From e6a7d7f71b17e0a44e2155bdad47eae7b5368503 Mon Sep 17 00:00:00 2001 From: David Howells Date: Mon, 30 Oct 2023 11:53:16 +0000 Subject: [PATCH] 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 cc: Marc Dionne cc: linux-afs@lists.infradead.org --- fs/afs/internal.h | 1 + fs/afs/vl_list.c | 2 ++ fs/afs/vl_probe.c | 20 ++++++++++++++++++-- include/trace/events/afs.h | 34 ++++++++++++++++++++++++++++++++++ 4 files changed, 55 insertions(+), 2 deletions(-) diff --git a/fs/afs/internal.h b/fs/afs/internal.h index 9a1e151e77e7..88db04220773 100644 --- a/fs/afs/internal.h +++ b/fs/afs/internal.h @@ -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; diff --git a/fs/afs/vl_list.c b/fs/afs/vl_list.c index 5c4cd71caccf..9b1c20daac53 100644 --- a/fs/afs/vl_list.c +++ b/fs/afs/vl_list.c @@ -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; diff --git a/fs/afs/vl_probe.c b/fs/afs/vl_probe.c index f868ae5d40e5..b128dc3d8af7 100644 --- a/fs/afs/vl_probe.c +++ b/fs/afs/vl_probe.c @@ -131,6 +131,7 @@ responded: 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)) { diff --git a/include/trace/events/afs.h b/include/trace/events/afs.h index 81eb87fbcfa7..f1815b3dafb0 100644 --- a/include/trace/events/afs.h +++ b/include/trace/events/afs.h @@ -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 */