Messages in this thread Patch in this message | | | From | Yinghai Lu <> | Subject | [PATCH v3 2/2] range: Do not add new blank slot with add_range_with_merge | Date | Thu, 13 Jun 2013 13:17:02 -0700 |
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Joshua reported: Commit cd7b304dfaf1 (x86, range: fix missing merge during add range) broke mtrr cleanup on his setup in 3.9.5. corresponding commit in upstream is fbe06b7bae7c.
The reason is add_range_with_merge could generate blank spot.
We could avoid that by searching new expanded start/end, that new range should include all connected ranges in range array. At last add the new expanded start/end to the range array. Also move up left array so do not add new blank slot in the range array.
-v2: move left array to avoid enhance add_range() -v3: include fix from Joshua about memmove declaring when DYN_DEBUG is used.
Reported-by: Joshua Covington <joshuacov@googlemail.com> Tested-by: Joshua Covington <joshuacov@googlemail.com> Signed-off-by: Yinghai Lu <yinghai@kernel.org> Cc: <stable@vger.kernel.org> v3.9
--- kernel/range.c | 23 ++++++++++++----------- 1 file changed, 12 insertions(+), 11 deletions(-)
Index: linux-2.6/kernel/range.c =================================================================== --- linux-2.6.orig/kernel/range.c +++ linux-2.6/kernel/range.c @@ -4,7 +4,7 @@ #include <linux/kernel.h> #include <linux/init.h> #include <linux/sort.h> - +#include <linux/string.h> #include <linux/range.h> int add_range(struct range *range, int az, int nr_range, u64 start, u64 end) @@ -32,9 +32,8 @@ int add_range_with_merge(struct range *r if (start >= end) return nr_range; - /* Try to merge it with old one: */ + /* get new start/end: */ for (i = 0; i < nr_range; i++) { - u64 final_start, final_end; u64 common_start, common_end; if (!range[i].end) @@ -45,14 +44,16 @@ int add_range_with_merge(struct range *r if (common_start > common_end) continue; - final_start = min(range[i].start, start); - final_end = max(range[i].end, end); - - /* clear it and add it back for further merge */ - range[i].start = 0; - range[i].end = 0; - return add_range_with_merge(range, az, nr_range, - final_start, final_end); + /* new start/end, will add it back at last */ + start = min(range[i].start, start); + end = max(range[i].end, end); + + memmove(&range[i], &range[i + 1], + (nr_range - (i + 1)) * sizeof(range[i])); + range[nr_range - 1].start = 0; + range[nr_range - 1].end = 0; + nr_range--; + i--; } /* Need to add it: */
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