linux/kernel, branch v2.6.20

[PATCH] fork_idle() should be cpuinit, not devinit

2007-02-02T00:17:06Z

Signed-off-by: Al Viro Signed-off-by: Linus Torvalds

[PATCH] kprobes: replace magic numbers with enum

2007-01-31T00:01:35Z

Replace the magic numbers with an enum, and gets rid of a warning on the specific architectures (ex. powerpc) on which the compiler considers 'char' as 'unsigned char'. Signed-off-by: Masami Hiramatsu Cc: Prasanna S Panchamukhi Cc: Ananth N Mavinakayanahalli Cc: Anil S Keshavamurthy Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] namespaces: fix task exit disaster

2007-01-30T21:40:36Z

This is based on a patch by Eric W. Biederman, who pointed out that pid namespaces are still fake, and we only have one ever active. So for the time being, we can modify any code which could access tsk->nsproxy->pid_ns during task exit to just use &init_pid_ns instead, and move the exit_task_namespaces call in do_exit() back above exit_notify(), so that an exiting nfs server has a valid tsk->sighand to work with. Long term, pulling pid_ns out of nsproxy might be the cleanest solution. Signed-off-by: Eric W. Biederman [ Eric's patch fixed to take care of free_pid() too ] Signed-off-by: Serge E. Hallyn Signed-off-by: Linus Torvalds

Revert "[PATCH] namespaces: fix exit race by splitting exit"

2007-01-30T21:35:18Z

This reverts commit 7a238fcba0629b6f2edbcd37458bae56fcf36be5 in preparation for a better and simpler fix proposed by Eric Biederman (and fixed up by Serge Hallyn) Acked-by: Serge E. Hallyn Signed-off-by: Linus Torvalds

[PATCH] namespaces: fix exit race by splitting exit

2007-01-30T16:26:44Z

Fix exit race by splitting the nsproxy putting into two pieces. First piece reduces the nsproxy refcount. If we dropped the last reference, then it puts the mnt_ns, and returns the nsproxy as a hint to the caller. Else it returns NULL. The second piece of exiting task namespaces sets tsk->nsproxy to NULL, and drops the references to other namespaces and frees the nsproxy only if an nsproxy was passed in. A little awkward and should probably be reworked, but hopefully it fixes the NFS oops. Signed-off-by: Serge E. Hallyn Cc: Herbert Poetzl Cc: Oleg Nesterov Cc: "Eric W. Biederman" Cc: Cedric Le Goater Cc: Daniel Hokka Zakrisson Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Clear spurious irq stat information when adding irq handler

2007-01-23T22:16:31Z

Any newly added irq handler may obviously make any old spurious irq status invalid, since the new handler may well be the thing that is supposed to handle any interrupts that came in. So just clear the statistics when adding handlers. Pointed-out-by: Alan Cox Acked-by: Thomas Gleixner Acked-by: Ingo Molnar Signed-off-by: Linus Torvalds

[PATCH] notifiers: fix blocking_notifier_call_chain() scalability

2007-01-23T19:08:03Z

while lock-profiling the -rt kernel i noticed weird contention during mmap-intense workloads, and the tracer showed the following gem, in one of our MM hotpaths: threaded-2771 1.... 65us : sys_munmap (sysenter_do_call) threaded-2771 1.... 66us : profile_munmap (sys_munmap) threaded-2771 1.... 66us : blocking_notifier_call_chain (profile_munmap) threaded-2771 1.... 66us : rt_down_read (blocking_notifier_call_chain) ouch! a global rw-semaphore taken in one of the most performance- sensitive codepaths of the kernel. And i dont even have oprofile enabled! All distro kernels have CONFIG_PROFILING enabled, so this scalability problem affects the majority of Linux users. The fix is to enhance blocking_notifier_call_chain() to only take the lock if there appears to be work on the call-chain. With this patch applied i get nicely saturated system, and much higher munmap performance, on SMP systems. And as a bonus this also fixes a similar scalability bottleneck in the thread-exit codepath: profile_task_exit() ... Signed-off-by: Ingo Molnar Acked-by: Peter Zijlstra Acked-by: Nick Piggin Signed-off-by: Linus Torvalds

[PATCH] fix "kvm: add vm exit profiling"

2007-01-23T15:52:05Z

export profile_hits() on !SMP too. Cc: Ingo Molnar Cc: Avi Kivity Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] KVM: add VM-exit profiling

2007-01-12T02:18:21Z

This adds the profile=kvm boot option, which enables KVM to profile VM exits. Use: "readprofile -m ./System.map | sort -n" to see the resulting output: [...] 18246 serial_out 148.3415 18945 native_flush_tlb 378.9000 23618 serial_in 212.7748 29279 __spin_unlock_irq 622.9574 43447 native_apic_write 2068.9048 52702 enable_8259A_irq 742.2817 54250 vgacon_scroll 89.3740 67394 ide_inb 6126.7273 79514 copy_page_range 98.1654 84868 do_wp_page 86.6000 140266 pit_read 783.6089 151436 ide_outb 25239.3333 152668 native_io_delay 21809.7143 174783 mask_and_ack_8259A 783.7803 362404 native_set_pte_at 36240.4000 1688747 total 0.5009 Signed-off-by: Ingo Molnar Acked-by: Avi Kivity Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] Change cpu_up and co from devinit to cpuinit

2007-01-12T02:18:20Z

Compiling the kernel with CONFIG_HOTPLUG = y and CONFIG_HOTPLUG_CPU = n with CONFIG_RELOCATABLE = y generates the following modpost warnings WARNING: vmlinux - Section mismatch: reference to .init.data: from .text between '_cpu_up' (at offset 0xc0141b7d) and 'cpu_up' WARNING: vmlinux - Section mismatch: reference to .init.data: from .text between '_cpu_up' (at offset 0xc0141b9c) and 'cpu_up' WARNING: vmlinux - Section mismatch: reference to .init.text:__cpu_up from .text between '_cpu_up' (at offset 0xc0141bd8) and 'cpu_up' WARNING: vmlinux - Section mismatch: reference to .init.data: from .text between '_cpu_up' (at offset 0xc0141c05) and 'cpu_up' WARNING: vmlinux - Section mismatch: reference to .init.data: from .text between '_cpu_up' (at offset 0xc0141c26) and 'cpu_up' WARNING: vmlinux - Section mismatch: reference to .init.data: from .text between '_cpu_up' (at offset 0xc0141c37) and 'cpu_up' This is because cpu_up, _cpu_up and __cpu_up (in some architectures) are defined as __devinit AND __cpu_up calls some __cpuinit functions. Since __cpuinit would map to __init with this kind of a configuration, we get a .text refering .init.data warning. This patch solves the problem by converting all of __cpu_up, _cpu_up and cpu_up from __devinit to __cpuinit. The approach is justified since the callers of cpu_up are either dependent on CONFIG_HOTPLUG_CPU or are of __init type. Thus when CONFIG_HOTPLUG_CPU=y, all these cpu up functions would land up in .text section, and when CONFIG_HOTPLUG_CPU=n, all these functions would land up in .init section. Tested on a i386 SMP machine running linux-2.6.20-rc3-mm1. Signed-off-by: Gautham R Shenoy Cc: Vivek Goyal Cc: Mikael Starvik Cc: Ralf Baechle Cc: Kyle McMartin Cc: Paul Mackerras Cc: Benjamin Herrenschmidt Cc: "David S. Miller" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds