virtio allows drivers to suppress callbacks (ie. interrupts) for
efficiency (no locking, it's just an optimization).
There's a similar mechanism for the host to suppress notifications
coming from the guest: in that case, we ignore the suppression if the
ring is completely full.
It turns out that life is simpler if the host similarly ignores
callback suppression when the ring is completely empty: the network
driver wants to free up old packets in a timely manner, and otherwise
has to use a timer to poll.
We have to remove the code which ignores interrupts when the driver
has disabled them (again, it had no locking and hence was unreliable
anyway).
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Since commit 72e61eb40b (virtio: change config
to guest endian) config space is no longer fixed endian.
Lets change the virtio_blk_config variables.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Rusty,
This patch is a prereq for the virtio_blk blocksize patch, please apply it
first.
Adding an u32 value to the virtio_blk_config unconvered a small bug the config
space defintions:
v is a pointer, to we have to use sizeof(*v) instead of sizeof(v).
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Hello Rusty,
seems that we still have a problem with virtio_net and the enable_cb callback.
During a long running network stress tests with virtio and got the following
oops:
------------[ cut here ]------------
kernel BUG at drivers/virtio/virtio_ring.c:230!
illegal operation: 0001 [#1] SMP
Modules linked in:
CPU: 0 Not tainted 2.6.26-rc2-kvm-00436-gc94c08b-dirty #34
Process netserver (pid: 2582, task: 000000000fbc4c68, ksp: 000000000f42b990)
Krnl PSW : 0704c00180000000 00000000002d0ec8 (vring_enable_cb+0x1c/0x60)
R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 CC:0 PM:0 EA:3
Krnl GPRS: 0000000000000000 0000000000000000 000000000ef3d000 0000000010009800
0000000000000000 0000000000419ce0 0000000000000080 000000000000007b
000000000adb5538 000000000ef40900 000000000ef40000 000000000ef40920
0000000000000000 0000000000000005 000000000029c1b0 000000000fea7d18
Krnl Code: 00000000002d0ebc: a7110001 tmll %r1,1
00000000002d0ec0: a7740004 brc 7,2d0ec8
00000000002d0ec4: a7f40001 brc 15,2d0ec6
>00000000002d0ec8: a517fffe nill %r1,65534
00000000002d0ecc: 40103000 sth %r1,0(%r3)
00000000002d0ed0: 07f0 bcr 15,%r0
00000000002d0ed2: e31020380004 lg %r1,56(%r2)
00000000002d0ed8: a7480000 lhi %r4,0
Call Trace:
([<000000000029c0fc>] virtnet_poll+0x290/0x3b8)
[<0000000000333fb8>] net_rx_action+0x9c/0x1b8
[<00000000001394bc>] __do_softirq+0x74/0x108
[<000000000010d16a>] do_softirq+0x92/0xac
[<0000000000139826>] irq_exit+0x72/0xc8
[<000000000010a7b6>] do_extint+0xe2/0x104
[<0000000000110508>] ext_no_vtime+0x16/0x1a
Last Breaking-Event-Address:
[<00000000002d0ec4>] vring_enable_cb+0x18/0x60
I looked into the virtio_net code for some time and I think the following
scenario happened. Please look at virtnet_poll:
[...]
/* Out of packets? */
if (received < budget) {
netif_rx_complete(vi->dev, napi);
if (unlikely(!vi->rvq->vq_ops->enable_cb(vi->rvq))
&& napi_schedule_prep(napi)) {
vi->rvq->vq_ops->disable_cb(vi->rvq);
__netif_rx_schedule(vi->dev, napi);
goto again;
}
}
If an interrupt arrives after netif_rx_complete, a second poll routine can run
on a different cpu. The second check for napi_schedule_prep would prevent any
harm in the network stack, but we have called enable_cb possibly after the
disable_cb in skb_recv_done.
static void skb_recv_done(struct virtqueue *rvq)
{
struct virtnet_info *vi = rvq->vdev->priv;
/* Schedule NAPI, Suppress further interrupts if successful. */
if (netif_rx_schedule_prep(vi->dev, &vi->napi)) {
rvq->vq_ops->disable_cb(rvq);
__netif_rx_schedule(vi->dev, &vi->napi);
}
}
That means that the second poll routine runs with interrupts enabled, which is
ok, since we can handle additional interrupts. The problem is now that the
second poll routine might also call enable_cb, triggering the BUG.
The only solution I can come up with, is to remove the BUG statement in
enable_cb - similar to disable_cb. Opinions or better ideas where the oops
could come from?
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Note that by itself, having a "hardware" random generator does very
little: you should probably run "rngd" in your guest to feed this into
the kernel entropy pool.
