Srivatsa S. Bhat
43ea953649
xen, balloon: Fix CPU hotplug callback registration ...
Subsystems that want to register CPU hotplug callbacks, as well as perform
initialization for the CPUs that are already online, often do it as shown
below:
get_online_cpus();
for_each_online_cpu(cpu)
init_cpu(cpu);
register_cpu_notifier(&foobar_cpu_notifier);
put_online_cpus();
This is wrong, since it is prone to ABBA deadlocks involving the
cpu_add_remove_lock and the cpu_hotplug.lock (when running concurrently
with CPU hotplug operations).
The xen balloon driver doesn't take get/put_online_cpus() around this code,
but that is also buggy, since it can miss CPU hotplug events in between the
initialization and callback registration:
for_each_online_cpu(cpu)
init_cpu(cpu);
^
| Race window; Can miss CPU hotplug events here.
v
register_cpu_notifier(&foobar_cpu_notifier);
Interestingly, the balloon code in xen can simply be reorganized as shown
below, to have a race-free method to register hotplug callbacks, without even
taking get/put_online_cpus(). This is because the initialization performed for
already online CPUs is exactly the same as that performed for CPUs that come
online later. Moreover, the code has checks in place to avoid double
initialization.
register_cpu_notifier(&foobar_cpu_notifier);
get_online_cpus();
for_each_online_cpu(cpu)
init_cpu(cpu);
put_online_cpus();
A hotplug operation that occurs between registering the notifier and calling
get_online_cpus(), won't disrupt anything, because the code takes care to
perform the memory allocations only once.
So reorganize the balloon code in xen this way to fix the issues with CPU
hotplug callback registration.
Cc: Konrad Rzeszutek Wilk <[email protected] >
Cc: David Vrabel <[email protected] >
Cc: Ingo Molnar <[email protected] >
Reviewed-by: Boris Ostrovsky <[email protected] >
Signed-off-by: Srivatsa S. Bhat <[email protected] >
Signed-off-by: Rafael J. Wysocki <[email protected] >
2014-03-20 13:43:48 +01:00
ACPI / sleep: Add extra checks for HW Reduced ACPI mode sleep states
2014-03-13 22:11:39 +01:00
Merge branch 'for-3.14-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/libata
2014-03-10 12:56:24 -07:00
drivers/base/topology.c: Fix CPU hotplug callback registration
2014-03-20 13:43:45 +01:00
Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus
2014-01-30 17:20:32 -08:00
Merge branch 'for-linus' of git://git.kernel.dk/linux-block
2014-03-07 09:59:44 -08:00
drivers: bus: fix CCI driver kcalloc call parameters swap
2014-01-31 15:15:13 -08:00
Merge branch 'for-3.14/drivers' of git://git.kernel.dk/linux-block
2014-01-30 11:40:10 -08:00
Char/Misc fixes for 3.14-rc3
2014-02-14 16:13:00 -08:00
Single fix for a clock driver merged in 3.14-rc1. Without this fix the
2014-03-08 10:51:30 -08:00
clocksource, dummy-timer: Fix CPU hotplug callback registration
2014-03-20 13:43:45 +01:00
acpi-cpufreq: Fix CPU hotplug callback registration
2014-03-20 13:43:45 +01:00
powerpc/powernv/cpuidle: Back-end cpuidle driver for powernv platform.
2014-01-29 17:02:24 +11:00
crypto/nx/nx-842: Fix handling of vmalloc addresses
2014-02-11 11:24:49 +11:00
Merge branches 'pm-cpufreq' and 'pm-devfreq'
2014-01-29 11:48:23 +01:00
Merge branch 'fixes' of git://git.infradead.org/users/vkoul/slave-dma
2014-03-01 21:30:43 -06:00
i7300_edac: Fix device reference count
2014-02-25 09:43:13 +01:00
ASoC: dapm: Add locking to snd_soc_dapm_xxxx_pin functions
2014-02-20 18:40:07 +09:00
Merge branch 'for-3.14-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
2014-03-08 11:51:13 -08:00
firmware/google: drop 'select EFI' to avoid recursive dependency
2014-01-27 21:02:40 -08:00
drivers/fmc/fmc-write-eeprom.c: fix decimal permissions
2014-02-25 15:25:43 -08:00
gpio: tb10x: GPIO_TB10X needs to select GENERIC_IRQ_CHIP
2014-02-05 11:13:59 +01:00
Merge tag 'ttm-fixes-3.14-2014-03-12' of git://people.freedesktop.org/~thomash/linux into drm-fixes
2014-03-13 17:31:24 +10:00
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid
2014-02-18 16:29:46 -08:00
Drivers: hv: vmbus: Don't timeout during the initial connection with host
2014-02-07 08:27:34 -08:00
hwmon, via-cputemp: Fix CPU hotplug callback registration
2014-03-20 13:43:48 +01:00
