SUNRPC: receive buffer size estimation values almost never change

Avoid unnecessary cache sloshing by placing the buffer size
estimation update logic behind an atomic bit flag.

The size of GSS information included in each wrapped Reply does
not change during the lifetime of a GSS context. Therefore, the
au_rslack and au_ralign fields need to be updated only once after
establishing a fresh GSS credential.

Thus a slack size update must occur after a cred is created,
duplicated, renewed, or expires. I'm not sure I have this exactly
right. A trace point is introduced to track updates to these
variables to enable troubleshooting the problem if I missed a spot.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
This commit is contained in:
Chuck Lever
2020-05-12 17:13:01 -04:00
committed by Anna Schumaker
parent ef31d878b2
commit 53bc19f17f
4 changed files with 69 additions and 18 deletions

View File

@@ -291,6 +291,40 @@ TRACE_EVENT(rpcgss_need_reencode,
__entry->ret ? "" : "un")
);
TRACE_EVENT(rpcgss_update_slack,
TP_PROTO(
const struct rpc_task *task,
const struct rpc_auth *auth
),
TP_ARGS(task, auth),
TP_STRUCT__entry(
__field(unsigned int, task_id)
__field(unsigned int, client_id)
__field(u32, xid)
__field(const void *, auth)
__field(unsigned int, rslack)
__field(unsigned int, ralign)
__field(unsigned int, verfsize)
),
TP_fast_assign(
__entry->task_id = task->tk_pid;
__entry->client_id = task->tk_client->cl_clid;
__entry->xid = be32_to_cpu(task->tk_rqstp->rq_xid);
__entry->auth = auth;
__entry->rslack = auth->au_rslack;
__entry->ralign = auth->au_ralign;
__entry->verfsize = auth->au_verfsize;
),
TP_printk("task:%u@%u xid=0x%08x auth=%p rslack=%u ralign=%u verfsize=%u\n",
__entry->task_id, __entry->client_id, __entry->xid,
__entry->auth, __entry->rslack, __entry->ralign,
__entry->verfsize)
);
DECLARE_EVENT_CLASS(rpcgss_svc_seqno_class,
TP_PROTO(
__be32 xid,