Temp pages will need to grow if we want to have multiple channels for postcopy,
because each channel will need its own temp page to cache huge page data.
Before doing that, cleanup the related code. No functional change intended.
Since at it, touch up the errno handling a little bit on the setup side.
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
This patch simplifies unqueue_page() on both sides of it (itself, and caller).
Firstly, due to the fact that right after unqueue_page() returned true, we'll
definitely send a huge page (see ram_save_huge_page() call - it will _never_
exit before finish sending that huge page), so unqueue_page() does not need to
jump in small page size if huge page is enabled on the ramblock. IOW, it's
destined that only the 1st 4K page will be valid, when unqueue the 2nd+ time
we'll notice the whole huge page has already been sent anyway. Switching to
operating on huge page reduces a lot of the loops of redundant unqueue_page().
Meanwhile, drop the dirty check. It's not helpful to call test_bit() every
time to jump over clean pages, as ram_save_host_page() has already done so,
while in a faster way (see commit ba1b7c812c ("migration/ram: Optimize
ram_save_host_page()", 2021-05-13)). So that's not necessary too.
Drop the two tracepoints along the way - based on above analysis it's very
possible that no one is really using it..
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Add a helper to detect whether postcopy has pending request.
Since at it, cleanup the code a bit, e.g. in unqueue_page() we shouldn't need
to check it again on queue empty because we're the only one (besides cleanup
code, which should never run during this process) that will take a request off
the list, so the request list can only grow but not shrink under the hood.
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
This patch allows us to read the tid even without blocktime feature enabled.
It's useful when tracing postcopy fault thread on faulted pages to show thread
id too with the address.
Remove the comments - they're merely not helpful at all.
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
We used to do off-by-one fixup for pss->page when finished one host huge page
transfer. That seems to be unnecesary at all. Drop it.
Cc: Keqian Zhu <zhukeqian1@huawei.com>
Cc: Kunkun Jiang <jiangkunkun@huawei.com>
Cc: Andrey Gruzdev <andrey.gruzdev@virtuozzo.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Provide information on the number of bytes copied in the pre-copy,
downtime and post-copy phases of migration.
Signed-off-by: David Edmondson <david.edmondson@oracle.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Replace direct manipulation of ram_counters.transferred with a
function.
Signed-off-by: David Edmondson <david.edmondson@oracle.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
postcopy_send_discard_bm_ram() always return zero. Since it can't
fail, simplify and do not return anything.
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: David Edmondson <david.edmondson@oracle.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
It will just never fail. Drop those return values where they're constantly
zeros.
A tiny touch-up on the tracepoint so trace_ram_postcopy_send_discard_bitmap()
is called after the logic itself (which sounds more reasonable).
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Right now we loop ramblocks for twice, the 1st time chunk the dirty bits with
huge page information; the 2nd time we send the discard ranges. That's not
necessary - we can do them in a single loop.
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
This function calls three functions:
- postcopy_discard_send_init(ms, block->idstr);
- postcopy_chunk_hostpages_pass(ms, block);
- postcopy_discard_send_finish(ms);
However only the 2nd function call is meaningful. It's major role is to make
sure dirty bits are applied in host-page-size granule, so there will be no
partial dirty bits set for a whole host page if huge pages are used.
The 1st/3rd call are for latter when we want to send the disgard ranges.
They're mostly no-op here besides some tracepoints (which are misleading!).
Drop them, then we can directly drop postcopy_chunk_hostpages() as a whole
because we can call postcopy_chunk_hostpages_pass() directly.
There're still some nice comments above postcopy_chunk_hostpages() that explain
what it does. Copy it over to the caller's site.
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
It always return zero, because it just can't go wrong so far. Simplify the
code with no functional change.
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
I planned to add "#ifdef DEBUG_POSTCOPY" around the function too because
otherwise it'll be compiled into qemu binary even if it'll never be used. Then
I found that maybe it's easier to just drop it for good..
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Just a removal of an unused comment.
a0a8aa147a did many fixes and removed the parameter named "ms", but forget to remove the corresponding comment in function named "ram_save_host_page".
Signed-off-by: Xu Zheng <xuzheng@cmss.chinamobile.com>
Signed-off-by: Mao Zhongyi <maozhongyi@cmss.chinamobile.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Should qemu_savevm_state_iterate() encounter a failure when calling a
particular save_live_iterate function, report the error code returned
by the function.
