qemu/util
bauerchen 037fb5eb39 mem-prealloc: optimize large guest startup
[desc]:
    Large memory VM starts slowly when using -mem-prealloc, and
    there are some areas to optimize in current method;

    1、mmap will be used to alloc threads stack during create page
    clearing threads, and it will attempt mm->mmap_sem for write
    lock, but clearing threads have hold read lock, this competition
    will cause threads createion very slow;

    2、methods of calcuating pages for per threads is not well;if we use
    64 threads to split 160 hugepage,63 threads clear 2page,1 thread
    clear 34 page,so the entire speed is very slow;

    to solve the first problem,we add a mutex in thread function,and
    start all threads when all threads finished createion;
    and the second problem, we spread remainder to other threads,in
    situation that 160 hugepage and 64 threads, there are 32 threads
    clear 3 pages,and 32 threads clear 2 pages.

[test]:
    320G 84c VM start time can be reduced to 10s
    680G 84c VM start time can be reduced to 18s

Signed-off-by: bauerchen <bauerchen@tencent.com>
Reviewed-by: Pan Rui <ruippan@tencent.com>
Reviewed-by: Ivan Ren <ivanren@tencent.com>
[Simplify computation of the number of pages per thread. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-02-25 09:18:01 +01:00
..
aio-posix.c aio-posix: make AioHandler dispatch O(1) with epoll 2020-02-22 08:26:47 +00:00
aio-wait.c block: Use a single global AioWait 2018-09-25 15:50:15 +02:00
aio-win32.c aio-posix: Fix concurrent aio_poll/set_fd_handler. 2019-01-14 14:09:41 +00:00
aiocb.c block: move AioContext, QEMUTimer, main-loop to libqemuutil 2017-02-21 11:14:07 +00:00
async.c util/async: make bh_aio_poll() O(1) 2020-02-22 08:26:47 +00:00
atomic64.c util: add atomic64 2018-10-02 18:47:55 +02:00
base64.c
bitmap.c bitmap: Add bitmap_copy_with_{src|dst}_offset() 2019-07-15 15:39:02 +02:00
bitops.c avoid TABs in files that only contain a few 2019-01-11 15:46:56 +01:00
buffer.c qemu-common: stop including qemu/host-utils.h from qemu-common.h 2016-05-19 16:42:28 +02:00
bufferiszero.c Include qemu-common.h exactly where needed 2019-06-12 13:20:20 +02:00
cacheinfo.c util/cacheinfo: fix crash when compiling with uClibc 2020-01-21 14:18:12 -10:00
compatfd.c Include qemu-common.h exactly where needed 2019-06-12 13:20:20 +02:00
coroutine-sigaltstack.c coroutine-sigaltstack: use helper for allocating stack memory 2016-09-29 14:13:39 +02:00
coroutine-ucontext.c Include qemu-common.h exactly where needed 2019-06-12 13:20:20 +02:00
coroutine-win32.c coroutine: add a macro for the coroutine stack size 2016-09-29 14:13:39 +02:00
crc32c.c Include qemu-common.h exactly where needed 2019-06-12 13:20:20 +02:00
cutils.c util/cutils: Turn FIXME comment into QEMU_BUILD_BUG_ON() 2019-12-18 12:26:25 +01:00
dbus.c util: add dbus helper unit 2020-01-06 18:41:32 +04:00
drm.c util: promote qemu_egl_rendernode_open() to libqemuutil 2018-08-27 10:51:44 +02:00
envlist.c Include qemu-common.h exactly where needed 2019-06-12 13:20:20 +02:00
error.c error: make Error **errp const where it is appropriate 2019-12-18 08:36:16 +01:00
event_notifier-posix.c event_notifier: avoid dandling file descriptor in event_notifier_cleanup 2019-10-24 19:26:52 +02:00
event_notifier-win32.c Revert "qemu: add a cleanup callback function to EventNotifier" 2018-01-24 19:20:19 +02:00
fifo8.c Include migration/vmstate.h less 2019-08-16 13:31:52 +02:00
filemonitor-inotify.c filemon: fix watch IDs to avoid potential wraparound issues 2019-04-02 13:52:02 +01:00
filemonitor-stub.c filemon: fix watch IDs to avoid potential wraparound issues 2019-04-02 13:52:02 +01:00
getauxval.c Include qemu-common.h exactly where needed 2019-06-12 13:20:20 +02:00
guest-random.c replay: record and replay random number sources 2020-01-07 12:08:39 +01:00
hbitmap.c hbitmap: handle set/reset with zero length 2019-10-28 11:22:30 +01:00
hexdump.c
host-utils.c host-utils: Implement unsigned quadword left/right shift and unit tests 2017-01-31 10:10:14 +11:00
id.c chardev: generate an internal id when none given 2020-01-07 16:50:09 +04:00
iov.c util/ioc.c: try to reassure Coverity about qemu_iovec_init_extended 2019-10-08 14:27:35 +01:00
