Re: [PATCH v5 3/4] apparmor: experiment with faster backoff on global buffer

[John Johansen]

Instead of doubling hold count when contention is encounter increase
it by 8x. This makes for a faster back off, but results in buffers
being held longer.

Signed-off-by: John Johansen <john.johansen@xxxxxxxxxxxxx>
---
 security/apparmor/lsm.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
index fd6779ff0da4..52423d88854a 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -1796,10 +1796,10 @@ static int param_set_mode(const char *val, const struct kernel_param *kp)
 
 static void update_contention(struct aa_local_cache *cache)
 {
-	cache->contention += 1;
+	cache->contention += 3;
 	if (cache->contention > 9)
 		cache->contention = 9;
-	cache->hold += 1 << cache->contention;		/* 2, 4, 8, ... */
+	cache->hold += 1 << cache->contention;		/* 8, 64, 512, ... */
 }
 
 char *aa_get_buffer(bool in_atomic)
--
2.34.1