Included:
virtio_rng: dont use vmalloced addresses for virtio
If virtio_rng is build as a module, random_data is an address
in vmalloc space. As virtio expects guest real addresses, this
can cause any kind of funny behaviour, so lets allocate
random_data dynamically with kmalloc.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Hello Rusty,
sometimes it is useful to share a disk (e.g. usr). To avoid file system
corruption, the disk should be mounted read-only in that case. This patch
adds a new feature flag, that allows the host to specify, if the disk should
be considered read-only.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Anthony Liguori points out that three different transports use the virtio code,
but each one keeps its own counter to set the virtio_device's index field. In
theory (though not in current practice) this means that names could be
duplicated, and that risk grows as more transports are created.
So we move the selection of the unique virtio_device.index into the common code
in virtio.c, which has the side-benefit of removing duplicate code.
The only complexity is that lguest and S/390 use the index to uniquely identify
the device in case of catastrophic failure before register_virtio_device() is
called: now we use the offset within the descriptor page as a unique identifier
for the printks.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Carsten Otte <cotte@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Chris Lalancette <clalance@redhat.com>
Cc: Anthony Liguori <anthony@codemonkey.ws>
The common virtio code sets the bus_id, overriding anything virtio_pci
sets anyway.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Carsten Otte <cotte@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Chris Lalancette <clalance@redhat.com>
Cc: Anthony Liguori <anthony@codemonkey.ws>
Chris Lalancette <clalance@redhat.com> points out that virtio.c sets all device
names to '0', '1', etc, which looks silly in /proc/interrupts. We change this
from '%d' to 'virtio%d'.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Carsten Otte <cotte@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Chris Lalancette <clalance@redhat.com>
Cc: Anthony Liguori <anthony@codemonkey.ws>
Fix a modprobe virtio_blk ; rmmod virtio_blk ; modprobe virtio_blk crash; this
was basically because we weren't doing "del_gendisk()" in the remove path.
Signed-off-by: Chris Lalancette <clalance@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (moved del_gendisk up)
Thanks to Jon Corbet & LWN. Only took me a day to join the dots.
Host->Guest netcat before (with unnecessily large receive buffers):
1073741824 bytes (1.1 GB) copied, 24.7528 seconds, 43.4 MB/s
After:
1073741824 bytes (1.1 GB) copied, 17.6369 seconds, 60.9 MB/s
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
> +#define ARCH_KMALLOC_MINALIGN (sizeof(long) * 2)
> +#define ARCH_SLAB_MINALIGN (sizeof(long) * 2)
This doesn't work if SLAB is selected and slab debugging is enabled as
these are passed to the preprocessor, and the preprocessor doesn't
understand sizeof.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'for-linus' of git://git.kernel.dk/linux-2.6-block:
cfq-iosched: fix RCU problem in cfq_cic_lookup()
block: make blktrace use per-cpu buffers for message notes
Added in elevator switch message to blktrace stream
Added in MESSAGE notes for blktraces
block: reorder cfq_queue to save space on 64bit builds
block: Move the second call to get_request to the end of the loop
splice: handle try_to_release_page() failure
splice: fix sendfile() issue with relay
Specify the minimum slab/kmalloc alignment to be 8 bytes. This fixes a
crash when SLOB is selected as the memory allocator. The FRV arch needs
this so that it can use the load- and store-double instructions without
faulting. By default SLOB sets the minimum to be 4 bytes.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix a typo in the header guard of asm/ipc.h.
Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
cfq_cic_lookup() needs to properly protect ioc->ioc_data before
dereferencing it and also exclude updaters of ioc->ioc_data as well.
Also add a number of comments documenting why the existing RCU usage
is OK.
Thanks a lot to "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> for
review and comments!
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Currently it uses a single static char array, but that risks
being corrupted when multiple users issue message notes at the
same time. Make the buffers dynamically allocated when the trace
is setup and make them per-cpu instead.
The default max message size of 1k is also very large, the
interface is mainly for small text notes. So shrink it to 128 bytes.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Allows messages to be inserted into blktrace streams.
Signed-off-by: Alan D. Brunelle <alan.brunelle@hp.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
saves 8 bytes of padding & increases objects/slab from 30 to 32 on my
AMD64 config
Signed-off-by: Richard Kennedy <richard@rsk.demon.co.uk>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
In function get_request_wait, the second call to get_request could be
moved to the end of the while loop, because if the first call to
get_request fails, the second call will fail without sleep.
Signed-off-by: Zhang Yanmin <yanmin.zhang@intel.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
splice currently assumes that try_to_release_page() always suceeds,
but it can return failure. If it does, we cannot steal the page.
Acked-by: Mingming Cao <cmm@us.ibm.com
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Splice isn't always incrementing the ppos correctly, which broke
relay splice.