iova-tree.c util: remove redundant include of glib.h and add osdep.h 2018-06-29 12:22:28 +01:00
keyval.c qobject: Replace qobject_incref/QINCREF qobject_decref/QDECREF 2018-05-04 08:27:53 +02:00
lockcnt.c qemu-thread: optimize QemuLockCnt with futexes on Linux 2017-01-16 13:25:18 +00:00
log.c linux-user: Use `qemu_log' for strace 2020-02-19 11:17:40 +01:00
main-loop.c Do not use %m in common code to print error messages 2019-10-22 09:38:42 +02:00
Makefile.objs mem: move nvdimm_device_list to utilities 2020-02-21 09:15:03 +11:00
memfd.c linux-user: add memfd_create 2019-09-11 08:46:17 +02:00
mmap-alloc.c core: replace getpagesize() with qemu_real_host_page_size 2019-10-26 15:38:06 +02:00
module.c module: check module wasn't already initialized 2020-02-22 08:26:47 +00:00
notify.c xen / notify: introduce a new XenWatchList abstraction 2019-09-24 12:18:47 +01:00
nvdimm-utils.c mem: move nvdimm_device_list to utilities 2020-02-21 09:15:03 +11:00
osdep.c osdep: add qemu_unlink() 2020-01-02 16:29:32 +04:00
oslib-posix.c mem-prealloc: optimize large guest startup 2020-02-25 09:18:01 +01:00
oslib-win32.c core: replace getpagesize() with qemu_real_host_page_size 2019-10-26 15:38:06 +02:00
pagesize.c util: move qemu_real_host_page_size/mask to osdep.h 2017-10-10 09:45:00 -07:00
path.c util/path: Do not cache all filenames at startup 2019-06-24 22:19:30 +02:00
qdist.c qdist: return "(empty)" instead of NULL when printing an empty dist 2016-08-03 18:44:56 +02:00
qemu-co-shared-resource.c util: introduce SharedResource 2019-10-28 11:22:31 +01:00
qemu-config.c Include qemu-common.h exactly where needed 2019-06-12 13:20:20 +02:00
qemu-coroutine-io.c yield_until_fd_readable: make it work with any AioContect 2019-10-25 14:38:29 +02:00
qemu-coroutine-lock.c Include qemu-common.h exactly where needed 2019-06-12 13:20:20 +02:00
qemu-coroutine-sleep.c qemu-coroutine-sleep: Silence Coverity warning 2019-11-18 16:01:34 -06:00
qemu-coroutine.c Include qemu-common.h exactly where needed 2019-06-12 13:20:20 +02:00
qemu-error.c error: Fix -msg timestamp default 2019-12-18 08:36:15 +01:00
qemu-openpty.c
qemu-option.c Include qemu-common.h exactly where needed 2019-06-12 13:20:20 +02:00
qemu-print.c qemu-print: New qemu_fprintf(), qemu_vfprintf() 2019-04-18 22:18:59 +02:00
qemu-progress.c progress: Show current progress on SIGINFO 2017-04-28 18:48:11 +02:00
qemu-sockets.c util/qemu-sockets: fix keep_alive handling in inet_connect_saddr 2019-09-25 08:15:44 -05:00
qemu-thread-common.h Clean up includes 2018-12-20 10:29:08 +01:00
qemu-thread-posix.c qemu-thread: Add qemu_cond_timedwait 2019-09-16 17:13:06 +02:00
qemu-thread-win32.c qemu-thread: Add qemu_cond_timedwait 2019-09-16 17:13:06 +02:00
qemu-timer-common.c Remove support for CLOCK_MONOTONIC not being defined 2020-02-12 16:23:01 +01:00
qemu-timer.c qemu-timer: reuse MIN macro in qemu_timeout_ns_to_ms 2019-10-24 20:10:18 +02:00
qht.c qht: constify arguments to some internal functions 2018-09-26 08:55:54 -07:00
qsp.c qsp: Use WITH_RCU_READ_LOCK_GUARD 2019-12-17 19:33:52 +01:00
range.c Don't talk about the LGPL if the file is licensed under the GPL 2019-01-30 10:51:20 +01:00
rcu.c Include qemu-common.h exactly where needed 2019-06-12 13:20:20 +02:00
readline.c qemu-common: Move qemu_isalnum() etc. to qemu/ctype.h 2019-06-11 20:22:09 +02:00
stats64.c util/stats64: Fix min/max comparisons 2017-11-15 09:34:51 +01:00
sys_membarrier.c sys_membarrier: fix up include directives 2018-04-05 14:37:38 +02:00
systemd.c Do not use %m in common code to print error messages 2019-10-22 09:38:42 +02:00
thread-pool.c Include qemu-common.h exactly where needed 2019-06-12 13:20:20 +02:00
throttle.c throttle: Assert that bkt->max is valid in throttle_compute_wait() 2017-09-26 14:46:23 +02:00
timed-average.c Fix some typos found by codespell 2016-05-18 15:04:27 +03:00
trace-events socket: Add backlog parameter to socket_listen 2019-09-03 23:24:42 +02:00
unicode.c json: Reject invalid UTF-8 sequences 2018-08-24 20:26:37 +02:00
uri.c cutils: Provide strchrnul 2018-06-29 12:32:10 +02:00
uuid.c Include qemu-common.h exactly where needed 2019-06-12 13:20:20 +02:00
vfio-helpers.c Report stringified errno in VFIO related errors 2020-02-18 20:20:49 +01:00