Signed-off-by: David Edmondson <david.edmondson@oracle.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
The MIGRATION_STATUS_ACTIVE indicates that migration is running.
Remove it to be handled by the default operation,
It should be part of the unknown ending states.
Signed-off-by: Zhang Chen <chen.zhang@intel.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
COLO dose not support postcopy migration and remove the Fixme.
Signed-off-by: Zhang Chen <chen.zhang@intel.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
In the migration_completion() no other status is expected, for
example MIGRATION_STATUS_CANCELLING, MIGRATION_STATUS_CANCELLED, etc.
Signed-off-by: Zhang Chen <chen.zhang@intel.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
Rename num_normal_pages to total_normal_pages (peter)
We are only sending normal pages through multifd channels.
Later on this series, we are going to also send zero pages.
We are going to detect if a page is zero or non zero in the multifd
channel thread, not on the main thread.
So we receive an array of pages page->offset[N]
And we will end with:
p->normal[N - zero_pages]
p->zero[zero_pages].
In this patch, we just copy all the pages in offset to normal.
for (i = 0; i < pages->num; i++) {
p->narmal[p->normal_num] = pages->offset[i];
p->normal_num++:
}
Later in the series this becomes:
for (i = 0; i < pages->num; i++) {
if (buffer_is_zero(page->offset[i])) {
p->zerol[p->zero_num] = pages->offset[i];
p->zero_num++:
} else {
p->narmal[p->normal_num] = pages->offset[i];
p->normal_num++:
}
}
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
Improving comment (dave)
Renaming num_normal_pages to total_normal_pages (peter)
Until now, we wrote the packet header with write(), and the rest of the
pages with writev(). Just increase the size of the iovec and do a
single writev().
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
It happens that there are functions to calculate the worst possible
compression size for a packet. Use them.
Suggested-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
We always need to call it when we find a zero page, so put it in a
single place.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Remove the mask in the call to ram_release_pages(). Nothing else does
it, and if the offset has that bits set, we have a lot of trouble.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Remove the pages argument. And s/pages/page/
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
---
- Use 1LL instead of casts (philmd)
- Change the whole 1ULL for TARGET_PAGE_SIZE
We only need last_stage in two places and we are passing it all
around. Just add a field to RAMState that passes it.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
---
Repeat subject (philmd suggestion)
So printing it as %d is wrong. Notice that for the channel id, that
is an uint8_t, but I changed it anyways for consistency.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Adaptive polling measures the execution time of the polling check plus
handlers called when a polled event becomes ready. Handlers can take a
significant amount of time, making it look like polling was running for
a long time when in fact the event handler was running for a long time.
For example, on Linux the io_submit(2) syscall invoked when a virtio-blk
device's virtqueue becomes ready can take 10s of microseconds. This
can exceed the default polling interval (32 microseconds) and cause
adaptive polling to stop polling.
By excluding the handler's execution time from the polling check we make
the adaptive polling calculation more accurate. As a result, the event
loop now stays in polling mode where previously it would have fallen
back to file descriptor monitoring.
The following data was collected with virtio-blk num-queues=2
event_idx=off using an IOThread. Before:
168k IOPS, IOThread syscalls:
9837.115 ( 0.020 ms): IO iothread1/620155 io_submit(ctx_id: 140512552468480, nr: 16, iocbpp: 0x7fcb9f937db0) = 16
9837.158 ( 0.002 ms): IO iothread1/620155 write(fd: 103, buf: 0x556a2ef71b88, count: 8) = 8
9837.161 ( 0.001 ms): IO iothread1/620155 write(fd: 104, buf: 0x556a2ef71b88, count: 8) = 8
9837.163 ( 0.001 ms): IO iothread1/620155 ppoll(ufds: 0x7fcb90002800, nfds: 4, tsp: 0x7fcb9f1342d0, sigsetsize: 8) = 3
9837.164 ( 0.001 ms): IO iothread1/620155 read(fd: 107, buf: 0x7fcb9f939cc0, count: 512) = 8
9837.174 ( 0.001 ms): IO iothread1/620155 read(fd: 105, buf: 0x7fcb9f939cc0, count: 512) = 8
9837.176 ( 0.001 ms): IO iothread1/620155 read(fd: 106, buf: 0x7fcb9f939cc0, count: 512) = 8
9837.209 ( 0.035 ms): IO iothread1/620155 io_submit(ctx_id: 140512552468480, nr: 32, iocbpp: 0x7fca7d0cebe0) = 32
174k IOPS (+3.6%), IOThread syscalls:
9809.566 ( 0.036 ms): IO iothread1/623061 io_submit(ctx_id: 140539805028352, nr: 32, iocbpp: 0x7fd0cdd62be0) = 32
9809.625 ( 0.001 ms): IO iothread1/623061 write(fd: 103, buf: 0x5647cfba5f58, count: 8) = 8
9809.627 ( 0.002 ms): IO iothread1/623061 write(fd: 104, buf: 0x5647cfba5f58, count: 8) = 8
9809.663 ( 0.036 ms): IO iothread1/623061 io_submit(ctx_id: 140539805028352, nr: 32, iocbpp: 0x7fd0d0388b50) = 32
Notice that ppoll(2) and eventfd read(2) syscalls are eliminated because
the IOThread stays in polling mode instead of falling back to file
descriptor monitoring.