Signed-off-by: Tom Zanussi <zanussi@comcast.net>
Tested-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6:
pciehp: add message about pciehp_slot_with_bus option
pci hotplug core: add check of duplicate slot name
pciehp: move msleep after power off
pciehp: poll cmd completion if hotplug interrupt is disabled
pciehp: fix slow probing
pciehp: fix NULL dereference in interrupt handler
shpchp: add message about shpchp_slot_with_bus option
PCI: don't enable ASPM on devices with mixed PCIe/PCI functions
Some (broken?) platform assign the same slot name to multiple hotplug
slots. On such system, slot initialization would fail because of name
collision. The pciehp driver already have a "slot_with_bus" module
option which adds the bus number into the slot name. This patch adds
the message about this module option that will be displayed when slot
name collision is detected.
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Fix the following errors reported by Jan C. Nordholz in
http://bugzilla.kernel.org/show_bug.cgi?id=10751.
kobject_add_internal failed for 2 with -EEXIST, don't try to register things with the same name in the same directory.
Pid: 1, comm: swapper Tainted: G W 2.6.26-rc3 #1
[<c0266980>] kobject_add_internal+0x140/0x190
[<c0266afd>] kobject_init_and_add+0x2d/0x40
[<c027bc91>] pci_hp_register+0x81/0x2f0
[<c027fd07>] pciehp_probe+0x1a7/0x470
[<c01b3b84>] sysfs_add_one+0x44/0xa0
[<c01b3c1f>] sysfs_addrm_start+0x3f/0xb0
[<c01b497a>] sysfs_create_link+0x8a/0xf0
[<c0279570>] pcie_port_probe_service+0x50/0x80
[<c02e0545>] driver_sysfs_add+0x55/0x70
[<c02e0662>] driver_probe_device+0x82/0x180
[<c02e07cc>] __driver_attach+0x6c/0x70
[<c02dfe0a>] bus_for_each_dev+0x3a/0x60
[<c05db2d0>] pcied_init+0x0/0x80
[<c02e04e6>] driver_attach+0x16/0x20
[<c02e0760>] __driver_attach+0x0/0x70
[<c02e0341>] bus_add_driver+0x1a1/0x220
[<c05db2d0>] pcied_init+0x0/0x80
[<c02e09cd>] driver_register+0x4d/0x120
[<c05db050>] ibm_acpiphp_init+0x0/0x190
[<c0125aab>] printk+0x1b/0x20
[<c05db2d0>] pcied_init+0x0/0x80
[<c05db2de>] pcied_init+0xe/0x80
[<c05c751a>] kernel_init+0x10a/0x300
[<c0120138>] schedule_tail+0x18/0x50
[<c0103b9a>] ret_from_fork+0x6/0x1c
[<c05c7410>] kernel_init+0x0/0x300
[<c05c7410>] kernel_init+0x0/0x300
[<c010485b>] kernel_thread_helper+0x7/0x1c
=======================
pci_hotplug: Unable to register kobject '2'<3>pciehp: pci_hp_register failed with error -22
Slot with the same name can be registered multiple times if shpchp or
pciehp driver is loaded after acpiphp is loaded because ACPI based
hotplug driver and Native OS hotplug driver trying to handle the same
physical slot. In this case, current pci_hotplug core will call
kobject_init_and_add() muliple time with the same name. This is the
cause of this problem. To fix this problem, this patch adds the check
into pci_hp_register() to see if the slot with the same name.
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
According to the PCI Express specification, we must wait for at least
1 second after turning power off before taking any action that relies
on power having been removed from the slot/adapter. For this, current
pciehp wait for 1 second after issuing the power off command in
hpc_power_off_slot() function. But waiting for 1 second in
hpc_power_off_slot() can make pciehp probing slow-down because pciehp
probe code calls hpc_power_off_slot() if the slot is not occupied just
in case. We don't need to wait for 1 second at the pciehp probe time
because there is no action on that empty slot. So move 1 second wait
from hpc_power_off_slot() to the caller of hpc_power_off_slot().
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Fix improper long wait for command completion in pciehp probing.
As described in PCI Express specification, software notification is
not generated if the command that occurs as a result of a write to the
Slot Control register that disables software notification of command
completed events. Since pciehp driver doesn't take it into account,
such command is issued in pciehp probing, and it causes improper long
wait for command completion.
This patch changes the pciehp driver to take such command into
account.
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Fix the "pciehp probing slow" problem reported from Jan C. Nordholz in
http://bugzilla.kernel.org/show_bug.cgi?id=10751.
