WBThrottle: make bytes/ios/inode_wb's perf counter effective

Since sync thread will cause unstable iops and latency performance curve, we
may want make WBThread do more(or moderate?) writeback and avoid sync thread
flush too much which will cause journal io long tail.

Via these counters, we can view how much object or bytes are write backed by
WBThread and how much bytes are flushed . Then we can have a great tuning for
"*bytes_start_flusher", "*ios_start_flusher" and "*inodes_start_flusher".
What we want to see is that in-memory data can writeback into disk with a
moderate rate.

Signed-off-by: Haomai Wang <haomaiwang@gmail.com>

diff --git a/src/os/WBThrottle.cc b/src/os/WBThrottle.cc
index 7d0bcf6f45f2169cc34855e98522940fc4e6983b..27a23001794e2dae75d2b3affd166dfec07a385b 100644 (file)
--- a/src/os/WBThrottle.cc
+++ b/src/os/WBThrottle.cc
@@ -175,9 +175,12 @@ void *WBThrottle::entry()
     clearing = ghobject_t();
     cur_ios -= wb.get<2>().ios;
     logger->dec(l_wbthrottle_ios_dirtied, wb.get<2>().ios);
+    logger->inc(l_wbthrottle_ios_wb, wb.get<2>().ios);
     cur_size -= wb.get<2>().size;
     logger->dec(l_wbthrottle_bytes_dirtied, wb.get<2>().size);
+    logger->inc(l_wbthrottle_bytes_wb, wb.get<2>().size);
     logger->dec(l_wbthrottle_inodes_dirtied);
+    logger->inc(l_wbthrottle_inodes_wb);
     cond.Signal();
     wb = boost::tuple<ghobject_t, FDRef, PendingWB>();
   }