From: Christian Borntraeger <borntraeger@de.ibm.com>
To: Paolo Bonzini <pbonzini@redhat.com>,
qemu-devel@nongnu.org, qemu-block@nongnu.org
Cc: mlin@kernel.org, famz@redhat.com, ming.lei@canonical.com,
stefanha@redhat.com, mst@redhat.com
Subject: Re: [Qemu-devel] [RFC PATCH 00/40] Sneak peek of virtio and dataplane changes for 2.6
Date: Wed, 16 Dec 2015 13:54:06 +0100 [thread overview]
Message-ID: <56715EEE.6020208@de.ibm.com> (raw)
In-Reply-To: <5668907A.80604@redhat.com>
On 12/09/2015 09:35 PM, Paolo Bonzini wrote:
>
>
> On 26/11/2015 11:39, Paolo Bonzini wrote:
>> I would really prefer to get rid of vring.c as soon as the infrastructure
>> makes it possible---even if it's faster. We know what makes virtio.c
>> slower, and it's simpler to fix virtio.c than to convert all the other
>> models to vring.c _plus_ make vring.c safe for migration.
>
> I've now pushed some optimizations of exec.c to the same place (branch
> dataplane, git://github.com/bonzini/qemu.git). Basically if the length
> of an address_space_read is constant, and the target ends up being RAM,
> the compiler can inline address_space_read in the caller and in
> particular eliminate the memcpy.
Just some quick remarks before I leave into vacation:
Performance seems to be better than the initial version. I have some
hangs from time to time when shutting down (also with your previous
version)
(gdb) thread apply all bt
Thread 10 (Thread 0x3ff95b7f910 (LWP 9700)):
#0 0x000003ff9707cf56 in syscall () from /lib64/libc.so.6
#1 0x0000000010201586 in futex_wait (val=<optimized out>, f=<optimized out>) at /home/cborntra/REPOS/qemu/include/qemu/futex.h:26
#2 qemu_event_wait (ev=ev@entry=0x107f2cb4 <rcu_call_ready_event>) at /home/cborntra/REPOS/qemu/util/qemu-thread-posix.c:398
#3 0x0000000010214fe2 in call_rcu_thread (opaque=<optimized out>) at /home/cborntra/REPOS/qemu/util/rcu.c:254
#4 0x000003ff971884c6 in start_thread () from /lib64/libpthread.so.0
#5 0x000003ff97082ec2 in thread_start () from /lib64/libc.so.6
Thread 9 (Thread 0x3ff9537f910 (LWP 9701)):
#0 0x000003ff9718f5fa in __lll_lock_wait () from /lib64/libpthread.so.0
#1 0x000003ff9718a582 in pthread_mutex_lock () from /lib64/libpthread.so.0
#2 0x0000000010201062 in qemu_mutex_lock (mutex=<optimized out>) at /home/cborntra/REPOS/qemu/util/qemu-thread-posix.c:69
#3 0x0000000010184ffa in aio_context_acquire (ctx=<optimized out>) at /home/cborntra/REPOS/qemu/async.c:361
#4 0x0000000010185322 in thread_pool_completion_bh (opaque=0x3ff90000ca0) at /home/cborntra/REPOS/qemu/thread-pool.c:168
#5 0x0000000010184b0c in aio_bh_call (bh=<optimized out>) at /home/cborntra/REPOS/qemu/async.c:64
#6 aio_bh_poll (ctx=ctx@entry=0x480e00d0) at /home/cborntra/REPOS/qemu/async.c:96
#7 0x0000000010191ec2 in aio_poll (ctx=0x480e00d0, blocking=blocking@entry=true) at /home/cborntra/REPOS/qemu/aio-posix.c:464
#8 0x00000000100c4bfe in iothread_run (opaque=0x480dfc00) at /home/cborntra/REPOS/qemu/iothread.c:42
#9 0x000003ff971884c6 in start_thread () from /lib64/libpthread.so.0
#10 0x000003ff97082ec2 in thread_start () from /lib64/libc.so.6
Thread 8 (Thread 0x3ff94b7f910 (LWP 9702)):
#0 0x000003ff970766e6 in ppoll () from /lib64/libc.so.6
#1 0x00000000101908c0 in ppoll (__ss=0x0, __timeout=0x0, __nfds=<optimized out>, __fds=<optimized out>) at /usr/include/bits/poll2.h:77
#2 qemu_poll_ns (fds=<optimized out>, nfds=<optimized out>, timeout=timeout@entry=-1) at /home/cborntra/REPOS/qemu/qemu-timer.c:312
#3 0x0000000010191f44 in aio_poll (ctx=0x480e0890, blocking=blocking@entry=true) at /home/cborntra/REPOS/qemu/aio-posix.c:447
#4 0x00000000100c4bfe in iothread_run (opaque=0x480e05c0) at /home/cborntra/REPOS/qemu/iothread.c:42
#5 0x000003ff971884c6 in start_thread () from /lib64/libpthread.so.0
#6 0x000003ff97082ec2 in thread_start () from /lib64/libc.so.6
Thread 7 (Thread 0x3ff8ffff910 (LWP 9703)):
#0 0x000003ff970766e6 in ppoll () from /lib64/libc.so.6
#1 0x00000000101908c0 in ppoll (__ss=0x0, __timeout=0x0, __nfds=<optimized out>, __fds=<optimized out>) at /usr/include/bits/poll2.h:77
#2 qemu_poll_ns (fds=<optimized out>, nfds=<optimized out>, timeout=timeout@entry=-1) at /home/cborntra/REPOS/qemu/qemu-timer.c:312
#3 0x0000000010191f44 in aio_poll (ctx=0x480e1800, blocking=blocking@entry=true) at /home/cborntra/REPOS/qemu/aio-posix.c:447
#4 0x00000000100c4bfe in iothread_run (opaque=0x480e0d60) at /home/cborntra/REPOS/qemu/iothread.c:42
#5 0x000003ff971884c6 in start_thread () from /lib64/libpthread.so.0
#6 0x000003ff97082ec2 in thread_start () from /lib64/libc.so.6
Thread 6 (Thread 0x3ff8f7ff910 (LWP 9704)):
#0 0x000003ff970766e6 in ppoll () from /lib64/libc.so.6
#1 0x00000000101908c0 in ppoll (__ss=0x0, __timeout=0x0, __nfds=<optimized out>, __fds=<optimized out>) at /usr/include/bits/poll2.h:77
#2 qemu_poll_ns (fds=<optimized out>, nfds=<optimized out>, timeout=timeout@entry=-1) at /home/cborntra/REPOS/qemu/qemu-timer.c:312
#3 0x0000000010191f44 in aio_poll (ctx=0x480e1f60, blocking=blocking@entry=true) at /home/cborntra/REPOS/qemu/aio-posix.c:447
#4 0x00000000100c4bfe in iothread_run (opaque=0x480e1cb0) at /home/cborntra/REPOS/qemu/iothread.c:42
#5 0x000003ff971884c6 in start_thread () from /lib64/libpthread.so.0
#6 0x000003ff97082ec2 in thread_start () from /lib64/libc.so.6
Thread 5 (Thread 0x3ff8e2f9910 (LWP 9707)):
#0 0x000003ff9718f61e in __lll_lock_wait () from /lib64/libpthread.so.0
#1 0x000003ff9719262e in __pthread_mutex_cond_lock () from /lib64/libpthread.so.0
#2 0x000003ff9718c5be in pthread_cond_wait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0
#3 0x00000000102011da in qemu_cond_wait (cond=<optimized out>, mutex=mutex@entry=0x103c7780 <qemu_global_mutex>) at /home/cborntra/REPOS/qemu/util/qemu-thread-posix.c:141
#4 0x0000000010044604 in qemu_kvm_wait_io_event (cpu=<optimized out>) at /home/cborntra/REPOS/qemu/cpus.c:1016
