From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:56140) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1d5wFd-0004CD-Ag for qemu-devel@nongnu.org; Wed, 03 May 2017 11:31:38 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1d5wFY-0008UQ-Ng for qemu-devel@nongnu.org; Wed, 03 May 2017 11:31:37 -0400 Received: from mx1.redhat.com ([209.132.183.28]:34772) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1d5wFY-0008TH-E6 for qemu-devel@nongnu.org; Wed, 03 May 2017 11:31:32 -0400 Date: Wed, 3 May 2017 16:31:22 +0100 From: "Richard W.M. Jones" Message-ID: <20170503153122.GC27432@redhat.com> References: <20170227163447.20428-1-stefanha@redhat.com> <20170227163447.20428-2-stefanha@redhat.com> <20170503145418.GB27432@redhat.com> <182d640c-c892-993e-06d4-a9cdd9f363d6@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <182d640c-c892-993e-06d4-a9cdd9f363d6@redhat.com> Subject: Re: [Qemu-devel] [PULL 1/4] curl: do not use aio_context_acquire/release List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paolo Bonzini Cc: Stefan Hajnoczi , Peter Maydell , qemu-devel@nongnu.org On Wed, May 03, 2017 at 04:59:22PM +0200, Paolo Bonzini wrote: > Maybe there is, can you grab an all-threads backtrace via gdb? Program received signal SIGINT, Interrupt. 0x00007f1d57f861bd in __lll_lock_wait () from /lib64/libpthread.so.0 (gdb) t a a bt Thread 9 (Thread 0x7f1d49967700 (LWP 29949)): #0 0x00007f1d53a39bf9 in syscall () at /lib64/libc.so.6 #1 0x000055ea5c358856 in qemu_event_wait (val=, f=) at /home/rjones/d/qemu/include/qemu/futex.h:26 #2 0x000055ea5c358856 in qemu_event_wait (ev=ev@entry=0x55ea5cde4ac4 ) at util/qemu-thread-posix.c:399 #3 0x000055ea5c3680fe in call_rcu_thread (opaque=) at util/rcu.c:249 #4 0x00007f1d57f7fdc5 in start_thread () at /lib64/libpthread.so.0 #5 0x00007f1d53a3f73d in clone () at /lib64/libc.so.6 Thread 7 (Thread 0x7f1d46987700 (LWP 29955)): #0 0x00007f1d57f861bd in __lll_lock_wait () at /lib64/libpthread.so.0 #1 0x00007f1d57f81d02 in _L_lock_791 () at /lib64/libpthread.so.0 #2 0x00007f1d57f81c08 in pthread_mutex_lock () at /lib64/libpthread.so.0 #3 0x000055ea5c3583e9 in qemu_mutex_lock (mutex=mutex@entry=0x55ea5c9a2400 ) at util/qemu-thread-posix.c:60 #4 0x000055ea5bff512c in qemu_mutex_lock_iothread () at /home/rjones/d/qemu/cpus.c:1565 #5 0x000055ea5c0081c7 in kvm_cpu_exec (cpu=cpu@entry=0x55ea5e7df020) at /home/rjones/d/qemu/kvm-all.c:2096 #6 0x000055ea5bff5332 in qemu_kvm_cpu_thread_fn (arg=0x55ea5e7df020) at /home/rjones/d/qemu/cpus.c:1118 #7 0x00007f1d57f7fdc5 in start_thread () at /lib64/libpthread.so.0 #8 0x00007f1d53a3f73d in clone () at /lib64/libc.so.6 Thread 1 (Thread 0x7f1d5a4e2c00 (LWP 29947)): #0 0x00007f1d57f861bd in __lll_lock_wait () at /lib64/libpthread.so.0 #1 0x00007f1d57f81d02 in _L_lock_791 () at /lib64/libpthread.so.0 #2 0x00007f1d57f81c08 in pthread_mutex_lock () at /lib64/libpthread.so.0 #3 0x000055ea5c3583e9 in qemu_mutex_lock (mutex=mutex@entry=0x55ea5e5ac178) at util/qemu-thread-posix.c:60 #4 0x000055ea5c2fb2d1 in curl_readv_bh_cb (p=0x55ea6013c620) at block/curl.c:824 #5 0x000055ea5c352fe1 in aio_bh_poll (bh=0x55ea60eb99d0) at util/async.c:90 #6 0x000055ea5c352fe1 in aio_bh_poll (ctx=ctx@entry=0x55ea5e555970) at util/async.c:118 #7 0x000055ea5c3563c4 in aio_poll (ctx=0x55ea5e555970, blocking=blocking@entry=true) at util/aio-posix.c:682 #8 0x000055ea5c2fb09e in curl_init_state (bs=0x55ea5e5a56b0, s=s@entry=0x55ea5e5ab100) at block/curl.c:470 #9 0x000055ea5c2fb39b in curl_readv_bh_cb (p=0x55ea5f650c30) at block/curl.c:839 #10 0x000055ea5c352fe1 in aio_bh_poll (bh=0x55ea60eb1910) at util/async.c:90 #11 0x000055ea5c352fe1 in aio_bh_poll (ctx=ctx@entry=0x55ea5e555970) at util/async.c:118 #12 0x000055ea5c355f80 in aio_dispatch (ctx=0x55ea5e555970) at util/aio-posix.c:429 #13 0x000055ea5c352ebe in aio_ctx_dispatch (source=, callback=, user_data=) at util/async.c:261 #14 0x00007f1d55489d7a in g_main_context_dispatch () at /lib64/libglib-2.0.so.0 #15 0x000055ea5c35523c in main_loop_wait () at util/main-loop.c:213 #16 0x000055ea5c35523c in main_loop_wait (timeout=) at util/main-loop.c:261 ---Type to continue, or q to quit--- #17 0x000055ea5c35523c in main_loop_wait (nonblocking=nonblocking@entry=0) at util/main-loop.c:517 #18 0x000055ea5bfb44a7 in main () at vl.c:1899 #19 0x000055ea5bfb44a7 in main (argc=, argv=, envp=) at vl.c:4717 I'll get you one with more symbols in a minute, just installing debuginfo ... BTW this bug is reproducible on both Fedora 26 and RHEL 7.4 (in both cases with either qemu 2.9 or qemu from git). Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com Fedora Windows cross-compiler. Compile Windows programs, test, and build Windows installers. Over 100 libraries supported. http://fedoraproject.org/wiki/MinGW