[Qemu-devel] [PATCH v2 0/9] synchronization profiler

[Emilio G. Cota]

v1: https://lists.gnu.org/archive/html/qemu-devel/2018-08/msg02186.html

Changes since v1:

- Rebase on current master.
- Update copyright to 2018.
- Add -m option to the HMP info command to sort by average wait time,
  as suggested by Paolo.
- Add -n option to the HMP info command to NOT merge call sites.
  The default does merge call sites, as suggested by Paolo (thanks
  to Peter for the clarification).
- Switch to camel case in qsp.c
- Update the commit logs of the two HMP patches to clearly state
  that this is only for developers, so it is HMP-only.
- Rename the HMP command from "sync" to "sync-profile", as suggested
  by Markus.
- Use int for line info consistently (was using unsigned sometimes)
- Drop qsp_init from qsp_cond_wait, as suggested by Fam.
- #undef QSP_GEN_{VOID,RET1} once they're no longer used.
- Add qsp_reset()
  This uses a snapshot to avoid deleting items, which would require
  adding rcu_read_lock/unlock to the fast path.
- Convert to run-time option, as suggested by Fam
  - Add -enable-sync-profile to qemu-options
  - Add sync-profile HMP command: "sync-profile on|off|reset"
- allocate QSPEntry with g_new0

I added most new bits as separate patches to ease review.

The first patch has some perf numbers; the last patch shows
sample output from the monitor.

Checkpatch gives some errors, but they're false positives.

You can fetch this series from:
  https://github.com/cota/qemu/tree/sync-profiler-v2

Diffstat below.

Thanks,

                Emilio
---
 cpus.c                      |  10 +-
 hmp-commands-info.hx        |  22 ++
 hmp-commands.hx             |  15 +
 hmp.c                       |  24 ++
 hmp.h                       |   1 +
 include/qemu/main-loop.h    |   4 +-
 include/qemu/qht.h          |   1 +
 include/qemu/qsp.h          |  29 ++
 include/qemu/thread-posix.h |   4 +-
 include/qemu/thread-win32.h |   5 +-
 include/qemu/thread.h       |  66 +++-
 monitor.c                   |  11 +
 qemu-options.hx             |  10 +
 stubs/iothread-lock.c       |   2 +-
 tests/atomic_add-bench.c    |   6 +-
 util/Makefile.objs          |   1 +
 util/qemu-thread-win32.c    |   4 +-
 util/qht.c                  |  47 ++-
 util/qsp.c                  | 779 +++++++++++++++++++++++++++++++++++++++
 vl.c                        |   3 +
 20 files changed, 1016 insertions(+), 28 deletions(-)
 create mode 100644 include/qemu/qsp.h
 create mode 100644 util/qsp.c