diff options
| author | K. Y. Srinivasan | 2013-02-08 15:57:16 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman | 2013-02-08 15:42:01 -0800 |
| commit | 1c7db96f6feac95d90200ddd0f9b5d94614ea759 (patch) | |
| tree | 5facf08f6c2ca913b1ce519b212daf61a3478c22 | |
| parent | e500d158fb07794724f12655f2eb5702fec613c4 (diff) | |
Drivers: hv: balloon: Prevent the host from ballooning the guest too low
Based on the amount of memory being managed set a floor on how low the
guest can be ballooned.
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/hv/hv_balloon.c | 35 |
1 files changed, 34 insertions, 1 deletions
diff --git a/drivers/hv/hv_balloon.c b/drivers/hv/hv_balloon.c index f8fc99600de8..37873213e24f 100644 --- a/drivers/hv/hv_balloon.c +++ b/drivers/hv/hv_balloon.c @@ -523,6 +523,34 @@ static void process_info(struct hv_dynmem_device *dm, struct dm_info_msg *msg) } } +unsigned long compute_balloon_floor(void) +{ + unsigned long min_pages; +#define MB2PAGES(mb) ((mb) << (20 - PAGE_SHIFT)) + /* Simple continuous piecewiese linear function: + * max MiB -> min MiB gradient + * 0 0 + * 16 16 + * 32 24 + * 128 72 (1/2) + * 512 168 (1/4) + * 2048 360 (1/8) + * 8192 552 (1/32) + * 32768 1320 + * 131072 4392 + */ + if (totalram_pages < MB2PAGES(128)) + min_pages = MB2PAGES(8) + (totalram_pages >> 1); + else if (totalram_pages < MB2PAGES(512)) + min_pages = MB2PAGES(40) + (totalram_pages >> 2); + else if (totalram_pages < MB2PAGES(2048)) + min_pages = MB2PAGES(104) + (totalram_pages >> 3); + else + min_pages = MB2PAGES(296) + (totalram_pages >> 5); +#undef MB2PAGES + return min_pages; +} + /* * Post our status as it relates memory pressure to the * host. Host expects the guests to post this status @@ -552,9 +580,14 @@ static void post_status(struct hv_dynmem_device *dm) * The host expects the guest to report free memory. * Further, the host expects the pressure information to * include the ballooned out pages. + * For a given amount of memory that we are managing, we + * need to compute a floor below which we should not balloon. + * Compute this and add it to the pressure report. */ status.num_avail = val.freeram; - status.num_committed = vm_memory_committed() + dm->num_pages_ballooned; + status.num_committed = vm_memory_committed() + + dm->num_pages_ballooned + + compute_balloon_floor(); vmbus_sendpacket(dm->dev->channel, &status, sizeof(struct dm_status), |