qemu/include
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
..
authz Prefer 'on' | 'off' over 'yes' | 'no' for bool options 2021-01-29 17:07:53 +00:00
block util/event-loop-base: Introduce options to set the thread pool size 2022-05-09 10:43:23 +01:00
chardev Replace GCC_FMT_ATTR with G_GNUC_PRINTF 2022-03-22 14:40:51 +04:00
crypto crypto: move sm4_sbox from target/arm 2022-04-29 10:47:45 +10:00
disas disas: Remove old libopcode s390 disassembler 2022-05-04 08:47:19 +02:00
exec compiler.h: replace QEMU_NORETURN with G_NORETURN 2022-04-21 17:03:51 +04:00
fpu softfloat: add float128_to_int128 2022-04-20 18:00:30 -03:00
hw lasi: move from hw/hppa to hw/misc 2022-05-08 18:52:37 +01:00
io io: make qio_channel_command_new_pid() static 2022-05-03 15:47:59 +04:00
libdecnumber Replace config-time define HOST_WORDS_BIGENDIAN 2022-04-06 10:50:37 +02:00
migration migration: Remove load_state_old and minimum_version_id_old 2022-03-02 18:20:45 +00:00
monitor Move error_printf_unless_qmp() with monitor unit 2022-04-21 17:09:09 +04:00
net Replace config-time define HOST_WORDS_BIGENDIAN 2022-04-06 10:50:37 +02:00
qapi include: move qdict_{crumple,flatten} declarations 2022-04-21 17:03:51 +04:00
qemu util/main-loop: Introduce the main loop into QOM 2022-05-09 10:43:23 +01:00
qom compiler.h: replace QEMU_SENTINEL with G_GNUC_NULL_TERMINATED 2022-03-22 14:40:51 +04:00
scsi scsi: inline sg_io_sense_from_errno() into the callers. 2021-03-06 11:42:56 +01:00
semihosting semihosting: Move include/hw/semihosting/ -> include/semihosting/ 2021-03-10 15:34:12 +00:00
standard-headers headers: Add pvpanic.h 2022-03-06 05:08:23 -05:00
sysemu util/event-loop-base: Introduce options to set the thread pool size 2022-05-09 10:43:23 +01:00
tcg tcg: Implement tcg_gen_{h,w}swap_{i32,i64} 2022-05-04 08:47:19 +02:00
ui qapi/ui: add 'display-update' command for changing listen address 2022-04-27 07:51:01 +02:00
user common-user: Move safe-syscall.* from linux-user 2021-12-20 10:12:24 -08:00
elf.h elf: Add machine type value for LoongArch 2021-12-21 13:17:06 -08:00
glib-compat.h compiler.h: replace QEMU_NORETURN with G_NORETURN 2022-04-21 17:03:51 +04:00
qemu-io.h Include qemu-common.h exactly where needed 2019-06-12 13:20:20 +02:00
qemu-main.h Simplify softmmu/main.c 2022-04-21 16:56:55 +04:00