afs: Dispatch vlserver probes in priority order

When probing all the addresses for a volume location server, dispatch them
in order of descending priority to try and get back highest priority one
first.

Also add a tracepoint to show the transmission and completion of the
probes.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
This commit is contained in:
David Howells 2023-10-30 11:53:16 +00:00
parent 92f091cddd
commit e6a7d7f71b
4 changed files with 55 additions and 2 deletions

View File

@ -447,6 +447,7 @@ struct afs_vlserver {
rwlock_t lock; /* Lock on addresses */
refcount_t ref;
unsigned int rtt; /* Server's current RTT in uS */
unsigned int debug_id;
/* Probe state */
wait_queue_head_t probe_wq;

View File

@ -13,6 +13,7 @@ struct afs_vlserver *afs_alloc_vlserver(const char *name, size_t name_len,
unsigned short port)
{
struct afs_vlserver *vlserver;
static atomic_t debug_ids;
vlserver = kzalloc(struct_size(vlserver, name, name_len + 1),
GFP_KERNEL);
@ -21,6 +22,7 @@ struct afs_vlserver *afs_alloc_vlserver(const char *name, size_t name_len,
rwlock_init(&vlserver->lock);
init_waitqueue_head(&vlserver->probe_wq);
spin_lock_init(&vlserver->probe_lock);
vlserver->debug_id = atomic_inc_return(&debug_ids);
vlserver->rtt = UINT_MAX;
vlserver->name_len = name_len;
vlserver->service_id = VL_SERVICE;

View File

@ -131,6 +131,7 @@ void afs_vlserver_probe_result(struct afs_call *call)
out:
spin_unlock(&server->probe_lock);
trace_afs_vl_probe(server, false, alist, index, call->error, call->abort_code, rtt_us);
_debug("probe [%u][%u] %pISpc rtt=%d ret=%d",
server_index, index, rxrpc_kernel_remote_addr(addr->peer),
rtt_us, ret);
@ -150,8 +151,10 @@ static bool afs_do_probe_vlserver(struct afs_net *net,
{
struct afs_addr_list *alist;
struct afs_call *call;
unsigned int index;
unsigned long unprobed;
unsigned int index, i;
bool in_progress = false;
int best_prio;
_enter("%s", server->name);
@ -165,7 +168,20 @@ static bool afs_do_probe_vlserver(struct afs_net *net,
memset(&server->probe, 0, sizeof(server->probe));
server->probe.rtt = UINT_MAX;
for (index = 0; index < alist->nr_addrs; index++) {
unprobed = (1UL << alist->nr_addrs) - 1;
while (unprobed) {
best_prio = -1;
index = 0;
for (i = 0; i < alist->nr_addrs; i++) {
if (test_bit(i, &unprobed) &&
alist->addrs[i].prio > best_prio) {
index = i;
best_prio = alist->addrs[i].prio;
}
}
__clear_bit(index, &unprobed);
trace_afs_vl_probe(server, true, alist, index, 0, 0, 0);
call = afs_vl_get_capabilities(net, alist, index, key, server,
server_index);
if (!IS_ERR(call)) {

View File

@ -1420,6 +1420,40 @@ TRACE_EVENT(afs_fs_probe,
&__entry->srx.transport)
);
TRACE_EVENT(afs_vl_probe,
TP_PROTO(struct afs_vlserver *server, bool tx, struct afs_addr_list *alist,
unsigned int addr_index, int error, s32 abort_code, unsigned int rtt_us),
TP_ARGS(server, tx, alist, addr_index, error, abort_code, rtt_us),
TP_STRUCT__entry(
__field(unsigned int, server)
__field(bool, tx)
__field(unsigned short, flags)
__field(u16, addr_index)
__field(short, error)
__field(s32, abort_code)
__field(unsigned int, rtt_us)
__field_struct(struct sockaddr_rxrpc, srx)
),
TP_fast_assign(
__entry->server = server->debug_id;
__entry->tx = tx;
__entry->addr_index = addr_index;
__entry->error = error;
__entry->abort_code = abort_code;
__entry->rtt_us = rtt_us;
memcpy(&__entry->srx, rxrpc_kernel_remote_srx(alist->addrs[addr_index].peer),
sizeof(__entry->srx));
),
TP_printk("vl=%08x %s ax=%u e=%d ac=%d rtt=%d %pISpc",
__entry->server, __entry->tx ? "tx" : "rx", __entry->addr_index,
__entry->error, __entry->abort_code, __entry->rtt_us,
&__entry->srx.transport)
);
#endif /* _TRACE_AFS_H */
/* This part must be outside protection */