Commit Graph

40 Commits

Author SHA1 Message Date
aliguori
7a11b22eab fix raw_aio_remove (Stefano Stabellini)
Hi all,
this small patch fixes a bug in the list iteration of raw_aio_remove.
Cheers,

Stefano

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6644 c046a42c-6fe2-441c-8c8c-71466251a162
2009-02-26 16:40:19 +00:00
aliguori
3ec88e8036 block: remove error handling from qemu_malloc() callers (Avi Kivity)
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6527 c046a42c-6fe2-441c-8c8c-71466251a162
2009-02-05 22:05:53 +00:00
aliguori
22bf14582a fix raw_aio_read\write error handling (Stefano Stabellini)
Currently when qemu_paio_read or qemu_paio_write return an error we call
qemu_aio_release without removing the request from the list.
I know that in the current implementation qemu_paio_write\read don't return
any error, but still the behavior is wrong, especially considering
that the implementation of these two functions is likely to change in is
the future.
This patch fixes the problem adding a raw_aio_remove function that
removes the callback from the queue and also calls qemu_aio_release.
raw_aio_remove is called by raw_aio_read, raw_aio_write and
raw_aio_cancel.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6470 c046a42c-6fe2-441c-8c8c-71466251a162
2009-01-29 17:02:08 +00:00
blueswir1
55f11ca3c2 Rename sigev_signo to avoid FreeBSD problems (Juergen Lock)
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6414 c046a42c-6fe2-441c-8c8c-71466251a162
2009-01-24 11:54:21 +00:00
blueswir1
c9db92fcc1 Use kill instead of sigqueue: re-enables AIO on OpenBSD
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6360 c046a42c-6fe2-441c-8c8c-71466251a162
2009-01-17 06:49:15 +00:00
aliguori
31b1a7b4f5 global s/fflush(logfile)/qemu_log_flush()/ (Eduardo Habkost)
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>



git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6339 c046a42c-6fe2-441c-8c8c-71466251a162
2009-01-15 22:35:09 +00:00
aliguori
93fcfe39a0 Convert references to logfile/loglevel to use qemu_log*() macros
This is a large patch that changes all occurrences of logfile/loglevel
global variables to use the new qemu_log*() macros.

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>



git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6338 c046a42c-6fe2-441c-8c8c-71466251a162
2009-01-15 22:34:14 +00:00
aliguori
4141d4c251 Return -errno on write failure (Gleb Natapov)
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>



git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@6324 c046a42c-6fe2-441c-8c8c-71466251a162
2009-01-15 20:44:26 +00:00
aliguori
3c529d9359 Replace posix-aio with custom thread pool
glibc implements posix-aio as a thread pool and imposes a number of limitations.

1) it limits one request per-file descriptor.  we hack around this by dup()'ing
file descriptors which is hideously ugly

2) it's impossible to add new interfaces and we need a vectored read/write
operation to properly support a zero-copy API.

What has been suggested to me by glibc folks, is to implement whatever new
interfaces we want and then it can eventually be proposed for standardization.
This requires that we implement our own posix-aio implementation though.

This patch implements posix-aio using pthreads.  It immediately eliminates the
need for fd pooling.

It performs at least as well as the current posix-aio code (in some
circumstances, even better).

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>



git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5996 c046a42c-6fe2-441c-8c8c-71466251a162
2008-12-12 16:41:40 +00:00
aliguori
e20e830bbd block: make raw aio signaling non-blocking (Gerd Hoffman)
This patch switches the read handle of the signaling pipe into
non-blocking mode.  This avoids unwanted blocking reads and also
allows to read all bytes out of the signaling pipe in case we got
signaled more that once before the handler ran.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>



git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5716 c046a42c-6fe2-441c-8c8c-71466251a162
2008-11-13 19:23:17 +00:00
aliguori
7ab064d2b5 Fix previous commit (spotted by Robert Riebisch).
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>



git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5487 c046a42c-6fe2-441c-8c8c-71466251a162
2008-10-14 18:14:47 +00:00
aliguori
f646557804 Define O_DSYNC as O_SYNC if necessary.
O_DSYNC isn't available on OS X.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>



git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5486 c046a42c-6fe2-441c-8c8c-71466251a162
2008-10-14 18:00:38 +00:00
aliguori
9f7965c7e9 Expand cache= option and use write-through caching by default
This patch changes the cache= option to accept none, writeback, or writethough
to control the host page cache behavior.  By default, writethrough caching is
now used which internally is implemented by using O_DSYNC to open the disk
images.  When using -snapshot, writeback is used by default since data integrity
it not at all an issue.

cache=none has the same behavior as cache=off previously.  The later syntax is
still supported by now deprecated.  I also cleaned up the O_DIRECT
implementation to avoid many of the #ifdefs.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>



git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5485 c046a42c-6fe2-441c-8c8c-71466251a162
2008-10-14 14:42:54 +00:00
aliguori
9e472e101f Fix IO performance regression in sparc
Replace signalfd with signal handler/pipe.  There is no way to interrupt
the CPU execution loop when a file descriptor becomes readable.  This
results in a large performance regression in sparc emulation during
bootup.
   