i2c: Remove usage of orphaned symbol OF_I2C
2014-03-13 22:33:44 +01:00
drivers: ide: Include appropriate header file in ide-pio-blacklist.c
2014-01-28 23:35:09 -08:00
intel-idle: Fix CPU hotplug callback registration
2014-03-20 13:43:46 +01:00
iio:gyro: bug on L3GD20H gyroscope support
2014-02-18 10:24:49 +00:00
Merge git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending
2014-03-09 13:50:14 -07:00
ASoC: dapm: Add locking to snd_soc_dapm_xxxx_pin functions
2014-02-20 18:40:07 +09:00
drivers/iommu/omap-iommu-debug.c: fix decimal permissions
2014-02-25 15:25:42 -08:00
irq-metag*: stop set_affinity vectoring to offline cpus
2014-02-25 22:35:06 +00:00
isdn/hisax: hex vs decimal typo in prfeatureind()
2014-02-06 21:18:06 -08:00
Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/cooloney/linux-leds
2014-01-28 18:53:01 -08:00
Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc
2014-01-27 21:11:26 -08:00
dm cache: fix access beyond end of origin device
2014-03-12 13:52:00 -04:00
[media] adv7842: Composite free-run platfrom-data fix
2014-02-04 06:46:10 -02:00
drivers/memstick/host/rtsx_pci_ms.c: fix ms card data transfer bug
2014-01-23 16:37:04 -08:00
drivers/message/i2o/i2o_config.c: fix deadlock in compat_ioctl(I2OGETIOPS)
2014-02-10 16:01:40 -08:00
sound fixes for 3.14-rc4
2014-02-21 09:55:32 -08:00
mm: fix GFP_THISNODE callers and clarify
2014-03-10 17:26:19 -07:00
Fix uses of dma_max_pfn() when converting to a limiting address
2014-02-17 23:08:41 +00:00
Just a single fix for the UBI module unload path which makes sure we do not
2014-02-27 10:36:50 -08:00
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
2014-03-13 20:38:36 -07:00
Device tree compatible match order bug fix
2014-02-21 14:35:05 -08:00
oprofile, nmi-timer: Fix CPU hotplug callback registration
2014-03-20 13:43:46 +01:00
PCI: Don't check resource_size() in pci_bus_alloc_resource()
2014-03-12 11:19:20 -06:00
phy: let phy_provider_register be the last step in registering PHY
2014-02-18 12:13:16 -08:00
ARM: SoC fixes for 3.14-rc
2014-03-09 19:27:31 -07:00
platform/chrome: Cleanups and improvements
2014-01-29 20:06:01 -08:00
PNP / ACPI: proper handling of ACPI IO/Memory resource parsing failures
2014-03-11 21:22:10 +01:00
Few fixes:
2014-02-14 10:32:28 -08:00
powercap, intel-rapl: Fix CPU hotplug callback registration
2014-03-20 13:43:44 +01:00
pwm: lp3943: Fix potential memory leak during request
2014-02-26 15:45:12 +01:00
rapidio/tsi721: fix tasklet termination in dma channel release
2014-03-04 07:55:49 -08:00
regulator: Fixes for v3.14-rc5
2014-03-04 08:41:42 -08:00
drivers/rtc/rtc-s3c.c: fix incorrect way of save/restore of S3C2410_TICNT for TYPE_S3C64XX
2014-03-04 07:55:48 -08:00
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
2014-03-04 08:44:32 -08:00
Sparc: sparc_cpu_model isn't in asm/system.h any more [ver #2 ]
2014-02-20 13:34:11 -05:00
scsi, fcoe: Fix CPU hotplug callback registration
2014-03-20 13:43:45 +01:00
Merge remote-tracking branches 'spi/fix/ath79', 'spi/fix/atmel', 'spi/fix/coldfire', 'spi/fix/fsl-dspi', 'spi/fix/imx' and 'spi/fix/topcliff-pch' into spi-linus
2014-03-07 11:08:13 +08:00
Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus
2014-01-30 17:20:32 -08:00
staging/cxt1e1/linux.c: Correct arbitrary memory write in c4_ioctl()
2014-03-04 16:20:01 -08:00
Target/sbc: Fix sbc_copy_prot for offset scatters
2014-03-06 20:52:11 -08:00
thermal, x86-pkg-temp: Fix CPU hotplug callback registration
2014-03-20 13:43:47 +01:00
Revert "tty: Set correct tty name in 'active' sysfs attribute"
2014-02-22 14:31:04 -08:00
Revert "xhci 1.0: Limit arbitrarily-aligned scatter gather."
2014-03-07 11:48:13 -08:00
mm: close PageTail race
2014-03-04 07:55:47 -08:00
Merge git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending
2014-03-01 21:33:09 -06:00
video: Kconfig: Allow more broad selection of the imxfb framebuffer driver.
2014-02-14 10:44:52 +02:00
VME: Correct read/write alignment algorithm
2014-02-07 08:16:14 -08:00
drivers/w1/masters/w1-gpio.c: add strong pullup emulation
2014-01-23 16:37:04 -08:00
octeon, watchdog: Fix CPU hotplug callback registration
2014-03-20 13:43:46 +01:00
xen, balloon: Fix CPU hotplug callback registration
2014-03-20 13:43:48 +01:00
43ea953649