[v3,10/20] vmw_balloon: simplify vmballoon_send_get_target()
diff mbox series

Message ID 20180926191336.101885-11-namit@vmware.com
State New
Headers show
Series
  • vmw_balloon: compaction, shrinker, 64-bit, etc.
Related show

Commit Message

Nadav Amit Sept. 26, 2018, 7:13 p.m. UTC
As we want to leave as little as possible on the global balloon
structure, to avoid possible future races, we want to get rid sysinfo.
We can actually get the total_ram directly, and simplify the logic of
vmballoon_send_get_target() a little.

While we are doing that, let's return int and avoid mistakes due to
bool/int conversions.

Reviewed-by: Xavier Deguillard <xdeguillard@vmware.com>
Signed-off-by: Nadav Amit <namit@vmware.com>
---
 drivers/misc/vmw_balloon.c | 35 ++++++++++++++---------------------
 1 file changed, 14 insertions(+), 21 deletions(-)

Patch
diff mbox series

diff --git a/drivers/misc/vmw_balloon.c b/drivers/misc/vmw_balloon.c
index 0d9f223d463e..3c80a21e0f91 100644
--- a/drivers/misc/vmw_balloon.c
+++ b/drivers/misc/vmw_balloon.c
@@ -223,8 +223,6 @@  struct vmballoon {
 	struct dentry *dbg_entry;
 #endif
 
-	struct sysinfo sysinfo;
-
 	struct delayed_work dwork;
 
 	struct vmci_handle vmci_doorbell;
@@ -353,34 +351,29 @@  static u16 vmballoon_page_size(bool is_2m_page)
 	return 1;
 }
 
-/*
- * Retrieve desired balloon size from the host.
+/**
+ * vmballoon_send_get_target() - Retrieve desired balloon size from the host.
+ *
+ * @b: pointer to the balloon.
+ *
+ * Return: zero on success, EINVAL if limit does not fit in 32-bit, as required
+ * by the host-guest protocol and EIO if an error occurred in communicating with
+ * the host.
  */
-static bool vmballoon_send_get_target(struct vmballoon *b)
+static int vmballoon_send_get_target(struct vmballoon *b)
 {
 	unsigned long status;
 	unsigned long limit;
-	u32 limit32;
 
-	/*
-	 * si_meminfo() is cheap. Moreover, we want to provide dynamic
-	 * max balloon size later. So let us call si_meminfo() every
-	 * iteration.
-	 */
-	si_meminfo(&b->sysinfo);
-	limit = b->sysinfo.totalram;
+	limit = totalram_pages;
 
 	/* Ensure limit fits in 32-bits */
-	limit32 = (u32)limit;
-	if (limit != limit32)
-		return false;
+	if (limit != (u32)limit)
+		return -EINVAL;
 
 	status = vmballoon_cmd(b, VMW_BALLOON_CMD_GET_TARGET, limit, 0);
 
-	if (status == VMW_BALLOON_SUCCESS)
-		return true;
-
-	return false;
+	return status == VMW_BALLOON_SUCCESS ? 0 : -EIO;
 }
 
 static struct page *vmballoon_alloc_page(bool is_2m_page)
@@ -962,7 +955,7 @@  static void vmballoon_work(struct work_struct *work)
 	if (b->reset_required)
 		vmballoon_reset(b);
 
-	if (vmballoon_send_get_target(b))
+	if (!vmballoon_send_get_target(b))
 		change = vmballoon_change(b);
 
 	if (change != 0) {