| Message ID | 1604666522-545580-1-git-send-email-andrey.shinkevich@virtuozzo.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | Increase amount of data for monitor to read | expand |
Please exclude this address when reply: jcody@redhat.com Andrey
06.11.2020 15:42, 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 little parser is introduced to throttle JSON commands read from the > buffer so that QMP requests do not overwhelm the monitor input 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"'. > Hi! I tried the following test: start qemu: ./qemu-system-x86_64 -qmp stdio type the following in one line: { 'execute': 'qmp_capabilities' }{ 'execute': 'quit' } press Enter. Without your patches, the qemu quits immediately, printing double "{"return": {}}". With your patches applied qemu prints "{"return": {}}" only once and doesn't quit, until I press Enter the second time. > Andrey Shinkevich (2): > iotests: add another bash sleep command to 247 > monitor: increase amount of data for monitor to read > > chardev/char-fd.c | 64 +++++++++++++++++++++++++++++++++++++++++++++- > chardev/char-socket.c | 54 +++++++++++++++++++++++++++----------- > chardev/char.c | 40 +++++++++++++++++++++++++++++ > include/chardev/char.h | 15 +++++++++++ > monitor/monitor.c | 2 +- > tests/qemu-iotests/247 | 2 ++ > tests/qemu-iotests/247.out | 1 + > 7 files changed, 161 insertions(+), 17 deletions(-) >
09.11.2020 11:50, Vladimir Sementsov-Ogievskiy wrote: > 06.11.2020 15:42, 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 little parser is introduced to throttle JSON commands read from the >> buffer so that QMP requests do not overwhelm the monitor input 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"'. >> > > Hi! > > I tried the following test: > > start qemu: > > ./qemu-system-x86_64 -qmp stdio > > type the following in one line: > > { 'execute': 'qmp_capabilities' }{ 'execute': 'quit' } > > press Enter. > > Without your patches, the qemu quits immediately, printing double "{"return": {}}". > With your patches applied qemu prints "{"return": {}}" only once and doesn't quit, until I press Enter the second time. Positive thing: the patches do increase performance: for me, the following command: (echo "{ 'execute': 'qmp_capabilities' }"; for i in {1..10000}; do echo "{ 'execute': 'query-block-jobs' }"; done; echo "{ 'execute': 'quit' }" ) | time ./qemu-system-x86_64 -qmp stdio > /dev/null shows 2.4s on master and 0.6s after patches > > >> Andrey Shinkevich (2): >> iotests: add another bash sleep command to 247 >> monitor: increase amount of data for monitor to read >> >> chardev/char-fd.c | 64 +++++++++++++++++++++++++++++++++++++++++++++- >> chardev/char-socket.c | 54 +++++++++++++++++++++++++++----------- >> chardev/char.c | 40 +++++++++++++++++++++++++++++ >> include/chardev/char.h | 15 +++++++++++ >> monitor/monitor.c | 2 +- >> tests/qemu-iotests/247 | 2 ++ >> tests/qemu-iotests/247.out | 1 + >> 7 files changed, 161 insertions(+), 17 deletions(-) >> > >
On 09.11.2020 13:04, Vladimir Sementsov-Ogievskiy wrote: > 09.11.2020 11:50, Vladimir Sementsov-Ogievskiy wrote: >> 06.11.2020 15:42, 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 little parser is introduced to throttle JSON commands read from the >>> buffer so that QMP requests do not overwhelm the monitor input 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"'. >>> [...] > > > Positive thing: the patches do increase performance: > > for me, the following command: > > (echo "{ 'execute': 'qmp_capabilities' }"; for i in {1..10000}; do echo > "{ 'execute': 'query-block-jobs' }"; done; echo "{ 'execute': 'quit' }" > ) | time ./qemu-system-x86_64 -qmp stdio > /dev/null > > shows 2.4s on master and 0.6s after patches > > Thank you for testing it. I'd like to include the result to the patch description with "Tested-by: ..." Andrey