This is a note to let you know that I've just added the patch titled
hv_balloon: Balloon up according to request page number
to the 4.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
hv_balloon-balloon-up-according-to-request-page-number.patch
and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From d33c240d47dab4fd15123d9e73fc8810cbc6ed6a Mon Sep 17 00:00:00 2001
From: Tianyu Lan <Tianyu.Lan@xxxxxxxxxxxxx>
Date: Sat, 25 Jan 2020 16:50:47 -0500
Subject: hv_balloon: Balloon up according to request page number
From: Tianyu Lan <Tianyu.Lan@xxxxxxxxxxxxx>
commit d33c240d47dab4fd15123d9e73fc8810cbc6ed6a upstream.
Current code has assumption that balloon request memory size aligns
with 2MB. But actually Hyper-V doesn't guarantee such alignment. When
balloon driver receives non-aligned balloon request, it produces warning
and balloon up more memory than requested in order to keep 2MB alignment.
Remove the warning and balloon up memory according to actual requested
memory size.
Fixes: f6712238471a ("hv: hv_balloon: avoid memory leak on alloc_error of 2MB memory block")
Cc: stable@xxxxxxxxxxxxxxx
Reviewed-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
Signed-off-by: Tianyu Lan <Tianyu.Lan@xxxxxxxxxxxxx>
Reviewed-by: Michael Kelley <mikelley@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/hv/hv_balloon.c | 13 +++----------
1 file changed, 3 insertions(+), 10 deletions(-)
--- a/drivers/hv/hv_balloon.c
+++ b/drivers/hv/hv_balloon.c
@@ -1170,10 +1170,7 @@ static unsigned int alloc_balloon_pages(
unsigned int i = 0;
struct page *pg;
- if (num_pages < alloc_unit)
- return 0;
-
- for (i = 0; (i * alloc_unit) < num_pages; i++) {
+ for (i = 0; i < num_pages / alloc_unit; i++) {
if (bl_resp->hdr.size + sizeof(union dm_mem_page_range) >
PAGE_SIZE)
return i * alloc_unit;
@@ -1207,7 +1204,7 @@ static unsigned int alloc_balloon_pages(
}
- return num_pages;
+ return i * alloc_unit;
}
static void balloon_up(struct work_struct *dummy)
@@ -1222,9 +1219,6 @@ static void balloon_up(struct work_struc
long avail_pages;
unsigned long floor;
- /* The host balloons pages in 2M granularity. */
- WARN_ON_ONCE(num_pages % PAGES_IN_2M != 0);
-
/*
* We will attempt 2M allocations. However, if we fail to
* allocate 2M chunks, we will go back to 4k allocations.
@@ -1234,14 +1228,13 @@ static void balloon_up(struct work_struc
avail_pages = si_mem_available();
floor = compute_balloon_floor();
- /* Refuse to balloon below the floor, keep the 2M granularity. */
+ /* Refuse to balloon below the floor. */
if (avail_pages < num_pages || avail_pages - num_pages < floor) {
pr_warn("Balloon request will be partially fulfilled. %s\n",
avail_pages < num_pages ? "Not enough memory." :
"Balloon floor reached.");
num_pages = avail_pages > floor ? (avail_pages - floor) : 0;
- num_pages -= num_pages % PAGES_IN_2M;
}
while (!done) {
Patches currently in stable-queue which might be from Tianyu.Lan@xxxxxxxxxxxxx are
queue-4.14/hv_balloon-balloon-up-according-to-request-page-number.patch
