| Message ID | 20220316135321.142850-1-nsaenzju@redhat.com |
|---|---|
| Headers | show |
| Series | util/thread-pool: Expose minimun and maximum size | expand |
On Wed, Mar 16, 2022 at 02:53:20PM +0100, Nicolas Saenz Julienne wrote: > As discussed on the previous RFC[1] the thread-pool's dynamic thread > management doesn't play well with real-time and latency sensitive > systems. This series introduces a set of controls that'll permit > achieving more deterministic behaviours, for example by fixing the > pool's size. > > We first introduce a new common interface to event loop configuration by > moving iothread's already available properties into an abstract class > called 'EventLooopBackend' and have both 'IOThread' and the newly > created 'MainLoop' inherit the properties from that class. > > With this new configuration interface in place it's relatively simple to > introduce new options to fix the even loop's thread pool sizes. The > resulting QAPI looks like this: > > -object main-loop,id=main-loop,thread-pool-min=1,thread-pool-max=1 > > Note that all patches are bisect friendly and pass all the tests. > > [1] https://patchwork.ozlabs.org/project/qemu-devel/patch/20220202175234.656711-1-nsaenzju@redhat.com/ > > --- > Changes since v2: > - Get rid of wrong locking/waiting > - Fix qapi versioning > - Better commit messages > > Changes since v1: > - Address all Stefan's comments > - Introduce new fix > > Nicolas Saenz Julienne (3): > Introduce event-loop-base abstract class > util/main-loop: Introduce the main loop into QOM > util/event-loop-base: Introduce options to set the thread pool size > > event-loop-base.c | 140 +++++++++++++++++++++++++++++++ > include/block/aio.h | 10 +++ > include/block/thread-pool.h | 3 + > include/qemu/main-loop.h | 10 +++ > include/sysemu/event-loop-base.h | 41 +++++++++ > include/sysemu/iothread.h | 6 +- > iothread.c | 68 +++++---------- > meson.build | 26 +++--- > qapi/qom.json | 34 +++++++- > util/aio-posix.c | 1 + > util/async.c | 20 +++++ > util/main-loop.c | 65 ++++++++++++++ > util/thread-pool.c | 55 +++++++++++- > 13 files changed, 414 insertions(+), 65 deletions(-) > create mode 100644 event-loop-base.c > create mode 100644 include/sysemu/event-loop-base.h > > -- > 2.35.1 > Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
As discussed on the previous RFC[1] the thread-pool's dynamic thread management doesn't play well with real-time and latency sensitive systems. This series introduces a set of controls that'll permit achieving more deterministic behaviours, for example by fixing the pool's size. We first introduce a new common interface to event loop configuration by moving iothread's already available properties into an abstract class called 'EventLooopBackend' and have both 'IOThread' and the newly created 'MainLoop' inherit the properties from that class. With this new configuration interface in place it's relatively simple to introduce new options to fix the even loop's thread pool sizes. The resulting QAPI looks like this: -object main-loop,id=main-loop,thread-pool-min=1,thread-pool-max=1 Note that all patches are bisect friendly and pass all the tests. [1] https://patchwork.ozlabs.org/project/qemu-devel/patch/20220202175234.656711-1-nsaenzju@redhat.com/ --- Changes since v2: - Get rid of wrong locking/waiting - Fix qapi versioning - Better commit messages Changes since v1: - Address all Stefan's comments - Introduce new fix Nicolas Saenz Julienne (3): Introduce event-loop-base abstract class util/main-loop: Introduce the main loop into QOM util/event-loop-base: Introduce options to set the thread pool size event-loop-base.c | 140 +++++++++++++++++++++++++++++++ include/block/aio.h | 10 +++ include/block/thread-pool.h | 3 + include/qemu/main-loop.h | 10 +++ include/sysemu/event-loop-base.h | 41 +++++++++ include/sysemu/iothread.h | 6 +- iothread.c | 68 +++++---------- meson.build | 26 +++--- qapi/qom.json | 34 +++++++- util/aio-posix.c | 1 + util/async.c | 20 +++++ util/main-loop.c | 65 ++++++++++++++ util/thread-pool.c | 55 +++++++++++- 13 files changed, 414 insertions(+), 65 deletions(-) create mode 100644 event-loop-base.c create mode 100644 include/sysemu/event-loop-base.h