This patch switches us to signal handler/pipe which was originally
suggested by Ian Jackson.  The signal handler lets us interrupt the
CPU emulation loop while the write to a pipe lets us avoid the
select/signal race condition.
    
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>



git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5451 c046a42c-6fe2-441c-8c8c-71466251a162
2008-10-08 19:50:24 +00:00
blueswir1
674a24acf7 Fix warning about missing return value
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5405 c046a42c-6fe2-441c-8c8c-71466251a162
2008-10-03 19:00:40 +00:00
aliguori
27463101f1 Make compatfd fallback more robust
Be more friendly when signalfd() fails, and also add configure checks to detect
that syscall(SYS_signalfd) actually works.  malc pointed out that some installs
do not have /usr/include/linux headers that are in sync with the glibc headers
so why SYS_signalfd is defined, it's #defined to _NR_signalfd which is not
defined in the /usr/include/linux header.

While this is a distro bug, it doesn't hurt to do a more thorough job in
detection.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>



git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5334 c046a42c-6fe2-441c-8c8c-71466251a162
2008-09-27 20:58:43 +00:00
aliguori
acce87f92b Really fix the BSD build this time
struct aioinit isn't defined on BSD it appears so we need to guard everything
in an #if defined(__linux__).

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>



git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5325 c046a42c-6fe2-441c-8c8c-71466251a162
2008-09-26 16:12:14 +00:00
aliguori
0d0ab49ab0 Fix build on non-Linux unices
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>



git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5324 c046a42c-6fe2-441c-8c8c-71466251a162
2008-09-26 16:04:40 +00:00
aliguori
5353872545 Implement an fd pool to get real AIO with posix-aio
This patch implements a simple fd pool to allow many AIO requests with
posix-aio.  The result is significantly improved performance (identical to that
reported for linux-aio) for both cache=on and cache=off.

The fundamental problem with posix-aio is that it limits itself to one thread
per-file descriptor.  I don't know why this is, but this patch provides a simple
mechanism to work around this (duplicating the file descriptor).

This isn't a great solution, but it seems like a reasonable intermediate step
between posix-aio and a custom thread-pool to replace it.

Ryan Harper will be posting some performance analysis he did comparing posix-aio
with fd pooling against linux-aio.  The size of the posix-aio thread pool and
the fd pool were largely determined by him based on this analysis.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>



git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5323 c046a42c-6fe2-441c-8c8c-71466251a162
2008-09-26 15:59:29 +00:00
aliguori
997306fc22 Fix build on FreeBSD
__GLIBC_PREREQ is defined in such a way that the ! cannot be used in front of
it on FreeBSD.  Also, -lpthread is not implied by the build and we definitely
use it for compatfd support.

While at it, I added a default initialization for posix-aio that seems to
perform well in our testing.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>



git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5322 c046a42c-6fe2-441c-8c8c-71466251a162
2008-09-26 15:52:17 +00:00
aliguori
828899865f Relax posix-aio restrictions on newer glibcs
RedHat 9 shipped glibc 2.3.  Modern versions of glibc do not have the aio thread
exit issue that the comment references.  This patch adjusts the check to only
limit aio_init on glibc versions < 2.4.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>



git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5304 c046a42c-6fe2-441c-8c8c-71466251a162
2008-09-23 02:57:00 +00:00
aliguori
a76bab4952 Refactor AIO to allow multiple AIO implementations
This patch refactors the AIO layer to allow multiple AIO implementations.  It's
only possible because of the recent signalfd() patch.  

Right now, the AIO infrastructure is pretty specific to the block raw backend.
For other block devices to implement AIO, the qemu_aio_wait function must
support registration.  This patch introduces a new function,
qemu_aio_set_fd_handler, which can be used to register a file descriptor to be
called back.  qemu_aio_wait() now polls a set of file descriptors registered
with this function until one becomes readable or writable.

This patch should allow the implementation of alternative AIO backends (via a
thread pool or linux-aio) and AIO backends in non-traditional block devices
(like NBD).

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>



git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5297 c046a42c-6fe2-441c-8c8c-71466251a162
2008-09-22 19:17:18 +00:00
aliguori
ad02ad6fda Do not allow AIO to be inited multiple times
This prevents two signalfd() threads from being spawned.  This problem was
originally spotted by Blue Swirl.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>



git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5289 c046a42c-6fe2-441c-8c8c-71466251a162
2008-09-22 14:49:01 +00:00
aliguori
2acf5af04d block-raw is not a protocol
The protocol_name "file" was added to the block driver when async IO was
introduced.  This can be used to select that a file is treated as a raw
device instead of probing for the type.  However, protocols are not subject
to path interpretation which cases qcow2 images with raw base images to not
function is the path was specified relatively.

