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* Merge git://git.kernel.org/pub/scm/linux/kernel/git/viro/bdevLinus Torvalds2008-10-231-10/+9
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * git://git.kernel.org/pub/scm/linux/kernel/git/viro/bdev: (66 commits) [PATCH] kill the rest of struct file propagation in block ioctls [PATCH] get rid of struct file use in blkdev_ioctl() BLKBSZSET [PATCH] get rid of blkdev_locked_ioctl() [PATCH] get rid of blkdev_driver_ioctl() [PATCH] sanitize blkdev_get() and friends [PATCH] remember mode of reiserfs journal [PATCH] propagate mode through swsusp_close() [PATCH] propagate mode through open_bdev_excl/close_bdev_excl [PATCH] pass fmode_t to blkdev_put() [PATCH] kill the unused bsize on the send side of /dev/loop [PATCH] trim file propagation in block/compat_ioctl.c [PATCH] end of methods switch: remove the old ones [PATCH] switch sr [PATCH] switch sd [PATCH] switch ide-scsi [PATCH] switch tape_block [PATCH] switch dcssblk [PATCH] switch dasd [PATCH] switch mtd_blkdevs [PATCH] switch mmc ...
| * [PATCH] switch ubdAl Viro2008-10-211-13/+12
| | | | | | | | | | | | ubd_ioctl() doesn't need BKL, so unlocked_ioctl() it becomes... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * [PATCH] beginning of methods conversionAl Viro2008-10-211-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | To keep the size of changesets sane we split the switch by drivers; to keep the damn thing bisectable we do the following: 1) rename the affected methods, add ones with correct prototypes, make (few) callers handle both. That's this changeset. 2) for each driver convert to new methods. *ALL* drivers are converted in this series. 3) kill the old (renamed) methods. Note that it _is_ a flagday; all in-tree drivers are converted and by the end of this series no trace of old methods remain. The only reason why we do that this way is to keep the damn thing bisectable and allow per-driver debugging if anything goes wrong. New methods: open(bdev, mode) release(disk, mode) ioctl(bdev, mode, cmd, arg) /* Called without BKL */ compat_ioctl(bdev, mode, cmd, arg) locked_ioctl(bdev, mode, cmd, arg) /* Called with BKL, legacy */ Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | x86: Fix ASM_X86__ header guardsH. Peter Anvin2008-10-221-2/+2
| | | | | | | | | | | | | | | | | | Change header guards named "ASM_X86__*" to "_ASM_X86_*" since: a. the double underscore is ugly and pointless. b. no leading underscore violates namespace constraints. Signed-off-by: H. Peter Anvin <hpa@zytor.com>
* | x86, um: get rid of uml-config.hAl Viro2008-10-223-16/+17
| | | | | | | | | | | | | | Take a few symbols we need into kern_constants.h Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
* | x86, um: get rid of arch/um/Kconfig.archAl Viro2008-10-225-132/+131
| | | | | | | | | | | | | | | | | | | | Teach scripts/kconfig/Makefile and top-level Makefile that arch/*/Makefile is allowed to say Kconfig := <whatever I want instead of arch/blah/Kconfig>. Rewrite arch/um/Kconfig and arch/um/Kconfig.<subarch> so that the latter would be top-level one (and include the pieces of the former). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
* | x86, um: get rid of arch/um/os symlinkAl Viro2008-10-225-25/+4
| | | | | | | | | | | | | | | | we can get DEV_NULL defined for arch/um/drivers/null.c in less convoluted ways, TYVM... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
* | x86, um: get rid of excessive includes of uml-config.hAl Viro2008-10-229-9/+0
| | | | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
* | x86, um: get rid of header symlinksAl Viro2008-10-2250-19/+5
| | | | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
* | x86, um: merge Kconfig.i386 and Kconfig.x86_64Al Viro2008-10-224-57/+23
| | | | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
* | x86, um: get rid of sysdep symlinkAl Viro2008-10-2241-10/+2
| | | | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
* | x86, um: trim the junk from uml ptrace-*.hAl Viro2008-10-222-15/+2
| | | | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
* | x86, um: take vm-flags.h to sysdepAl Viro2008-10-224-3/+2
| | | | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
* | x86, um: get rid of uml asm/archAl Viro2008-10-222-18/+2
| | | | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
* | x86, um: get rid of uml highmem.hAl Viro2008-10-224-17/+14
| | | | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
