qemu/include/sysemu
Nicolas Saenz Julienne 71ad4713cc util/event-loop-base: Introduce options to set the thread pool size
The thread pool regulates itself: when idle, it kills threads until
empty, when in demand, it creates new threads until full. This behaviour
doesn't play well with latency sensitive workloads where the price of
creating a new thread is too high. For example, when paired with qemu's
'-mlock', or using safety features like SafeStack, creating a new thread
has been measured take multiple milliseconds.

In order to mitigate this let's introduce a new 'EventLoopBase'
property to set the thread pool size. The threads will be created during
the pool's initialization or upon updating the property's value, remain
available during its lifetime regardless of demand, and destroyed upon
freeing it. A properly characterized workload will then be able to
configure the pool to avoid any latency spikes.

Signed-off-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Acked-by: Markus Armbruster <armbru@redhat.com>
Message-id: 20220425075723.20019-4-nsaenzju@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2022-05-09 10:43:23 +01:00
..
accel-ops.h whpx: Added support for breakpoints and stepping 2022-04-06 14:31:55 +02:00
arch_init.h softmmu: Add qemu_init_arch_modules() 2022-03-06 13:15:42 +01:00
balloon.h qapi: Restrict balloon-related commands to machine code 2020-09-29 15:41:35 +02:00
block-backend-common.h block-backend-common.h: split function pointers in BlockDevOps 2022-03-04 18:18:26 +01:00
block-backend-global-state.h include/sysemu/block-backend: split header into I/O and global state (GS) API 2022-03-04 18:18:25 +01:00
block-backend-io.h IO_CODE and IO_OR_GS_CODE for block-backend I/O API 2022-03-04 18:18:25 +01:00
block-backend.h include/sysemu/block-backend: split header into I/O and global state (GS) API 2022-03-04 18:18:25 +01:00
blockdev.h include/sysemu/blockdev.h: global state API 2022-03-04 18:18:25 +01:00
cpu-throttle.h cpu-throttle: new module, extracted from cpus.c 2020-07-10 18:04:49 -04:00
cpu-timers.h cpus: prepare new CpusAccel cpu accelerator interface 2020-10-05 16:41:22 +02:00
cpus.h softmmu: List CPU types again 2022-03-16 08:43:10 +01:00
cryptodev-vhost-user.h cryptodev: Fix Lesser GPL version number 2020-10-27 16:48:49 +01:00
cryptodev-vhost.h cryptodev: Fix Lesser GPL version number 2020-10-27 16:48:49 +01:00
cryptodev.h cryptodev: Fix Lesser GPL version number 2020-10-27 16:48:49 +01:00
device_tree.h device_tree: Add qemu_fdt_add_path 2021-10-20 18:17:54 -07:00
dma.h hw/dma: Let dma_buf_read() / dma_buf_write() propagate MemTxResult 2022-01-18 12:56:29 +01:00
dump-arch.h dump: allow target to set the physical base 2016-01-15 14:40:25 +00:00
dump.h dump: Add more offset variables 2022-04-22 13:36:04 +04:00
event-loop-base.h util/event-loop-base: Introduce options to set the thread pool size 2022-05-09 10:43:23 +01:00
hax.h accel/hax: Introduce CONFIG_HAX_IS_POSSIBLE 2022-03-06 13:15:42 +01:00
hostmem.h hostmem: Wire up RAM_NORESERVE via "reserve" property 2021-06-15 20:27:38 +02:00
hvf_int.h arm/hvf: Add a WFI handler 2021-09-21 16:28:26 +01:00
hvf.h include/sysemu: Poison all accelerator CONFIG switches in common code 2021-05-14 12:31:44 +02:00
hw_accel.h accel: Introduce AccelOpsClass::cpus_are_resettable() 2022-03-06 13:15:42 +01:00
iothread.h Introduce event-loop-base abstract class 2022-05-09 10:43:23 +01:00
kvm_int.h memory: Name all the memory listeners 2021-09-30 15:30:24 +02:00
kvm.h kvm/msi: do explicit commit when adding msi routes 2022-03-15 11:26:20 +01:00
memory_mapping.h sysemu/memory_mapping: Become target-agnostic 2022-03-06 13:15:42 +01:00
numa.h numa: drop support for '-numa node' (without memory specified) 2020-09-30 19:09:20 +02:00
nvmm.h Only check CONFIG_NVMM when NEED_CPU_H is defined 2021-09-13 13:56:26 +02:00
os-posix.h block: move fcntl_setfl() 2022-05-03 15:17:53 +04:00
os-win32.h sysemu/os-win32: Test for and use _lock_file/_unlock_file 2022-04-20 10:51:11 -07:00
qtest.h cpu-timers, icount: new modules 2020-10-05 16:41:22 +02:00
replay.h replay: fix icount request when replaying clock access 2021-02-16 17:15:39 +01:00
reset.h hw: move reset handlers from vl.c to hw/core 2017-01-16 17:52:35 +01:00
rng-random.h Use OBJECT_DECLARE_SIMPLE_TYPE when possible 2020-09-18 14:12:32 -04:00
rng.h qom: Remove module_obj_name parameter from OBJECT_DECLARE* macros 2020-09-18 14:12:32 -04:00
rtc.h rtc: Move RTC function prototypes to their own header 2022-01-28 14:29:46 +00:00
runstate-action.h vl: Add option to avoid stopping VM upon guest panic 2020-12-15 12:51:58 -05:00
runstate.h whpx: Added support for breakpoints and stepping 2022-04-06 14:31:55 +02:00
seccomp.h sandbox: disable -sandbox if CONFIG_SECCOMP undefined 2018-06-01 13:44:15 +02:00
sysemu.h include: move qemu_get_vm_name() to sysemu.h 2022-04-06 14:31:43 +02:00
tcg.h accel/tcg: Merge tcg_exec_init into tcg_init_machine 2021-06-11 09:26:28 -07:00
tpm_backend.h sysemu: Make TPM structures inaccessible if CONFIG_TPM is not defined 2021-06-15 10:55:12 -04:00
tpm_util.h tpm: Fix Lesser GPL version number 2020-11-15 16:44:18 +01:00
tpm.h sysemu: tpm: Add a stub function for TPM_IS_CRB 2022-05-06 09:06:50 -06:00
vhost-user-backend.h qom: Remove module_obj_name parameter from OBJECT_DECLARE* macros 2020-09-18 14:12:32 -04:00
watchdog.h watchdog: remove select_watchdog_action 2021-11-02 15:57:27 +01:00
whpx.h include/sysemu: Poison all accelerator CONFIG switches in common code 2021-05-14 12:31:44 +02:00
xen-mapcache.h include: Make headers more self-contained 2019-08-16 13:31:51 +02:00
xen.h sysemu/xen: Add missing 'exec/cpu-common.h' header for ram_addr_t type 2020-09-30 19:11:36 +02:00