + blockpfn += isolated - 1; + cursor += isolated - 1; + continue; isolate_fail: if (strict) @@ -622,7 +619,7 @@ isolate_freepages_range(struct compact_control *cc, */ } - /* split_free_page does not map the pages */ + /* __isolate_free_page() does not map the pages */ map_pages(&freelist); if (pfn < end_pfn) { @@ -1124,7 +1121,7 @@ static void isolate_freepages(struct compact_control *cc) } } - /* split_free_page does not map the pages */ + /* __isolate_free_page() does not map the pages */ map_pages(freelist); /*
