Re: [PATCH 14/16] conf: Expose QEMU's main loop object

On Thu, Jun 02, 2022 at 01:54:39PM +0200, Peter Krempa wrote: > On Thu, Jun 02, 2022 at 09:18:04 +0200, Michal Privoznik wrote: >> As of v7.0.0-877-g70ac26b9e5 QEMU exposes its main event loop as >> an QMP object. In the very next commit (v7.0.0-878-g71ad4713cc) >> it was extended for thread-pool-min and thread-pool-max >> attributes. Expose them under new <mainloop/> element. >> >> Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com&gt; >> --- >> docs/formatdomain.rst | 5 ++ >> src/conf/domain_conf.c | 57 +++++++++++++++++++ >> src/conf/domain_conf.h | 8 +++ >> src/conf/schemas/domaincommon.rng | 15 +++++ >> src/conf/virconftypes.h | 2 + >> .../iothreads-ids-pool-sizes.xml | 1 + >> 6 files changed, 88 insertions(+) >> >> diff --git a/docs/formatdomain.rst b/docs/formatdomain.rst >> index de085f616a..5e0019c574 100644 >> --- a/docs/formatdomain.rst >> +++ b/docs/formatdomain.rst > > [...] > >> @@ -699,6 +700,10 @@ host/guest with many LUNs. :since:`Since 1.2.8 (QEMU only)` >> The element has two optional attributes ``pool_min`` and ``pool_max`` which >> allow setting lower and upper boundary for number of worker threads for >> given IOThread. :since:`Since 8.4.0` >> +``mainloop`` >> + The optional ``mainloop`` element contains two optional attributes >> + ``pool_min`` and ``pool_max`` which allow setting lower and upper boundary >> + for number of worker threads for the main event loop. :since:`Since 8.4.0` > > I don't think we should use the qemu term "main loop" here. In general > we refer to the qemu process as emulator, including stuff like > emulatorpin and similar. It isn't even especially part of the QEMU main loop IIUC. Rather it is setting up a pool of threads that are used for serving I/O, when no specific I/O thread is configurd for the guest. Perhaps it can be '<defaultiothread/>' or something along those lines, to make it clear it is an I/O related tunable.