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* i386: prepare shared kernel/process.cThomas Gleixner2007-10-11
| | | | | Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* x86: Make Alt-SysRq-p display the debug register contentsAlan Stern2007-07-21
| | | | | | | | | | | This patch (as921) adds code to the show_regs() routine in i386 and x86_64 to print the contents of the debug registers along with all the others. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* make seccomp zerocost in scheduleAndrea Arcangeli2007-07-16
| | | | | | | | | | | | This follows a suggestion from Chuck Ebbert on how to make seccomp absolutely zerocost in schedule too. The only remaining footprint of seccomp is in terms of the bzImage size that becomes a few bytes (perhaps even a few kbytes) larger, measure it if you care in the embedded. Signed-off-by: Andrea Arcangeli <andrea@cpushare.com> Cc: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* SLUB: i386 supportChristoph Lameter2007-05-12
| | | | | | | | | | | | | | SLUB cannot run on i386 at this point because i386 uses the page->private and page->index field of slab pages for the pgd cache. Make SLUB run on i386 by replacing the pgd slab cache with a quicklist. Limit the changes as much as possible. Leave the improvised linked list in place etc etc. This has been working here for a couple of weeks now. Acked-by: William Lee Irwin III <wli@holomorphy.com> Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* header cleaning: don't include smp_lock.h when not usedRandy Dunlap2007-05-08
| | | | | | | | | | | | Remove includes of <linux/smp_lock.h> 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 <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] i386: Convert PDA into the percpu sectionJeremy Fitzhardinge2007-05-02
| | | | | | | | | | | | | | | | | | | | | | | | Currently x86 (similar to x84-64) has a special per-cpu structure called "i386_pda" which can be easily and efficiently referenced via the %fs register. An ELF section is more flexible than a structure, allowing any piece of code to use this area. Indeed, such a section already exists: the per-cpu area. So this patch: (1) Removes the PDA and uses per-cpu variables for each current member. (2) Replaces the __KERNEL_PDA segment with __KERNEL_PERCPU. (3) Creates a per-cpu mirror of __per_cpu_offset called this_cpu_off, which can be used to calculate addresses for this CPU's variables. (4) Simplifies startup, because %fs doesn't need to be loaded with a special segment at early boot; it can be deferred until the first percpu area is allocated (or never for UP). The result is less code and one less x86-specific concept. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Andi Kleen <ak@suse.de> Cc: Andi Kleen <ak@suse.de>
* [PATCH] i386: i386 separate hardware-defined TSS from Linux additionsRusty Russell2007-05-02
| | | | | | | | | | | | | | | | | | | On Thu, 2007-03-29 at 13:16 +0200, Andi Kleen wrote: > Please clean it up properly with two structs. Not sure about this, now I've done it. Running it here. If you like it, I can do x86-64 as well. == lguest defines its own TSS struct because the "struct tss_struct" contains linux-specific additions. Andi asked me to split the struct in processor.h. Unfortunately it makes usage a little awkward. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andi Kleen <ak@suse.de>
* [PATCH] x86: Don't use MWAIT on AMD Family 10Andi Kleen2007-05-02
| | | | | | | | | | | It doesn't put the CPU into deeper sleep states, so it's better to use the standard idle loop to save power. But allow to reenable it anyways for benchmarking. I also removed the obsolete idle=halt on i386 Cc: andreas.herrmann@amd.com Signed-off-by: Andi Kleen <ak@suse.de>
* Revert "[PATCH] i386: add idle notifier"Linus Torvalds2007-02-26
| | | | | | | | | | | | | | | | | | | | | This reverts commit 2ff2d3d74705d34ab71b21f54634fcf50d57bdd5. Uwe Bugla reports that he cannot mount a floppy drive any more, and Jiri Slaby bisected it down to this commit. Benjamin LaHaise also points out that this is a big hot-path, and that interrupt delivery while idle is very common and should not go through all these expensive gyrations. Fix up conflicts in arch/i386/kernel/apic.c and arch/i386/kernel/irq.c due to other unrelated irq changes. Cc: Stephane Eranian <eranian@hpl.hp.com> Cc: Andi Kleen <ak@suse.de> Cc: Andrew Morton <akpm@osdl.org> Cc: Uwe Bugla <uwe.bugla@gmx.de> Cc: Jiri Slaby <jirislaby@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] i386 prepare for dyntickIngo Molnar2007-02-16
| | | | | | | | | | | | Prepare i386 for dyntick: idle handler callbacks. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: john stultz <johnstul@us.ibm.com> Cc: Roman Zippel <zippel@linux-m68k.org> Cc: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [PATCH] i386: add idle notifierStephane Eranian2007-02-13
| | | | | | | | | | | | | | | | Add a notifier mechanism to the low level idle loop. You can register a callback function which gets invoked on entry and exit from the low level idle loop. The low level idle loop is defined as the polling loop, low-power call, or the mwait instruction. Interrupts processed by the idle thread are not considered part of the low level loop. The notifier can be used to measure precisely how much is spent in useless execution (or low power mode). The perfmon subsystem uses it to turn on/off monitoring. Signed-off-by: stephane eranian <eranian@hpl.hp.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Andi Kleen <ak@suse.de>
* [PATCH] i386: iOPL handling for paravirt guestsZachary Amsden2007-02-13
| | | | | | | | | | | | | | | I found a clever way to make the extra IOPL switching invisible to non-paravirt compiles - since kernel_rpl is statically defined to be zero there, and only non-zero rpl kernel have a problem restoring IOPL, as popf does not restore IOPL flags unless run at CPL-0. Signed-off-by: Zachary Amsden <zach@vmware.com> Signed-off-by: Andi Kleen <ak@suse.de> Cc: Andi Kleen <ak@suse.de> Cc: Jeremy Fitzhardinge <jeremy@xensource.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Chris Wright <chrisw@sous-sol.org> Signed-off-by: Andrew Morton <akpm@osdl.org>
* [PATCH] i386: paravirt CPU hypercall batching modeZachary Amsden2007-02-13
| | | | | | | | | | | | | | | | | | | | | | | | | | The VMI ROM has a mode where hypercalls can be queued and batched. This turns out to be a significant win during context switch, but must be done at a specific point before side effects to CPU state are visible to subsequent instructions. This is similar to the MMU batching hooks already provided. The same hooks could be used by the Xen backend to implement a context switch multicall. To explain a bit more about lazy modes in the paravirt patches, basically, the idea is that only one of lazy CPU or MMU mode can be active at any given time. Lazy MMU mode is similar to this lazy CPU mode, and allows for batching of multiple PTE updates (say, inside a remap loop), but to avoid keeping some kind of state machine about when to flush cpu or mmu updates, we just allow one or the other to be active. Although there is no real reason a more comprehensive scheme could not be implemented, there is also no demonstrated need for this extra complexity. Signed-off-by: Zachary Amsden <zach@vmware.com> Signed-off-by: Andi Kleen <ak@suse.de> Cc: Andi Kleen <ak@suse.de> Cc: Jeremy Fitzhardinge <jeremy@xensource.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Chris Wright <chrisw@sous-sol.org> Signed-off-by: Andrew Morton <akpm@osdl.org>
* [PATCH] i386: Convert i386 PDA code to use %fsJeremy Fitzhardinge2007-02-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | Convert the PDA code to use %fs rather than %gs as the segment for per-processor data. This is because some processors show a small but measurable performance gain for reloading a NULL segment selector (as %fs generally is in user-space) versus a non-NULL one (as %gs generally is). On modern processors the difference is very small, perhaps undetectable. Some old AMD "K6 3D+" processors are noticably slower when %fs is used rather than %gs; I have no idea why this might be, but I think they're sufficiently rare that it doesn't matter much. This patch also fixes the math emulator, which had not been adjusted to match the changed struct pt_regs. [frederik.deweerdt@gmail.com: fixit with gdb] [mingo@elte.hu: Fix KVM too] Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Andi Kleen <ak@suse.de> Cc: Ian Campbell <Ian.Campbell@XenSource.com> Acked-by: Ingo Molnar <mingo@elte.hu> Acked-by: Zachary Amsden <zach@vmware.com> Cc: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: Frederik Deweerdt <frederik.deweerdt@gmail.com> Signed-off-by: Andrew Morton <akpm@osdl.org>
* [PATCH] sched: fix bad missed wakeups in the i386, x86_64, ia64, ACPI and ↵Ingo Molnar2006-12-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | APM idle code Fernando Lopez-Lezcano reported frequent scheduling latencies and audio xruns starting at the 2.6.18-rt kernel, and those problems persisted all until current -rt kernels. The latencies were serious and unjustified by system load, often in the milliseconds range. After a patient and heroic multi-month effort of Fernando, where he tested dozens of kernels, tried various configs, boot options, test-patches of mine and provided latency traces of those incidents, the following 'smoking gun' trace was captured by him: _------=> CPU# / _-----=> irqs-off | / _----=> need-resched || / _---=> hardirq/softirq ||| / _--=> preempt-depth |||| / ||||| delay cmd pid ||||| time | caller \ / ||||| \ | / IRQ_19-1479 1D..1 0us : __trace_start_sched_wakeup (try_to_wake_up) IRQ_19-1479 1D..1 0us : __trace_start_sched_wakeup <<...