Re: [libvirt] increase number of libvirt threads by starting tansient guest doamin - is it a bug?

web2 wrote: > Hi > > ----------------ursprüngliche Nachricht----------------- > Von: "Michal Privoznik" mprivozn(a)redhat.com > An: "web2" ustermann78(a)web.de , "libvirt-users redhat.com" > , "libvirt-list redhat.com" > Datum: Wed, 01 Oct 2014 18:12:45 +0200 > ------------------------------------------------- > > > >> On 01.10.2014 10:31, web2 wrote: >> >>> Hello, >>> >>> sorry for my later answer. >>> >>> so, after i started libvirtd (no vm´s running) and attach gdb i get the >>> following threads >>> >>> (gdb) info thread >>> Id Target Id Frame >>> 11 Thread 0x7f18fef4e700 (LWP 20695) "libvirtd" >>> pthread_cond_wait@(a)GLIBC_2.3.2 () at >>> >>> ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 >>> >>> 10 Thread 0x7f18fe74d700 (LWP 20696) "libvirtd" >>> pthread_cond_wait@(a)GLIBC_2.3.2 () at >>> >>> ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 >>> >>> 9 Thread 0x7f18fdf4c700 (LWP 20697) "libvirtd" >>> pthread_cond_wait@(a)GLIBC_2.3.2 () at >>> >>> ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 >>> >>> 8 Thread 0x7f18fd74b700 (LWP 20698) "libvirtd" >>> pthread_cond_wait@(a)GLIBC_2.3.2 () at >>> >>> ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 >>> >>> 7 Thread 0x7f18fcf4a700 (LWP 20699) "libvirtd" >>> pthread_cond_wait@(a)GLIBC_2.3.2 () at >>> >>> ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 >>> >>> 6 Thread 0x7f18fc749700 (LWP 20700) "libvirtd" >>> pthread_cond_wait@(a)GLIBC_2.3.2 () at >>> >>> ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 >>> >>> 5 Thread 0x7f18fbf48700 (LWP 20701) "libvirtd" >>> pthread_cond_wait@(a)GLIBC_2.3.2 () at >>> >>> ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 >>> >>> 4 Thread 0x7f18fb747700 (LWP 20702) "libvirtd" >>> pthread_cond_wait@(a)GLIBC_2.3.2 () at >>> >>> ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 >>> >>> 3 Thread 0x7f18faf46700 (LWP 20703) "libvirtd" >>> pthread_cond_wait@(a)GLIBC_2.3.2 () at >>> >>> ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 >>> >>> 2 Thread 0x7f18fa745700 (LWP 20704) "libvirtd" >>> pthread_cond_wait@(a)GLIBC_2.3.2 () at >>> >>> ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 >>> >>> * 1 Thread 0x7f190892f840 (LWP 20694) "libvirtd" >>> 0x00007f190677d7cd in >>> poll () at ../sysdeps/unix/syscall-template.S:81 >>> >>> if i restore an persistent domain, i see the following in gdb: >>> >>> Detaching after fork from child process 20880. >>> Detaching after fork from child process 20882. >>> [New Thread 0x7f190893d700 (LWP 20883)] >>> Detaching after fork from child process 20890. >>> Detaching after fork from child process 20906. >>> >>> (gdb) info thread >>> Id Target Id Frame >>> 12 Thread 0x7f190893d700 (LWP 20883) "libvirtd" >>> 0x00007f1906e6684d in >>> read () at ../sysdeps/unix/syscall-template.S:81 >>> 11 Thread 0x7f18fef4e700 (LWP 20695) "libvirtd" >>> pthread_cond_wait@(a)GLIBC_2.3.2 () at >>> >>> ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 >>> >>> 10 Thread 0x7f18fe74d700 (LWP 20696) "libvirtd" >>> pthread_cond_wait@(a)GLIBC_2.3.2 () at >>> >>> ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 >>> >>> 9 Thread 0x7f18fdf4c700 (LWP 20697) "libvirtd" >>> pthread_cond_wait@(a)GLIBC_2.3.2 () at >>> >>> ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 >>> >>> 8 Thread 0x7f18fd74b700 (LWP 20698) "libvirtd" >>> pthread_cond_wait@(a)GLIBC_2.3.2 () at >>> >>> ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 >>> >>> 7 Thread 0x7f18fcf4a700 (LWP 20699) "libvirtd" >>> pthread_cond_wait@(a)GLIBC_2.3.2 () at >>> >>> ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 >>> >>> 6 Thread 0x7f18fc749700 (LWP 20700) "libvirtd" >>> pthread_cond_wait@(a)GLIBC_2.3.2 () at >>> >>> ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 >>> >>> 5 Thread 0x7f18fbf48700 (LWP 20701) "libvirtd" >>> pthread_cond_wait@(a)GLIBC_2.3.2 () at >>> >>> ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 >>> >>> 4 Thread 0x7f18fb747700 (LWP 20702) "libvirtd" >>> pthread_cond_wait@(a)GLIBC_2.3.2 () at >>> >>> ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 >>> >>> 3 Thread 0x7f18faf46700 (LWP 20703) "libvirtd" >>> pthread_cond_wait@(a)GLIBC_2.3.2 () at >>> >>> ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 >>> >>> 2 Thread 0x7f18fa745700 (LWP 20704) "libvirtd" >>> pthread_cond_wait@(a)GLIBC_2.3.2 () at >>> >>> ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 >>> >>> * 1 Thread 0x7f190892f840 (LWP 20694) "libvirtd" >>> 0x00007f190677d7cd in >>> poll () at ../sysdeps/unix/syscall-template.S:81 >>> >>> if i now destroy this vm i get the following: >>> >>> >>> (gdb) info thread >>> Id Target Id Frame >>> 12 Thread 0x7f190893d700 (LWP 20883) "libvirtd" >>> 0x00007f1906e6684d in >>> read () at ../sysdeps/unix/syscall-template.S:81 >>> 11 Thread 0x7f18fef4e700 (LWP 20695) "libvirtd" >>> pthread_cond_wait@(a)GLIBC_2.3.2 () at >>> >>> ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 >>> >>> 10 Thread 0x7f18fe74d700 (LWP 20696) "libvirtd" >>> pthread_cond_wait@(a)GLIBC_2.3.2 () at >>> >>> ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 >>> >>> 9 Thread 0x7f18fdf4c700 (LWP 20697) "libvirtd" >>> pthread_cond_wait@(a)GLIBC_2.3.2 () at >>> >>> ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 >>> >>> 8 Thread 0x7f18fd74b700 (LWP 20698) "libvirtd" >>> pthread_cond_wait@(a)GLIBC_2.3.2 () at >>> >>> ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 >>> >>> 7 Thread 0x7f18fcf4a700 (LWP 20699) "libvirtd" >>> pthread_cond_wait@(a)GLIBC_2.3.2 () at >>> >>> ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 >>> >>> 6 Thread 0x7f18fc749700 (LWP 20700) "libvirtd" >>> pthread_cond_wait@(a)GLIBC_2.3.2 () at >>> >>> ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 >>> >>> 5 Thread 0x7f18fbf48700 (LWP 20701) "libvirtd" >>> pthread_cond_wait@(a)GLIBC_2.3.2 () at >>> >>> ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 >>> >>> 4 Thread 0x7f18fb747700 (LWP 20702) "libvirtd" >>> pthread_cond_wait@(a)GLIBC_2.3.2 () at >>> >>> ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 >>> >>> 3 Thread 0x7f18faf46700 (LWP 20703) "libvirtd" >>> pthread_cond_wait@(a)GLIBC_2.3.2 () at >>> >>> ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 >>> >>> 2 Thread 0x7f18fa745700 (LWP 20704) "libvirtd" >>> pthread_cond_wait@(a)GLIBC_2.3.2 () at >>> >>> ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185 >>> >>> * 1 Thread 0x7f190892f840 (LWP 20694) "libvirtd" >>> 0x00007f190677d7cd in >>> poll () at ../sysdeps/unix/syscall-template.S:81 >>> >>> attaching thread Id 12 and bt: >>> (gdb) thread 12 >>> [Switching to thread 12 (Thread 0x7f190893d700 (LWP 20883))] >>> #0 0x00007f1906e6684d in read () at >>> ../sysdeps/unix/syscall-template.S:81 >>> 81 T_PSEUDO (SYSCALL_SYMBOL, SYSCALL_NAME, SYSCALL_NARGS) >>> (gdb) bt >>> #0 0x00007f1906e6684d in read () at >>> ../sysdeps/unix/syscall-template.S:81 >>> #1 0x00007f18f8c415be in read (__nbytes=16, >>> __buf=0x7f18d4000c50, >>> __fd=26) at /usr/include/bits/unistd.h:44 >>> #2 read_all (fd=26, data=data@entry =0x7f18d4000c50, >>> len=len@entry =16, >>> nonblocking=nonblocking@entry =0) at xs.c:374 >>> #3 0x00007f18f8c41675 in read_message (h=h@entry >>> =0x7f18e8001070, >>> nonblocking=nonblocking@entry =0) at xs.c:1139 >>> #4 0x00007f18f8c41e90 in read_thread (arg=0x7f18e8001070) at >>> xs.c:1211 >>> #5 0x00007f1906e5ff35 in start_thread (arg=0x7f190893d700) at >>> pthread_create.c:309 >>> #6 0x00007f1906787c3d in clone () at >>> ../sysdeps/unix/sysv/linux/x86_64/clone.S:111 >>> >>> and then bt full: >>> >>> (gdb) bt full >>> #0 0x00007f1906e6684d in read () at >>> ../sysdeps/unix/syscall-template.S:81 >>> No locals. >>> #1 0x00007f18f8c415be in read (__nbytes=16, >>> __buf=0x7f18d4000c50, >>> __fd=26) at /usr/include/bits/unistd.h:44 >>> No locals. >>> #2 read_all (fd=26, data=data@entry =0x7f18d4000c50, >>> len=len@entry =16, >>> nonblocking=nonblocking@entry =0) at xs.c:374 >>> done = <optimized out> >>> #3 0x00007f18f8c41675 in read_message (h=h@entry >>> =0x7f18e8001070, >>> nonblocking=nonblocking@entry =0) at xs.c:1139 >>> __clframe = {__cancel_routine = <optimized out>, __cancel_arg = >>> 0x7f18d4000c40, __do_it = 1, __cancel_type = <optimized out>} >>> msg = 0x7f18d4000c40 >>> body = 0x0 >>> saved_errno = 0 >>> ret = -1 >>> #4 0x00007f18f8c41e90 in read_thread (arg=0x7f18e8001070) at >>> xs.c:1211 >>> h = 0x7f18e8001070 >>> fd = <optimized out> >>> >> This stack doesn't come from libvirt. I suspect it comes from a library >> that libvirtd is linked with. Yep, a thread created by libxl. >> Maybe libxl? What's the connection uri >> you're using? >> > > i use xen:///. as i said early, i do tests with xen xm´s. xend is disabled, so i > use the libxl. > Earlier you mentioned using libvirt 1.1.3 for your Xen hosts. Have you tried the freshly released 1.2.9? I didn't see the problem with libvirt git master and Xen 4.4.1.

Regards, Jim