[PATCH V2 1/2] Drivers: hv: balloon: Fix a bug in the hot-add code

From: K. Y. Srinivasan
Date: Mon Jul 15 2013 - 01:00:39 EST


As we hot-add 128 MB chunks of memory, we wait to ensure that the memory
is onlined before attempting to hot-add the next chunk. If the udev rule for
memory hot-add is not executed within the allowed time, we would rollback the
state and abort further hot-add. Since the hot-add has succeeded and the only
failure is that the memory is not onlined within the allowed time, we should not
be rolling back the state. Fix this bug.

Signed-off-by: K. Y. Srinivasan <kys@xxxxxxxxxxxxx>
Cc: Stable <stable@xxxxxxxxxxxxxxx>
---
drivers/hv/hv_balloon.c | 13 +++++--------
1 files changed, 5 insertions(+), 8 deletions(-)

diff --git a/drivers/hv/hv_balloon.c b/drivers/hv/hv_balloon.c
index 4c605c7..61b7351 100644
--- a/drivers/hv/hv_balloon.c
+++ b/drivers/hv/hv_balloon.c
@@ -562,7 +562,7 @@ static void hv_mem_hot_add(unsigned long start, unsigned long size,
struct hv_hotadd_state *has)
{
int ret = 0;
- int i, nid, t;
+ int i, nid;
unsigned long start_pfn;
unsigned long processed_pfn;
unsigned long total_pfn = pfn_count;
@@ -607,14 +607,11 @@ static void hv_mem_hot_add(unsigned long start, unsigned long size,

/*
* Wait for the memory block to be onlined.
+ * Since the hot add has succeeded, it is ok to
+ * proceed even if the pages in the hot added region
+ * have not been "onlined" within the allowed time.
*/
- t = wait_for_completion_timeout(&dm_device.ol_waitevent, 5*HZ);
- if (t == 0) {
- pr_info("hot_add memory timedout\n");
- has->ha_end_pfn -= HA_CHUNK;
- has->covered_end_pfn -= processed_pfn;
- break;
- }
+ wait_for_completion_timeout(&dm_device.ol_waitevent, 5*HZ);

}

--
1.7.4.1

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