>-5856> (37 0) IRQ_19-1479 1D..1 0us : __trace_start_sched_wakeup (c01262ba 0 0) IRQ_19-1479 1D..1 0us : resched_task (try_to_wake_up) IRQ_19-1479 1D..1 0us : __spin_unlock_irqrestore (try_to_wake_up) ... <idle>-0 1...1 11us!: default_idle (cpu_idle) ... <idle>-0 0Dn.1 602us : smp_apic_timer_interrupt (c0103baf 1 0) ... <...>-5856 0D..2 618us : __switch_to (__schedule) <...>-5856 0D..2 618us : __schedule <<idle>-0> (20 162) <...>-5856 0D..2 619us : __spin_unlock_irq (__schedule) <...>-5856 0...1 619us : trace_stop_sched_switched (__schedule) <...>-5856 0D..1 619us : trace_stop_sched_switched <<...>-5856> (37 0) what is visible in this trace is that CPU#1 ran try_to_wake_up() for PID:5856, it placed PID:5856 on CPU#0's runqueue and ran resched_task() for CPU#0. But it decided to not send an IPI that no CPU - due to TS_POLLING. But CPU#0 never woke up after its NEED_RESCHED bit was set, and only rescheduled to PID:5856 upon the next lapic timer IRQ. The result was a 600+ usecs latency and a missed wakeup! the bug turned out to be an idle-wakeup bug introduced into the mainline kernel this summer via an optimization in the x86_64 tree: commit 495ab9c045e1b0e5c82951b762257fe1c9d81564 Author: Andi Kleen <ak@suse.de> Date: Mon Jun 26 13:59:11 2006 +0200 [PATCH] i386/x86-64/ia64: Move polling flag into thread_info_status During some profiling I noticed that default_idle causes a lot of memory traffic. I think that is caused by the atomic operations to clear/set the polling flag in thread_info. There is actually no reason to make this atomic - only the idle thread does it to itself, other CPUs only read it. So I moved it into ti->status. the problem is this type of change: if (!hlt_counter && boot_cpu_data.hlt_works_ok) { - clear_thread_flag(TIF_POLLING_NRFLAG); + current_thread_info()->status &= ~TS_POLLING; smp_mb__after_clear_bit(); while (!need_resched()) { local_irq_disable(); this changes clear_thread_flag() to an explicit clearing of TS_POLLING. clear_thread_flag() is defined as: clear_bit(flag, &ti->flags); and clear_bit() is a LOCK-ed atomic instruction on all x86 platforms: static inline void clear_bit(int nr, volatile unsigned long * addr) { __asm__ __volatile__( LOCK_PREFIX "btrl %1,%0" hence smp_mb__after_clear_bit() is defined as a simple compile barrier: #define smp_mb__after_clear_bit() barrier() but the explicit TS_POLLING clearing introduced by the patch: + current_thread_info()->status &= ~TS_POLLING; is not an atomic op! So the clearing of the TS_POLLING bit is freely reorderable with the reading of the NEED_RESCHED bit - and both now reside in different memory addresses. CPU idle wakeup very much depends on ordered memory ops, the clearing of the TS_POLLING flag must always be done before we test need_resched() and hit the idle instruction(s). [Symmetrically, the wakeup code needs to set NEED_RESCHED before it tests the TS_POLLING flag, so memory ordering is paramount.] Fernando's dual-core Athlon64 system has a sufficiently advanced memory ordering model so that it triggered this scenario very often. ( And it also turned out that the reason why these latencies never triggered on my testsystems is that i routinely use idle=poll, which was the only idle variant not affected by this bug. ) The fix is to change the smp_mb__after_clear_bit() to an smp_mb(), to act as an absolute barrier between the TS_POLLING write and the NEED_RESCHED read. This affects almost all idling methods (default, ACPI, APM), on all 3 x86 architectures: i386, x86_64, ia64. Signed-off-by: Ingo Molnar <mingo@elte.hu> Tested-by: Fernando Lopez-Lezcano <nando@ccrma.Stanford.EDU> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] i386: remove IOPL check on task switchChuck Ebbert2006-12-06
| | | | | | | | IOPL is implicitly saved and restored on task switch, so explicit check is no longer needed. Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com> Signed-off-by: Andi Kleen <ak@suse.de>
* [PATCH] x86: Don't use nested idle loopsAndi Kleen2006-12-06
| | | | | | | | | | | | | | | | | | | | Currently the idle loop has two nested loops -- one high level in cpu_idle and in some low level idle functions another one. Looping in the low level idle functions breaks the idle notifiers because interrupts waking up sleep states need to execute exit_idle() which is only in cpu_idle(). So don't do that, only loop in cpu_idle(). This only removes code. In some cases e.g. poll_idle the idle loop is a little longer now because cpu_idle checks more things. I hope that isn't a problem ACPI idle doesn't change behaviour because it never looped anyways. Cc: len.brown@intel.com Cc: eranian@hpl.hp.com Signed-off-by: Andi Kleen <ak@suse.de>