As usual, polling is not implemented on Windows so this patch ignores
the new io_poll_read() callback in aio-win32.c.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Message-id: 20211207132336.36627-2-stefanha@redhat.com
[Fixed up aio_set_event_notifier() calls in
tests/unit/test-fdmon-epoll.c added after this series was queued.
--Stefan]
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
virtio-net-failover test tries several device combinations that produces
some expected warnings.
These warning can be confusing, so we disable them during the qtest
sequence.
Reported-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Message-Id: <20211220145314.390697-1-lvivier@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
[thuth: Fix memory leak by using error_free()]
Signed-off-by: Thomas Huth <thuth@redhat.com>
There is no need to put some trace code in the critical section.
So, moving it behind qemu_mutex_unlock_iothread() can reduce the
lock time.
Signed-off-by: Lei Rao <lei.rao@intel.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
When doing live migration with multifd channels 8, 16 or larger number,
the guest hangs in the presence of the network errors such as missing TCP ACKs.
At sender's side:
The main thread is blocked on qemu_thread_join, migration_fd_cleanup
is called because one thread fails on qio_channel_write_all when
the network problem happens and other send threads are blocked on sendmsg.
They could not be terminated. So the main thread is blocked on qemu_thread_join
to wait for the threads terminated.
(gdb) bt
0 0x00007f30c8dcffc0 in __pthread_clockjoin_ex () at /lib64/libpthread.so.0
1 0x000055cbb716084b in qemu_thread_join (thread=0x55cbb881f418) at ../util/qemu-thread-posix.c:627
2 0x000055cbb6b54e40 in multifd_save_cleanup () at ../migration/multifd.c:542
3 0x000055cbb6b4de06 in migrate_fd_cleanup (s=0x55cbb8024000) at ../migration/migration.c:1808
4 0x000055cbb6b4dfb4 in migrate_fd_cleanup_bh (opaque=0x55cbb8024000) at ../migration/migration.c:1850
5 0x000055cbb7173ac1 in aio_bh_call (bh=0x55cbb7eb98e0) at ../util/async.c:141
6 0x000055cbb7173bcb in aio_bh_poll (ctx=0x55cbb7ebba80) at ../util/async.c:169
7 0x000055cbb715ba4b in aio_dispatch (ctx=0x55cbb7ebba80) at ../util/aio-posix.c:381
8 0x000055cbb7173ffe in aio_ctx_dispatch (source=0x55cbb7ebba80, callback=0x0, user_data=0x0) at ../util/async.c:311
9 0x00007f30c9c8cdf4 in g_main_context_dispatch () at /usr/lib64/libglib-2.0.so.0
10 0x000055cbb71851a2 in glib_pollfds_poll () at ../util/main-loop.c:232
11 0x000055cbb718521c in os_host_main_loop_wait (timeout=42251070366) at ../util/main-loop.c:255
12 0x000055cbb7185321 in main_loop_wait (nonblocking=0) at ../util/main-loop.c:531
13 0x000055cbb6e6ba27 in qemu_main_loop () at ../softmmu/runstate.c:726
14 0x000055cbb6ad6fd7 in main (argc=68, argv=0x7ffc0c578888, envp=0x7ffc0c578ab0) at ../softmmu/main.c:50
To make sure that the send threads could be terminated, IO channels should be
shut down to avoid waiting IO.
Signed-off-by: Li Zhang <lizhang@suse.de>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
We were using the iov directly, but we will need this info on the
following patch.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
We will need to split it later in zero_num (number of zero pages) and
normal_num (number of normal pages). This name is better.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
We are dividing by page_size to multiply again in the only use.
Once there, improve the comments.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