* | x86, um: get rid of uml unistd.hAl Viro2008-10-225-41/+4
| | | | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
* | x86, um: get rid of system.h -> system.h includeAl Viro2008-10-227-55/+266
| | | | | | | | | | | | | | | | Long-term we want to split system.h and include barriers part from underlying target; for now copy that part to sysdep. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
* | x86, um: uml atomic.h is not needed anymoreAl Viro2008-10-221-11/+0
| | | | | | | | | | | | | | | | Its only difference from underlying atomic.h used to be the include of kernel.h; it's not needed there anymore. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
* | x86, um: untangle uml ldt.hAl Viro2008-10-229-9/+9
| | | | | | | | | | | | | | | | | | * turn asm/ldt.h into ldt.h; update the (very few) users * take host_ldt.h into sysdep, kill symlink mess * includes of asm/arch/ldt.h turn into asm/ldt.h now Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
* | x86, um: get rid of more uml asm/arch usesAl Viro2008-10-223-3/+3
| | | | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
* | x86, um: remove dead header (uml module-generic.h; never used these days)Al Viro2008-10-221-6/+0
| | | | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
* | x86, um: get rid of uml signal.hAl Viro2008-10-221-29/+0
| | | | | | | | | | | | | | | | | | the only theoretical reason for it these days is ppc; aside of uml/ppc being dead, do_signal() would be happier in arch/powerpc/kernel/signal.h anyway. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
* | x86, um: sanitize uml sigcontext.h usesAl Viro2008-10-227-71/+2
| | | | | | | | | | | | | | | | | | | | | | | | a) the only difference between sigcontext and sysdep/sigcontext is that the former contains externs for two long-dead functions. Removed, switched the only user to sysdep/sigcontext b) asm/sigcontext.h is removable - that of underlying architecture would get used. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
* | x86, um: now we can get rid of trivial uml headersAl Viro2008-10-2260-371/+2
| | | | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
* | x86, um: ... and asm-x86 moveAl Viro2008-10-222-4/+4
| | | | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
* | x86, um: initial part of asm-um moveAl Viro2008-10-22145-8/+3699
| | | | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
* | x86, um: take arch/um/include/* out of the wayAl Viro2008-10-2279-27/+26
|/ | | | | | | | | We can't just plop asm/* into it - userland helpers are built with it in search path and seeing asm/* show up there suddenly would be a bad idea. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
* uml: fix a compile errorWANG Cong2008-10-201-1/+2
| | | | | | | | | | | | | Fix arch/um/sys-i386/signal.c: In function 'copy_sc_from_user': arch/um/sys-i386/signal.c:182: warning: dereferencing 'void *' pointer arch/um/sys-i386/signal.c:182: error: request for member '_fxsr_env' in something not a structure or union Signed-off-by: WANG Cong <wangcong@zeuux.org> Cc: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* container freezer: implement freezer cgroup subsystemMatt Helsley2008-10-201-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch implements a new freezer subsystem in the control groups framework. It provides a way to stop and resume execution of all tasks in a cgroup by writing in the cgroup filesystem. The freezer subsystem in the container filesystem defines a file named freezer.state. Writing "FROZEN" to the state file will freeze all tasks in the cgroup. Subsequently writing "RUNNING" will unfreeze the tasks in the cgroup. Reading will return the current state. * Examples of usage : # mkdir /containers/freezer # mount -t cgroup -ofreezer freezer /containers # mkdir /containers/0 # echo $some_pid > /containers/0/tasks to get status of the freezer subsystem : # cat /containers/0/freezer.state RUNNING to freeze all tasks in the container : # echo FROZEN > /containers/0/freezer.state # cat /containers/0/freezer.state FREEZING # cat /containers/0/freezer.state FROZEN to unfreeze all tasks in the container : # echo RUNNING > /containers/0/freezer.state # cat /containers/0/freezer.state RUNNING This is the basic mechanism which should do the right thing for user space task in a simple scenario. It's important to note that freezing can be incomplete. In that case we return EBUSY. This means that some tasks in the cgroup are busy doing something that