#5 qemu_kvm_cpu_thread_fn (arg=0x484ae660) at /home/cborntra/REPOS/qemu/cpus.c:1055
#6 0x000003ff971884c6 in start_thread () from /lib64/libpthread.so.0
---Type <return> to continue, or q <return> to quit---
#7 0x000003ff97082ec2 in thread_start () from /lib64/libc.so.6
Thread 4 (Thread 0x3ff8daf9910 (LWP 9708)):
#0 0x000003ff9718f61e in __lll_lock_wait () from /lib64/libpthread.so.0
#1 0x000003ff9719262e in __pthread_mutex_cond_lock () from /lib64/libpthread.so.0
#2 0x000003ff9718c5be in pthread_cond_wait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0
#3 0x00000000102011da in qemu_cond_wait (cond=<optimized out>, mutex=mutex@entry=0x103c7780 <qemu_global_mutex>) at /home/cborntra/REPOS/qemu/util/qemu-thread-posix.c:141
#4 0x0000000010044604 in qemu_kvm_wait_io_event (cpu=<optimized out>) at /home/cborntra/REPOS/qemu/cpus.c:1016
#5 qemu_kvm_cpu_thread_fn (arg=0x484c0900) at /home/cborntra/REPOS/qemu/cpus.c:1055
#6 0x000003ff971884c6 in start_thread () from /lib64/libpthread.so.0
#7 0x000003ff97082ec2 in thread_start () from /lib64/libc.so.6
Thread 3 (Thread 0x3ff8d2f9910 (LWP 9709)):
#0 0x000003ff9718f61e in __lll_lock_wait () from /lib64/libpthread.so.0
#1 0x000003ff9719262e in __pthread_mutex_cond_lock () from /lib64/libpthread.so.0
#2 0x000003ff9718c5be in pthread_cond_wait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0
#3 0x00000000102011da in qemu_cond_wait (cond=<optimized out>, mutex=mutex@entry=0x103c7780 <qemu_global_mutex>) at /home/cborntra/REPOS/qemu/util/qemu-thread-posix.c:141
#4 0x0000000010044604 in qemu_kvm_wait_io_event (cpu=<optimized out>) at /home/cborntra/REPOS/qemu/cpus.c:1016
#5 qemu_kvm_cpu_thread_fn (arg=0x484d2ba0) at /home/cborntra/REPOS/qemu/cpus.c:1055
#6 0x000003ff971884c6 in start_thread () from /lib64/libpthread.so.0
#7 0x000003ff97082ec2 in thread_start () from /lib64/libc.so.6
Thread 2 (Thread 0x3ff8ca7f910 (LWP 9710)):
#0 0x000003ff9718f61e in __lll_lock_wait () from /lib64/libpthread.so.0
#1 0x000003ff9719262e in __pthread_mutex_cond_lock () from /lib64/libpthread.so.0
#2 0x000003ff9718c5be in pthread_cond_wait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0
#3 0x00000000102011da in qemu_cond_wait (cond=<optimized out>, mutex=mutex@entry=0x103c7780 <qemu_global_mutex>) at /home/cborntra/REPOS/qemu/util/qemu-thread-posix.c:141
#4 0x0000000010044604 in qemu_kvm_wait_io_event (cpu=<optimized out>) at /home/cborntra/REPOS/qemu/cpus.c:1016
#5 qemu_kvm_cpu_thread_fn (arg=0x484e4e40) at /home/cborntra/REPOS/qemu/cpus.c:1055
#6 0x000003ff971884c6 in start_thread () from /lib64/libpthread.so.0
#7 0x000003ff97082ec2 in thread_start () from /lib64/libc.so.6
Thread 1 (Thread 0x3ff98bdcbb0 (LWP 9690)):
#0 0x000003ff970766e6 in ppoll () from /lib64/libc.so.6
#1 0x00000000101908c0 in ppoll (__ss=0x0, __timeout=0x0, __nfds=<optimized out>, __fds=<optimized out>) at /usr/include/bits/poll2.h:77
#2 qemu_poll_ns (fds=<optimized out>, nfds=<optimized out>, timeout=timeout@entry=-1) at /home/cborntra/REPOS/qemu/qemu-timer.c:312
#3 0x0000000010191f44 in aio_poll (ctx=ctx@entry=0x480e00d0, blocking=blocking@entry=true) at /home/cborntra/REPOS/qemu/aio-posix.c:447
#4 0x00000000101c8ff4 in bdrv_flush (bs=bs@entry=0x480fa160) at /home/cborntra/REPOS/qemu/block/io.c:2426
#5 0x000000001018bba6 in bdrv_close (bs=bs@entry=0x480fa160) at /home/cborntra/REPOS/qemu/block.c:1914
#6 0x000000001018c0f6 in bdrv_close_all () at /home/cborntra/REPOS/qemu/block.c:1974
#7 0x0000000010014102 in main (argc=<optimized out>, argv=<optimized out>, envp=<optimized out>) at /home/cborntra/REPOS/qemu/vl.c:4687
(gdb)
next prev parent reply other threads:[~2015-12-16 12:54 UTC|newest]
Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-11-24 18:00 [Qemu-devel] [RFC PATCH 00/40] Sneak peek of virtio and dataplane changes for 2.6 Paolo Bonzini
2015-11-24 18:00 ` [Qemu-devel] [PATCH 01/40] 9pfs: allocate pdus with g_malloc/g_free Paolo Bonzini
2015-11-30 2:27 ` Fam Zheng
2015-11-30 2:33 ` Fam Zheng
2015-11-30 16:35 ` Greg Kurz
2015-11-24 18:00 ` [Qemu-devel] [PATCH 02/40] virtio: move VirtQueueElement at the beginning of the structs Paolo Bonzini
2015-11-24 18:00 ` [Qemu-devel] [PATCH 03/40] virtio: move allocation to virtqueue_pop/vring_pop Paolo Bonzini
2015-11-30 3:00 ` Fam Zheng
2015-11-24 18:00 ` [Qemu-devel] [PATCH 04/40] virtio: introduce qemu_get/put_virtqueue_element Paolo Bonzini
2015-11-24 18:00 ` [Qemu-devel] [PATCH 05/40] virtio: read/write the VirtQueueElement a field at a time Paolo Bonzini
2015-11-30 9:47 ` Fam Zheng
2015-11-30 10:37 ` Paolo Bonzini
2015-11-24 18:00 ` [Qemu-devel] [PATCH 06/40] virtio: introduce virtqueue_alloc_element Paolo Bonzini
2015-11-24 18:00 ` [Qemu-devel] [PATCH 07/40] virtio: slim down allocation of VirtQueueElements Paolo Bonzini
2015-11-30 3:24 ` Fam Zheng
2015-11-30 8:36 ` Paolo Bonzini
2015-11-24 18:00 ` [Qemu-devel] [PATCH 08/40] vring: " Paolo Bonzini
2015-11-24 18:01 ` [Qemu-devel] [PATCH 09/40] vring: make vring_enable_notification return void Paolo Bonzini
2015-11-24 18:01 ` [Qemu-devel] [PATCH 10/40] virtio: combine the read of a descriptor Paolo Bonzini
2015-11-24 18:01 ` [Qemu-devel] [PATCH 11/40] virtio: add AioContext-specific function for host notifiers Paolo Bonzini
2015-11-24 18:01 ` [Qemu-devel] [PATCH 12/40] virtio: export vring_notify as virtio_should_notify Paolo Bonzini
2015-11-24 18:01 ` [Qemu-devel] [PATCH 13/40] virtio-blk: fix "disabled data plane" mode Paolo Bonzini
2015-11-24 18:01 ` [Qemu-devel] [PATCH 14/40] virtio-blk: do not use vring in dataplane Paolo Bonzini
2015-11-24 18:01 ` [Qemu-devel] [PATCH 15/40] virtio-scsi: " Paolo Bonzini
2015-11-24 18:01 ` [Qemu-devel] [PATCH 16/40] vring: remove Paolo Bonzini
2015-11-24 18:01 ` [Qemu-devel] [PATCH 17/40] iothread: release AioContext around aio_poll Paolo Bonzini