The command completed bit in Slot Status register applies only to
commands issued to control the attention indicator, power indicator,
power controller, or electromechanical interlock. However, writes to
other parts of the Slot Control register would end up writing to the
control fields. Hence, any write to Slot Control register is
considered as a command. However, if the controller doesn't support
any of attention indicator, power indicator, power controller and
electromechanical interlock, command completed bit would not set in
writing to Slot Control register. In this case, we should not wait for
command completed bit set, otherwise all commands would be considered
not completed in timeout seconds (1 sec.).
The cause of the problem is pciehp driver didn't take this situation
into account. This patch changes pciehp to take it into account. This
patch also add the check for "No Command Completed Support" bit in
Slot Capability register. If it is set, we should not wait for command
completed bit set as well.
This problem seems to be revealed by the commit
c27fb883df that fixed the bug that
pciehp did not wait for command completed properly (pciehp just
ignored the command completion event).
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Some (broken?) platform assign the same slot name to multiple hotplug
slots. On such system, slot initialization would fail because of name
collision. The shpchp driver already have a "slot_with_bus" module
option which adds the bus number into the slot name. This patch adds
the message about this module option that will be displayed when slot
name collision is detected.
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
There's a reason why using C99 initialisers even in the supposedly
trivial structs is a good idea.
Signed-off-by: Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006@gmx.net>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Move the AP7 cpufreq init to late_initcall() so that we don't try to
bring up cpufreq until the governor is ready. x86 also uses
late_initcall() for this.
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Based on Roland's patch. This approach was suggested by Austin Clements
from the very beginning, and then by Linus.
As Austin pointed out, the execing task can be killed by SI_TIMER signal
because exec flushes the signal handlers, but doesn't discard the pending
signals generated by posix timers. Perhaps not a bug, but people find this
surprising. See http://bugzilla.kernel.org/show_bug.cgi?id=10460
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Austin Clements <amdragon+kernelbugzilla@mit.edu>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently sigqueue_free() removes sigqueue from list, but doesn't cancel the
pending signal. This is not consistent, the task should either receive the
"full" signal along with siginfo_t, or it shouldn't receive the signal at all.
Change sigqueue_free() to clear SIGQUEUE_PREALLOC but leave sigqueue on list
if it is queued.
This is a user-visible change. If the signal is blocked, it stays queued
after sys_timer_delete() until unblocked with the "stale" si_code/si_value,
and of course it is still counted wrt RLIMIT_SIGPENDING which also limits
the number of posix timers.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Austin Clements <amdragon+kernelbugzilla@mit.edu>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6.26:
sh: Drop broken URAM support on SH7723.
sh: update Migo-R defconfig
sh: use sm501 8250 mfd support on r2d boards
sh: add probe support for new sh7723 cut
sh: fix VPU interrupt vector for sh7723
sh: fix USBF resource for sh7722
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (52 commits)
vlan: Use bitmask of feature flags instead of seperate feature bits
fmvj18x_cs: add NextCom NC5310 rev B support
xirc2ps_cs: re-initialize the multicast address in do_reset
3C509: rx_bytes should not be increased when alloc_skb failed
NETFRONT: Use __skb_queue_purge()
VIRTIO: Use __skb_queue_purge()
phylib: do EXPORT_SYMBOL on get_phy_id
netlink: Fix nla_parse_nested_compat() to call nla_parse() directly
WAN: protect HDLC proto list while insmod/rmmod
drivers/net/fs_enet: remove null pointer dereference
S2io: Version update for napi and MSI-X patches
S2io: Added napi support when MSIX is enabled.
S2io: Move all the transmit completions to a single msi-x (alarm) vector
drivers/net/ehea - remove unnecessary memset after kzalloc
au1000_eth: remove useless check
Blackfin EMAC Driver: Removed duplicated include <linux/ethtool.h>
cpmac bugfixes and enhancements
e1000e: use resource_size_t, not unsigned long, for phys addrs
net/usb: add support for Apple USB Ethernet Adapter
uli526x: add support for netpoll
...
Align i2c_device_id.driver_data to 8 bytes to not fail on crossbuilds.
(Added in d2653e92732bd3911feff6bee5e23dbf959381db.)
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
The tuner driver used to change i2c_client.name for its own needs, but
it really shouldn't, as this field is used by i2c-core to do the
device/driver matching. So, create and use a separate field for the
tuner driver needs.
Signed-off-by: Michael Krufky <mkrufky@linuxtv.org>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Just provide reasonable defaults for the new stuff. Tickless and
hrtimers are turned on for all boards except ATSTK1004.
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
global_reg_snapshot shouldn't be visible in our userspace headers.
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This was copied over from the previous MobileR bits, which doesn't
apply to R2. The URAM block on R2 is recycled for the L2 instead.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