prevents us from completely freezing the cgroup at this time. After EBUSY, the cgroup will remain partially frozen -- reflected by freezer.state reporting "FREEZING" when read. The state will remain "FREEZING" until one of these things happens: 1) Userspace cancels the freezing operation by writing "RUNNING" to the freezer.state file 2) Userspace retries the freezing operation by writing "FROZEN" to the freezer.state file (writing "FREEZING" is not legal and returns EIO) 3) The tasks that blocked the cgroup from entering the "FROZEN" state disappear from the cgroup's set of tasks. [akpm@linux-foundation.org: coding-style fixes] [akpm@linux-foundation.org: export thaw_process] Signed-off-by: Cedric Le Goater <clg@fr.ibm.com> Signed-off-by: Matt Helsley <matthltc@us.ibm.com> Acked-by: Serge E. Hallyn <serue@us.ibm.com> Tested-by: Matt Helsley <matthltc@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* uml: remove the dead TTY_LOG codeAdrian Bunk2008-10-163-232/+0
| | | | | | | | | | Remove the dead CONFIG_TTY_LOG (no kconfig option). Reported-by: Robert P. J. Day <rpjday@crashcourse.ca> Signed-off-by: Adrian Bunk <bunk@kernel.org> Cc: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge git://git.infradead.org/users/dwmw2/random-2.6Linus Torvalds2008-10-132-8/+3
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * git://git.infradead.org/users/dwmw2/random-2.6: Fix autoloading of MacBook Pro backlight driver. Automatic MODULE_ALIAS() for DMI match tables. Remove asm/a.out.h files for all architectures without a.out support. Introduce HAVE_AOUT symbol to remove hard-coded arch list for BINFMT_AOUT Remove redundant CONFIG_ARCH_SUPPORTS_AOUT S390: Update comments about why we don't use <asm-generic/statfs.h> SPARC: Use <asm-generic/statfs.h> PowerPC: Use <asm-generic/statfs.h> PARISC: Use <asm-generic/statfs.h> x86_64: Use <asm-generic/statfs.h> IA64: Use <asm-generic/statfs.h> ARM: Use <asm-generic/statfs.h> Make <asm-generic/statfs.h> suitable for 64-bit platforms. Define and use PCI_DEVICE_ID_MARVELL_88ALP01_CCIC for CAFÉ camera driver [MTD] [NAND] Define and use PCI_DEVICE_ID_MARVELL_88ALP01_NAND for CAFÉ Use PCI_DEVICE_ID_88ALP01 for CAFÉ chip, rather than PCI_DEVICE_ID_CAFE. EFS: Don't set f_fsid in statfs().
| * Merge branch 'master' of ↵David Woodhouse2008-10-133-2/+7
| |\ | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6 Conflicts: include/asm-x86/statfs.h
| * | Introduce HAVE_AOUT symbol to remove hard-coded arch list for BINFMT_AOUTDavid Woodhouse2008-09-061-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | HAVE_AOUT doesn't quite do the same thing as the recently removed ARCH_SUPPORTS_AOUT config option. That was set even on platforms where binfmt_aout isn't supported, although it's not entirely clear why. So it's best just to introduce a new symbol, handled consistently with other similar HAVE_xxx symbols; with a simple 'select' in the arch Kconfig. Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
| * | Remove redundant CONFIG_ARCH_SUPPORTS_AOUTDavid Woodhouse2008-09-062-6/+0
| | | | | | | | | | | | | | | | | | We don't need this any more; arguably we never really did. Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
* | | uml: small cleanups and note bugs to be dealt with by uml authors...Alan Cox2008-10-131-0/+2
| |/ |/| | | | | | | Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | Merge phase #4 (X2APIC, APIC unification, CPU identification unification) of ↵Linus Torvalds2008-10-111-2/+2
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'x86-v28-for-linus-phase4-D' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (186 commits) x86, debug: print more information about unknown CPUs x86 setup: handle more than 8 CPU flag words x86: cpuid, fix typo x86: move transmeta cap read to early_init_transmeta() x86: identify_cpu_without_cpuid v2 x86: extended "flags" to show virtualization HW feature in /proc/cpuinfo x86: move VMX MSRs to msr-index.h x86: centaur_64.c remove duplicated setting of CONSTANT_TSC x86: intel.c put workaround for old cpus together x86: let intel 64-bit use intel.c x86: make intel_64.c the same as intel.c x86: make intel.c have 64-bit support code x86: little clean up of intel.c/intel_64.c x86: make 64 bit to use amd.c x86: make amd_64 have 32 bit code x86: make amd.c have 64bit support code x86: merge header in amd_64.c x86: add srat_detect_node for amd64 x86: remove duplicated force_mwait x86: cpu make amd.c more like amd_64.c v2 ...
