On 23.11.2020 18:44, Andrey Shinkevich wrote:
The subject was discussed here:
https://lists.gnu.org/archive/html/qemu-devel/2017-05/msg00206.html
This series is a solution for the issue with QMP monitor buffered input.
A JSON little parser is introduced to separate QMP commands read from the
input buffer so that incoming requests do not overwhelm the monitor queue.
A side effect raised in the test #247 was managed in the first patch.
It may be considered as a workaround. Any sane fix suggested will be
appreciated.
Note:
This series goes after the Vladimir's one:
'[PATCH v3 00/25] backup performance: block_status + async"'
To make the test #129 passed, the following patch should be applied first:
'[PATCH v3 01/25] iotests: 129 don't check backup "busy"'.
v2:
02: The static JSONthrottle object was made a member of the Chardev
structure.
The fd_chr_read functions were merged.
The monitor thread synchronization was added to protect the input queue
from overflow.
Andrey Shinkevich (2):
iotests: add another bash sleep command to 247
monitor: increase amount of data for monitor to read
chardev/char-fd.c | 35 +++++++++++++++++++++++++++++++++--
chardev/char-socket.c | 42 +++++++++++++++++++++++++++++++++++++++---
chardev/char.c | 41 +++++++++++++++++++++++++++++++++++++++++
include/chardev/char.h | 15 +++++++++++++++
monitor/monitor.c | 2 +-
tests/qemu-iotests/247 | 2 ++
tests/qemu-iotests/247.out | 1 +
7 files changed, 132 insertions(+), 6 deletions(-)
The Vladimir's modified test case
$ time (echo "{ 'execute': 'qmp_capabilities' }"; for i in {1..10000};
do echo "{ 'execute': 'query-block-jobs' } {"execute":"query-status"} {
'execute': 'query-block-jobs' } {"execute":"query-status"}"; done; echo
"{ 'execute': 'quit' }" ) | ./build/qemu-system-x86_64 -qmp stdio >
/dev/null
shows the following performance
on master:
real 0m5.188s
user 0m5.310s
sys 0m2.539s
after the patch applied:
real 0m2.227s
user 0m2.483s
sys 0m0.480s
Andrey
