diff mbox series

[9/9] hw/9pfs/9p.c: benchmark time on T_readdir request

Message ID E1ihMvZ-000797-2Q@lizzy.crudebyte.com
State New
Headers show
Series None | expand

Commit Message

Christian Schoenebeck Dec. 17, 2019, 10 p.m. UTC 
This patch is not intended to be merged, it measures
and prints the time the 9p server spends on handling
a T_readdir request. It prints the total time it spent
on handling the request, and also the time it spent
on IO (driver) only.

Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
---
 hw/9pfs/9p.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)
diff mbox series

Patch

diff --git a/hw/9pfs/9p.c b/hw/9pfs/9p.c
index b37f979150..68ce104d7e 100644
--- a/hw/9pfs/9p.c
+++ b/hw/9pfs/9p.c
@@ -2301,6 +2301,14 @@  static void v9fs_free_dirents(struct V9fsDirEnt *e)
     }
 }
 
+static double wall_time(void) {
+    struct timeval t;
+    struct timezone tz;
+    gettimeofday(&t, &tz);
+    return t.tv_sec + t.tv_usec * 0.000001;
+}
+
+
 static int coroutine_fn v9fs_do_readdir(V9fsPDU *pdu, V9fsFidState *fidp,
                                         int32_t max_count)
 {
@@ -2320,6 +2328,8 @@  static int coroutine_fn v9fs_do_readdir(V9fsPDU *pdu, V9fsFidState *fidp,
      */
     const bool dostat = pdu->s->ctx.export_flags & V9FS_REMAP_INODES;
 
+    const double start = wall_time();
+
     /*
      * Fetch all required directory entries altogether on a background IO
      * thread from fs driver. We don't want to do that for each entry
@@ -2334,6 +2344,9 @@  static int coroutine_fn v9fs_do_readdir(V9fsPDU *pdu, V9fsFidState *fidp,
     }
     count = 0;
 
+    const double end = wall_time();
+    printf("\n\nTime 9p server spent on synth_readdir() I/O only (synth driver): %fs\n", end - start);
+
     for (struct V9fsDirEnt* e = entries; e; e = e->next) {
         dent = e->dent;
 
@@ -2406,6 +2419,8 @@  static void coroutine_fn v9fs_readdir(void *opaque)
     V9fsPDU *pdu = opaque;
     V9fsState *s = pdu->s;
 
+    const double start = wall_time();
+
     retval = pdu_unmarshal(pdu, offset, "dqd", &fid,
                            &initial_offset, &max_count);
     if (retval < 0) {
@@ -2449,6 +2464,9 @@  out:
     put_fid(pdu, fidp);
 out_nofid:
     pdu_complete(pdu, retval);
+
+    const double end = wall_time();
+    printf("Time 9p server spent on entire T_readdir request: %fs [IMPORTANT]\n", end - start);
 }
 
 static int v9fs_xattr_write(V9fsState *s, V9fsPDU *pdu, V9fsFidState *fidp,