2015-11-24 18:01 ` [Qemu-devel] [PATCH 18/40] qemu-thread: introduce QemuRecMutex Paolo Bonzini
2015-11-24 18:01 ` [Qemu-devel] [PATCH 19/40] aio: convert from RFifoLock to QemuRecMutex Paolo Bonzini
2015-11-24 18:01 ` [Qemu-devel] [PATCH 20/40] aio: rename bh_lock to list_lock Paolo Bonzini
2015-11-24 18:01 ` [Qemu-devel] [PATCH 21/40] qemu-thread: introduce QemuLockCnt Paolo Bonzini
2015-11-24 18:01 ` [Qemu-devel] [PATCH 22/40] aio: make ctx->list_lock a QemuLockCnt, subsuming ctx->walking_bh Paolo Bonzini
2015-11-24 18:01 ` [Qemu-devel] [PATCH 23/40] qemu-thread: optimize QemuLockCnt with futexes on Linux Paolo Bonzini
2015-11-24 18:01 ` [Qemu-devel] [PATCH 24/40] aio: tweak walking in dispatch phase Paolo Bonzini
2015-11-24 18:01 ` [Qemu-devel] [PATCH 25/40] aio-posix: remove walking_handlers, protecting AioHandler list with list_lock Paolo Bonzini
2015-11-24 18:01 ` [Qemu-devel] [PATCH 26/40] aio-win32: " Paolo Bonzini
2015-11-24 18:01 ` [Qemu-devel] [PATCH 27/40] aio: document locking Paolo Bonzini
2015-11-24 18:01 ` [Qemu-devel] [PATCH 28/40] aio: push aio_context_acquire/release down to dispatching Paolo Bonzini
2015-11-24 18:01 ` [Qemu-devel] [PATCH 29/40] quorum: use atomics for rewrite_count Paolo Bonzini
2015-11-24 18:01 ` [Qemu-devel] [PATCH 30/40] quorum: split quorum_fifo_aio_cb from quorum_aio_cb Paolo Bonzini
2015-11-24 18:01 ` [Qemu-devel] [PATCH 31/40] qed: introduce qed_aio_start_io and qed_aio_next_io_cb Paolo Bonzini
2015-11-24 18:01 ` [Qemu-devel] [PATCH 32/40] block: explicitly acquire aiocontext in callbacks that need it Paolo Bonzini
2015-11-24 18:01 ` [Qemu-devel] [PATCH 33/40] block: explicitly acquire aiocontext in bottom halves " Paolo Bonzini
2015-11-24 18:01 ` [Qemu-devel] [PATCH 34/40] block: explicitly acquire aiocontext in timers " Paolo Bonzini
2015-11-24 18:01 ` [Qemu-devel] [PATCH 35/40] block: explicitly acquire aiocontext in aio callbacks " Paolo Bonzini
2015-11-24 18:01 ` [Qemu-devel] [PATCH 36/40] aio: update locking documentation Paolo Bonzini
2015-11-24 18:01 ` [Qemu-devel] [PATCH 37/40] async: optimize aio_bh_poll Paolo Bonzini
2015-11-24 18:01 ` [Qemu-devel] [PATCH 38/40] aio-posix: partially inline aio_dispatch into aio_poll Paolo Bonzini
2015-11-24 18:01 ` [Qemu-devel] [PATCH 39/40] async: remove unnecessary inc/dec pairs Paolo Bonzini
2015-11-24 18:01 ` [Qemu-devel] [PATCH 40/40] dma-helpers: avoid lock inversion with AioContext Paolo Bonzini
2015-11-26 9:36 ` [Qemu-devel] [RFC PATCH 00/40] Sneak peek of virtio and dataplane changes for 2.6 Christian Borntraeger
2015-11-26 9:41 ` Christian Borntraeger
2015-11-26 10:39 ` Paolo Bonzini
2015-12-09 20:35 ` Paolo Bonzini
2015-12-16 12:54 ` Christian Borntraeger [this message]
2015-12-16 14:40 ` Christian Borntraeger
2015-12-16 17:42 ` Paolo Bonzini
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