| * | x86_64: uml: fix rename header guardHiroshi Shimamoto2008-08-151-2/+2
| |/ | | | | | | | | | | | | | | | | | | In unistd_64.h, the guard macro _ASM_X86_64_UNISTD_H_ is renamed to ASM_X86__UNISTD_64_H. This change should be applied to arch/um/sys-x86_64/syscall_table.c. Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | Merge branch 'for-linus' of git://git.alsa-project.org/alsa-kernelLinus Torvalds2008-10-111-0/+4
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 'for-linus' of git://git.alsa-project.org/alsa-kernel: (258 commits) ALSA: hda: VREF powerdown for headphones ALSA: hda: STAC_HP_M4 ALSA: ASoC: Check for machine type in GTA01 machine driver ALSA: mtpav - Fix race in probe ALSA: usb-audio: dynamic detection of MIDI interfaces in uaxx-quirk ALSA: Add a note on dependency of RTC stuff ALSA: ASoC: add new param mux to dapm_mux_update_power ALSA: Increase components array size ALSA: ASoC: Correct inverted Mic PGA Switch control in wm8510 driver ALSA: hda: comment typo fix ALSA: hda: comment typo fix ALSA: hda - Fix PCI SSID for ASROCK K18N78FullHD-hSLI ALSA: snd-usb-audio: support for Edirol UA-4FX device ALSA: usb - Fix possible Oops at USB-MIDI disconnection ALSA: hda - Fix another ALC889A (rev 0x100101) ALSA: hda: add more board-specific information for Realtek ALC662 rev1 ALSA: Correct Vladimir Barinov's e-mail address ALSA: cs46xx: Add PCI IDs for TerraTec and Hercules cards ALSA: hda: SPDIF stream muting support ALSA: hda: appletv support ...
| * | sound: make OSS sound core optionalTejun Heo2008-08-291-0/+4
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | sound/sound_core.c implements soundcore.ko and contains two parts - sound_class which is shared by both ALSA and OSS and device redirection support for OSS. It's always compiled when any sound support is enabled although it's necessary only when OSS (the actual one or emulation) is enabled. This is slightly wasteful and as device redirection always registers character device region for major 14, it prevents alternative implementation. This patch introduces a new config SOUND_OSS_CORE which is selected iff OSS support is actually necessary and build the OSS core part conditionally. If OSS is disabled, soundcore merely contains sound_class but leaving it that way seems to be the simplest approach as otherwise sound_class should be in ALSA core file if OSS is disabled but should be in soundcore if OSS is enabled. Also, there's also the user confusion factor. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Jaroslav Kysela <perex@perex.cz>
* | kernel/cpu.c: create a CPU_STARTING cpu_chain notifierManfred Spraul2008-09-081-0/+1
|/ | | | | | | | | | | | | | | | | Right now, there is no notifier that is called on a new cpu, before the new cpu begins processing interrupts/softirqs. Various kernel function would need that notification, e.g. kvm works around by calling smp_call_function_single(), rcu polls cpu_online_map. The patch adds a CPU_STARTING notification. It also adds a helper function that sends the message to all cpu_chain handlers. Tested on x86-64. All other archs are untested. Especially on sparc, I'm not sure if I got it right. Signed-off-by: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* uml: fix tty-related build errorWANG Cong2008-07-301-13/+1
| | | | | | | | | | | | /home/wangcong/Projects/linux-2.6/arch/um/drivers/line.c: In function `line_write_interrupt': /home/wangcong/Projects/linux-2.6/arch/um/drivers/line.c:366: error: `struct tty_ldisc' has no member named `write_wakeup' /home/wangcong/Projects/linux-2.6/arch/um/drivers/line.c:367: error: `struct tty_ldisc' has no member named `write_wakeup' Signed-off-by: WANG Cong <wangcong@zeuux.org> Cc: Jeff Dike <jdike@addtoit.com> Acked-by: Alan Cox <alan@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* um: use generic show_mem()Johannes Weiner2008-07-261-31/+0
| | | | | | | | | | | | | | | | | Remove arch-specific show_mem() in favor of the generic version. This also removes the following redundant information display: - free swap pages, printed by show_swap_cache_info() - pages in swapcache, printed by show_swap_cache_info() where show_mem() calls show_free_areas(), which calls show_swap_cache_info(). Signed-off-by: Johannes Weiner <hannes@saeurebad.de> Acked-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'timers-fixes-for-linus' of ↵Linus Torvalds2008-07-241-1/+1