The fix is simply to remove the protocol_name from the raw block driver.  The
proper way to force the use of a raw block format is to use the format= option
with -drive.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>



git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5233 c046a42c-6fe2-441c-8c8c-71466251a162
2008-09-16 13:21:58 +00:00
aliguori
08af02e25b Make sure to define fd_open when not on Linux
My previous commit broke the build.  This was spotted by C.W. Betts.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>



git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5231 c046a42c-6fe2-441c-8c8c-71466251a162
2008-09-15 16:48:11 +00:00
aliguori
03ff3ca30f Use common objects for qemu-img and qemu-nbd
Right now, we sprinkle #if defined(QEMU_IMG) && defined(QEMU_NBD) all over the
code.  It's ugly and causes us to have to build multiple object files for
linking against qemu and the tools.

This patch introduces a new file, qemu-tool.c which contains enough for
qemu-img, qemu-nbd, and QEMU to all share the same objects.

This also required getting qemu-nbd to be a bit more Windows friendly.  I also
changed the Windows block-raw to use normal IO instead of overlapping IO since
we don't actually do AIO yet on Windows.  I changed the various #if 0's to
 #if WIN32_AIO to make it easier for someone to eventually fix AIO on Windows.

After this patch, there are no longer any #ifdef's related to qemu-img and
qemu-nbd.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>



git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5226 c046a42c-6fe2-441c-8c8c-71466251a162
2008-09-15 15:51:35 +00:00
aliguori
a3392f9b10 Only build compatfd when using AIO and make sure to always init AIO
OpenBSD doesn't use AIO so don't try to build compatfd when not using AIO.

Also make sure to call qemu_aio_init() from bdrv_init.  Everything that uses
bdrv calls bdrv_init so it makes sense to init aio from there instead of
in every single tool.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>



git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5197 c046a42c-6fe2-441c-8c8c-71466251a162
2008-09-11 18:00:19 +00:00
aliguori
2c41a5f9e3 Make sure to read siginfo from signalfd
Otherwise, we'll idle at 100% cpu.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>



git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5195 c046a42c-6fe2-441c-8c8c-71466251a162
2008-09-11 14:32:27 +00:00
aliguori
baf35cb902 Use signalfd() to work around signal/select race
This patch introduces signalfd() to work around the signal/select race in
checking for AIO completions.  For platforms that don't support signalfd(), we
emulate it with threads.

There was a long discussion about this approach.  I don't believe there are any
fundamental problems with this approach and I believe eliminating the use of
signals is a good thing.

I've tested Windows and Linux using Windows and Linux guests.  I've also checked
for disk IO performance regressions.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>



git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5187 c046a42c-6fe2-441c-8c8c-71466251a162
2008-09-10 15:45:19 +00:00
blueswir1
543952ca93 Add missing FreeBSD #include (Juergen Lock)
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5081 c046a42c-6fe2-441c-8c8c-71466251a162
2008-08-24 10:43:12 +00:00
blueswir1
128ab2ff50 Preliminary OpenBSD host support (based on OpenBSD patches by Todd T. Fries)
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5012 c046a42c-6fe2-441c-8c8c-71466251a162
2008-08-15 18:33:42 +00:00
blueswir1
414f0dab09 Use AIO only if host supports it (based on OpenBSD patches by Todd T. Fries)
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5010 c046a42c-6fe2-441c-8c8c-71466251a162
2008-08-15 18:20:52 +00:00
ths
2f7264888a Add a parameter to disable host cache, by Laurent Vivier.
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@4836 c046a42c-6fe2-441c-8c8c-71466251a162
2008-07-03 11:47:46 +00:00
bellard
bed5cc5207 Align file accesses with cache=off (O_DIRECT) (Kevin Wolf, Laurent Vivier)
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@4599 c046a42c-6fe2-441c-8c8c-71466251a162
2008-05-28 09:51:09 +00:00
blueswir1
6dd2db52a9 Revert 4367
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@4377 c046a42c-6fe2-441c-8c8c-71466251a162
2008-05-07 15:26:22 +00:00
blueswir1
adcbebaa40 Align file accesses with cache=off (Kevin Wolf, Laurent Vivier)
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@4367 c046a42c-6fe2-441c-8c8c-71466251a162
2008-05-06 17:26:59 +00:00
bellard
01534fe901 restore original values for ai.aio_threads and ai.aio_num
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@3896 c046a42c-6fe2-441c-8c8c-71466251a162
2008-01-06 18:53:07 +00:00
ths
985a03b0ce Real SCSI device passthrough (v4), by Laurent Vivier.
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@3851 c046a42c-6fe2-441c-8c8c-71466251a162
2007-12-24 16:10:43 +00:00
balrog
33f002714b Add "cache" parameter to "-drive" (Laurent Vivier).
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@3848 c046a42c-6fe2-441c-8c8c-71466251a162
2007-12-24 14:33:24 +00:00
ths
223d4670a0 Split block-raw.c into block-raw-posix.c and block-raw-win32.c, by
Anthony Liguori.


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@3814 c046a42c-6fe2-441c-8c8c-71466251a162
2007-12-15 17:28:36 +00:00