linux/kernel/cpuset.c, branch v2.6.23

usermodehelper: Tidy up waiting

2007-07-18T15:47:40Z

Rather than using a tri-state integer for the wait flag in call_usermodehelper_exec, define a proper enum, and use that. I've preserved the integer values so that any callers I've missed should still work OK. Signed-off-by: Jeremy Fitzhardinge Cc: James Bottomley Cc: Randy Dunlap Cc: Christoph Hellwig Cc: Andi Kleen Cc: Paul Mackerras Cc: Johannes Berg Cc: Ralf Baechle Cc: Bjorn Helgaas Cc: Joel Becker Cc: Tony Luck Cc: Kay Sievers Cc: Srivatsa Vaddagiri Cc: Oleg Nesterov Cc: David Howells

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/avi/kvm

2007-07-17T18:50:26Z

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/avi/kvm: (80 commits) KVM: Use CPU_DYING for disabling virtualization KVM: Tune hotplug/suspend IPIs KVM: Keep track of which cpus have virtualization enabled SMP: Allow smp_call_function_single() to current cpu i386: Allow smp_call_function_single() to current cpu x86_64: Allow smp_call_function_single() to current cpu HOTPLUG: Adapt thermal throttle to CPU_DYING HOTPLUG: Adapt cpuset hotplug callback to CPU_DYING HOTPLUG: Add CPU_DYING notifier KVM: Clean up #includes KVM: Remove kvmfs in favor of the anonymous inodes source KVM: SVM: Reliably detect if SVM was disabled by BIOS KVM: VMX: Remove unnecessary code in vmx_tlb_flush() KVM: MMU: Fix Wrong tlb flush order KVM: VMX: Reinitialize the real-mode tss when entering real mode KVM: Avoid useless memory write when possible KVM: Fix x86 emulator writeback KVM: Add support for in-kernel pio handlers KVM: VMX: Fix interrupt checking on lightweight exit KVM: Adds support for in-kernel mmio handlers ...

Reduce cpuset.c write_lock_irq() to read_lock()

2007-07-16T16:05:43Z

cpuset.c:update_nodemask() uses a write_lock_irq() on tasklist_lock to block concurrent forks; a read_lock() suffices and is less intrusive. Signed-off-by: Paul Menage Acked-by: Paul Jackson Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

HOTPLUG: Adapt cpuset hotplug callback to CPU_DYING

2007-07-16T09:05:49Z

CPU_DYING is called in atomic context, so don't try to take any locks. Signed-off-by: Avi Kivity

cpuset: zero malloc - fix for old cpusets

2007-06-16T20:16:15Z

The cpuset code to present a list of tasks using a cpuset to user space could write to an array that it had kmalloc'd, after a kmalloc request of zero size. The problem was that the code didn't check for writes past the allocated end of the array until -after- the first write. This is a race condition that is likely rare -- it would only show up if a cpuset went from being empty to having a task in it, during the brief time between the allocation and the first write. Prior to roughly 2.6.22 kernels, this was also a benign problem, because a zero kmalloc returned a few usable bytes anyway, and no harm was done with the bogus write. With the 2.6.22 kernel changes to make issue a warning if code tries to write to the location returned from a zero size allocation, this problem is no longer benign. This cpuset code would occassionally trigger that warning. The fix is trivial -- check before storing into the array, not after, whether the array is big enough to hold the store. Cc: "Eric W. Biederman" Cc: "Serge E. Hallyn" Cc: Balbir Singh Cc: Dave Hansen Cc: Herbert Poetzl Cc: Kirill Korotaev Cc: Paul Menage Cc: Srivatsa Vaddagiri Cc: Christoph Lameter Signed-off-by: Paul Jackson Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

use simple_read_from_buffer in kernel/

2007-05-09T19:30:49Z

Cleanup using simple_read_from_buffer() for /dev/cpuset/tasks and /proc/config.gz. Cc: Paul Jackson Cc: Randy Dunlap Signed-off-by: Akinobu Mita Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

cpusets: allow empty {cpus,mems}_allowed to be set for unpopulated cpuset

2007-05-08T18:15:14Z

You currently cannot remove all cpus or mems from cpus_allowed or mems_allowed of a cpuset. We now allow both if there are no attached tasks. Acked-by: Paul Jackson Cc: Christoph Lameter Signed-off-by: Paul Menage Signed-off-by: David Rientjes Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

header cleaning: don't include smp_lock.h when not used

2007-05-08T18:15:07Z

Remove includes of where it is not used/needed. Suggested by Al Viro. Builds cleanly on x86_64, i386, alpha, ia64, powerpc, sparc, sparc64, and arm (all 59 defconfigs). Signed-off-by: Randy Dunlap Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Fix race between attach_task and cpuset_exit

2007-05-08T18:15:05Z

Currently cpuset_exit() changes the exiting task's ->cpuset pointer w/o taking task_lock(). This can lead to ugly races between attach_task and cpuset_exit. Details of the races are described at http://lkml.org/lkml/2007/3/24/132. Patch below closes those races. Signed-off-by: Srivatsa Vaddagiri Cc: Paul Jackson Cc: Balbir Singh Cc: Paul Menage Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

cpusets: allow TIF_MEMDIE threads to allocate anywhere

2007-05-07T19:12:53Z

OOM killed tasks have access to memory reserves as specified by the TIF_MEMDIE flag in the hopes that it will quickly exit. If such a task has memory allocations constrained by cpusets, we may encounter a deadlock if a blocking task cannot exit because it cannot allocate the necessary memory. We allow tasks that have the TIF_MEMDIE flag to allocate memory anywhere, including outside its cpuset restriction, so that it can quickly die regardless of whether it is __GFP_HARDWALL. Cc: Andi Kleen Cc: Paul Jackson Cc: Christoph Lameter Signed-off-by: David Rientjes Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds