The patch titled
Subject: mm-hotplug-fix-offline-undo_isolate_page_range-v4
has been added to the -mm tree. Its filename is
mm-hotplug-fix-offline-undo_isolate_page_range-v4.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-hotplug-fix-offline-undo_isolate_page_range-v4.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-hotplug-fix-offline-undo_isolate_page_range-v4.patch
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------------------------------------------------------
From: Qian Cai <cai@xxxxxx>
Subject: mm-hotplug-fix-offline-undo_isolate_page_range-v4
v4: Further consolidate comments.
Turn on kernel-doc and add a stable tag per Michal.
Link: http://lkml.kernel.org/r/20190314150641.59358-1-cai@xxxxxx
Signed-off-by: Qian Cai <cai@xxxxxx>
Acked-by: Michal Hocko <mhocko@xxxxxxxx>
Reviewed-by: Oscar Salvador <osalvador@xxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
--- a/include/linux/page-isolation.h~mm-hotplug-fix-offline-undo_isolate_page_range-v4
+++ a/include/linux/page-isolation.h
@@ -41,16 +41,6 @@ int move_freepages_block(struct zone *zo
/*
* Changes migrate type in [start_pfn, end_pfn) to be MIGRATE_ISOLATE.
- * If specified range includes migrate types other than MOVABLE or CMA,
- * this will fail with -EBUSY.
- *
- * For isolating all pages in the range finally, the caller have to
- * free all pages in the range. test_page_isolated() can be used for
- * test it.
- *
- * The following flags are allowed (they can be combined in a bit mask)
- * SKIP_HWPOISON - ignore hwpoison pages
- * REPORT_FAILURE - report details about the failure to isolate the range
*/
int
start_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn,
--- a/mm/memory_hotplug.c~mm-hotplug-fix-offline-undo_isolate_page_range-v4
+++ a/mm/memory_hotplug.c
@@ -1576,7 +1576,7 @@ static int __ref __offline_pages(unsigne
{
unsigned long pfn, nr_pages;
long offlined_pages;
- int ret, node, count;
+ int ret, node, nr_isolate_pageblock;
unsigned long flags;
unsigned long valid_start, valid_end;
struct zone *zone;
@@ -1606,7 +1606,7 @@ static int __ref __offline_pages(unsigne
reason = "failure to isolate range";
goto failed_removal;
}
- count = ret;
+ nr_isolate_pageblock = ret;
arg.start_pfn = start_pfn;
arg.nr_pages = nr_pages;
@@ -1665,7 +1665,7 @@ static int __ref __offline_pages(unsigne
* pageblocks zone counter here.
*/
spin_lock_irqsave(&zone->lock, flags);
- zone->nr_isolate_pageblock -= count;
+ zone->nr_isolate_pageblock -= nr_isolate_pageblock;
spin_unlock_irqrestore(&zone->lock, flags);
/* removal success */
--- a/mm/page_isolation.c~mm-hotplug-fix-offline-undo_isolate_page_range-v4
+++ a/mm/page_isolation.c
@@ -160,28 +160,36 @@ __first_valid_page(unsigned long pfn, un
return NULL;
}
-/*
- * start_isolate_page_range() -- make page-allocation-type of range of pages
- * to be MIGRATE_ISOLATE.
- * @start_pfn: The lower PFN of the range to be isolated.
- * @end_pfn: The upper PFN of the range to be isolated.
- * @migratetype: migrate type to set in error recovery.
+/**
+ * start_isolate_page_range() - make page-allocation-type of range of pages to
+ * be MIGRATE_ISOLATE.
+ * @start_pfn: The lower PFN of the range to be isolated.
+ * @end_pfn: The upper PFN of the range to be isolated.
+ * start_pfn/end_pfn must be aligned to pageblock_order.
+ * @migratetype: Migrate type to set in error recovery.
+ * @flags: The following flags are allowed (they can be combined in
+ * a bit mask)
+ * SKIP_HWPOISON - ignore hwpoison pages
+ * REPORT_FAILURE - report details about the failure to
+ * isolate the range
*
* Making page-allocation-type to be MIGRATE_ISOLATE means free pages in
* the range will never be allocated. Any free pages and pages freed in the
- * future will not be allocated again.
- *
- * start_pfn/end_pfn must be aligned to pageblock_order.
- * Return the number of isolated pageblocks on success and -EBUSY if any part of
- * range cannot be isolated.
+ * future will not be allocated again. If specified range includes migrate types
+ * other than MOVABLE or CMA, this will fail with -EBUSY. For isolating all
+ * pages in the range finally, the caller have to free all pages in the range.
+ * test_page_isolated() can be used for test it.
*
* There is no high level synchronization mechanism that prevents two threads
- * from trying to isolate overlapping ranges. If this happens, one thread
+ * from trying to isolate overlapping ranges. If this happens, one thread
* will notice pageblocks in the overlapping range already set to isolate.
* This happens in set_migratetype_isolate, and set_migratetype_isolate
- * returns an error. We then clean up by restoring the migration type on
- * pageblocks we may have modified and return -EBUSY to caller. This
+ * returns an error. We then clean up by restoring the migration type on
+ * pageblocks we may have modified and return -EBUSY to caller. This
* prevents two threads from simultaneously working on overlapping ranges.
+ *
+ * Return: the number of isolated pageblocks on success and -EBUSY if any part
+ * of range cannot be isolated.
*/
int start_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn,
unsigned migratetype, int flags)
@@ -189,7 +197,7 @@ int start_isolate_page_range(unsigned lo
unsigned long pfn;
unsigned long undo_pfn;
struct page *page;
- int count = 0;
+ int nr_isolate_pageblock = 0;
BUG_ON(!IS_ALIGNED(start_pfn, pageblock_nr_pages));
BUG_ON(!IS_ALIGNED(end_pfn, pageblock_nr_pages));
@@ -203,10 +211,10 @@ int start_isolate_page_range(unsigned lo
undo_pfn = pfn;
goto undo;
}
- count++;
+ nr_isolate_pageblock++;
}
}
- return count;
+ return nr_isolate_pageblock;
undo:
for (pfn = start_pfn;
pfn < undo_pfn;
_
Patches currently in -mm which might be from cai@xxxxxx are
kasan-fix-variable-tag-set-but-not-used-warning.patch
mm-debug-add-a-cast-to-u64-for-atomic64_read.patch
kmemleak-skip-scanning-holes-in-the-bss-section.patch
kmemleak-skip-scanning-holes-in-the-bss-section-v2.patch
mm-hotplug-fix-offline-undo_isolate_page_range.patch
mm-hotplug-fix-offline-undo_isolate_page_range-v4.patch
mm-compaction-abort-search-if-isolation-fails-v2.patch
mm-hotplug-fix-notification-in-offline-error-path.patch
mm-fix-a-wrong-flag-in-set_migratetype_isolate.patch
mm-compaction-fix-an-undefined-behaviour.patch
