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| author | Simon Rettberg | 2013-10-24 15:37:26 +0200 |
|---|---|---|
| committer | Simon Rettberg | 2013-10-24 15:37:26 +0200 |
| commit | 897a3127e05a3841abc30edbb354d92b54e60b8d (patch) | |
| tree | 452553ce4c17b9523e8d65fe1aa474ad2a142b07 | |
| parent | [SERVER] Refactoring, more debug output, try to check for cyclic proxying (diff) | |
| download | dnbd3-897a3127e05a3841abc30edbb354d92b54e60b8d.tar.gz dnbd3-897a3127e05a3841abc30edbb354d92b54e60b8d.tar.xz dnbd3-897a3127e05a3841abc30edbb354d92b54e60b8d.zip | |
[KERNEL] Detect stale state and change server
| -rw-r--r-- | src/kernel/net.c | 27 |
1 files changed, 24 insertions, 3 deletions
diff --git a/src/kernel/net.c b/src/kernel/net.c index bb41ce3..b3e08df 100644 --- a/src/kernel/net.c +++ b/src/kernel/net.c @@ -438,9 +438,11 @@ int dnbd3_net_discover(void *data) unsigned long irqflags; int i, best_server, current_server; int turn = 0; - int ready = 0; + int ready = 0, do_change; int mlen; + struct request *last_request = (struct request *)123, *cur_request = (struct request *)456; + struct timeval timeout; timeout.tv_sec = SOCKET_TIMEOUT_CLIENT_DISCOVERY; timeout.tv_usec = 0; @@ -739,9 +741,28 @@ int dnbd3_net_discover(void *data) continue; } + do_change = !dev->is_server && ready && best_server != current_server && (jiffies & 3) != 0 + && RTT_THRESHOLD_FACTOR(dev->cur_rtt) > best_rtt; + + if (ready && !do_change) { + spin_lock_irqsave(&dev->blk_lock, irqflags); + if (!list_empty(&dev->request_queue_send)) + { + cur_request = list_entry(dev->request_queue_send.next, struct request, queuelist); + do_change = (cur_request == last_request); + if (do_change) + printk("WARNING: Hung request on %s\n", dev->disk->disk_name); + } + else + { + cur_request = (struct request *)123; + } + last_request = cur_request; + spin_unlock_irqrestore(&dev->blk_lock, irqflags); + } + // take server with lowest rtt (only if in client mode) - if (!dev->is_server && ready && best_server != current_server && (jiffies & 3) != 0 - && RTT_THRESHOLD_FACTOR(dev->cur_rtt) > best_rtt) + if (do_change) { printk("INFO: Server %d on %s is faster (%lluµs vs. %lluµs)\n", best_server, dev->disk->disk_name, (unsigned long long)best_rtt, (unsigned long long)dev->cur_rtt); |