|\ | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: nohz: adjust tick_nohz_stop_sched_tick() call of s390 as well nohz: prevent tick stop outside of the idle loop
| * Merge branch 'linus' into timers/nohzIngo Molnar2008-07-1818-27/+76
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| * | nohz: prevent tick stop outside of the idle loopThomas Gleixner2008-07-181-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Jack Ren and Eric Miao tracked down the following long standing problem in the NOHZ code: scheduler switch to idle task enable interrupts Window starts here ----> interrupt happens (does not set NEED_RESCHED) irq_exit() stops the tick ----> interrupt happens (does set NEED_RESCHED) return from schedule() cpu_idle(): preempt_disable(); Window ends here The interrupts can happen at any point inside the race window. The first interrupt stops the tick, the second one causes the scheduler to rerun and switch away from idle again and we end up with the tick disabled. The fact that it needs two interrupts where the first one does not set NEED_RESCHED and the second one does made the bug obscure and extremly hard to reproduce and analyse. Kudos to Jack and Eric. Solution: Limit the NOHZ functionality to the idle loop to make sure that we can not run into such a situation ever again. cpu_idle() { preempt_disable(); while(1) { tick_nohz_stop_sched_tick(1); <- tell NOHZ code that we are in the idle loop while (!need_resched()) halt(); tick_nohz_restart_sched_tick(); <- disables NOHZ mode preempt_enable_no_resched(); schedule(); preempt_disable(); } } In hindsight we should have done this forever, but ... /me grabs a large brown paperbag. Debugged-by: Jack Ren <jack.ren@marvell.com>, Debugged-by: eric miao <eric.y.miao@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* | | UML: make several more things staticWANG Cong2008-07-2413-23/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Make some variables and functions static, since they don't need to be global. - Remove an unused function - arch/um/kernel/time.c::sched_clock(). - Clean the style a bit as complained by checkpatch.pl. Cc: Jeff Dike <jdike@addtoit.com> Signed-off-by: WANG Cong <wangcong@zeuux.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | arch/um/kernel/mem.c: remove arch_validate()WANG Cong2008-07-242-33/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Remove arch_validate(), because no one uses it. - Remove useless macro HAVE_ARCH_VALIDATE. - Make the variable 'empty_bad_page' static. Cc: Jeff Dike <jdike@addtoit.com> Signed-off-by: WANG Cong <wangcong@zeuux.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | arch/um/kernel/irq.c: clean up some functionsWANG Cong2008-07-243-37/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make activate_fd() and free_irq_by_irq_and_dev() static. Remove init_aio_irq() since it has no users. Cc: Jeff Dike <jdike@addtoit.com> Signed-off-by: WANG Cong <wangcong@zeuux.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | UML - Fix boot crashJeff Dike2008-07-231-0/+8
| |/ |/| | | | | | | | | | | | | | | | | | | | | | | My copying of linux/init.h didn't go far enough. The definition of __used singled out gcc minor version 3, but didn't care what the major version was. This broke when unit-at-a-time was added and gcc started throwing out initcalls. This results in an early boot crash when ptrace tries to initialize a process with an empty, uninitialized register set. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | Merge branch 'generic-ipi' into generic-ipi-for-linusIngo Molnar2008-07-151-2/+1
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: arch/powerpc/Kconfig arch/s390/kernel/time.c arch/x86/kernel/apic_32.c arch/x86/kernel/cpu/perfctr-watchdog.c arch/x86/kernel/i8259_64.c arch/x86/kernel/ldt.c arch/x86/kernel/nmi_64.c arch/x86/kernel/smpboot.c arch/x86/xen/smp.c include/asm-x86/hw_irq_32.h include/asm-x86/hw_irq_64.h include/asm-x86/mach-default/irq_vectors.h include/asm-x86/mach-voyager/irq_vectors.h include/asm-x86/smp.h kernel/Makefile Signed-off-by: Ingo Molnar <mingo@elte.hu>
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