* [PATCH] i386: Implement "current" with the PDAJeremy Fitzhardinge2006-12-06
| | | | | | | | | | | | | Use the pcurrent field in the PDA to implement the "current" macro. This ends up compiling down to a single instruction to get the current task. Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Andi Kleen <ak@suse.de> Cc: Chuck Ebbert <76306.1226@compuserve.com> Cc: Zachary Amsden <zach@vmware.com> Cc: Jan Beulich <jbeulich@novell.com> Cc: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org>
* [PATCH] i386: Fix places where using %gs changes the usermode ABIJeremy Fitzhardinge2006-12-06
| | | | | | | | | | | | | | There are a few places where the change in struct pt_regs and the use of %gs affect the userspace ABI. These are primarily debugging interfaces where thread state can be inspected or extracted. Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Andi Kleen <ak@suse.de> Cc: Chuck Ebbert <76306.1226@compuserve.com> Cc: Zachary Amsden <zach@vmware.com> Cc: Jan Beulich <jbeulich@novell.com> Cc: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org>
* [PATCH] i386: Use %gs as the PDA base-segment in the kernelJeremy Fitzhardinge2006-12-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch is the meat of the PDA change. This patch makes several related changes: 1: Most significantly, %gs is now used in the kernel. This means that on entry, the old value of %gs is saved away, and it is reloaded with __KERNEL_PDA. 2: entry.S constructs the stack in the shape of struct pt_regs, and this is passed around the kernel so that the process's saved register state can be accessed. Unfortunately struct pt_regs doesn't currently have space for %gs (or %fs). This patch extends pt_regs to add space for gs (no space is allocated for %fs, since it won't be used, and it would just complicate the code in entry.S to work around the space). 3: Because %gs is now saved on the stack like %ds, %es and the integer registers, there are a number of places where it no longer needs to be handled specially; namely context switch, and saving/restoring the register state in a signal context. 4: And since kernel threads run in kernel space and call normal kernel code, they need to be created with their %gs == __KERNEL_PDA. Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Andi Kleen <ak@suse.de> Cc: Chuck Ebbert <76306.1226@compuserve.com> Cc: Zachary Amsden <zach@vmware.com> Cc: Jan Beulich <jbeulich@novell.com> Cc: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org>
* [PATCH] i386: add sleazy FPU optimizationChuck Ebbert2006-12-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | i386 port of the sLeAZY-fpu feature. Chuck reports that this gives him a +/- 0.4% improvement on his simple benchmark x86_64 description follows: Right now the kernel on x86-64 has a 100% lazy fpu behavior: after *every* context switch a trap is taken for the first FPU use to restore the FPU context lazily. This is of course great for applications that have very sporadic or no FPU use (since then you avoid doing the expensive save/restore all the time). However for very frequent FPU users... you take an extra trap every context switch. The patch below adds a simple heuristic to this code: After 5 consecutive context switches of FPU use, the lazy behavior is disabled and the context gets restored every context switch. If the app indeed uses the FPU, the trap is avoided. (the chance of the 6th time slice using FPU after the previous 5 having done so are quite high obviously). After 256 switches, this is reset and lazy behavior is returned (until there are 5 consecutive ones again). The reason for this is to give apps that do longer bursts of FPU use still the lazy behavior back after some time. Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Andi Kleen <ak@suse.de>
* [PATCH] i386/x86_64: ACPI cpu_idle_wait() fixIngo Molnar2006-11-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The scheduler on Andreas Friedrich's hyperthreading system stopped working properly: the scheduler would never move tasks to another CPU! The lask known working kernel was 2.6.8. After a couple of attempts to corner the bug, the following smoking gun was found: BIOS reported wrong ACPI idfor the processor CPU#1: set_cpus_allowed(), swapper:1, 3 -> 2 [<c0103bbe>] show_trace_log_lvl+0x34/0x4a [<c0103ceb>] show_trace+0x2c/0x2e [<c01045f8>] dump_stack+0x2b/0x2d [<c0116a77>] set_cpus_allowed+0x52/0xec [<c0101d86>] cpu_idle_wait+0x2e/0x100 [<c0259c57>] acpi_processor_power_exit+0x45/0x58 [<c0259752>] acpi_processor_remove+0x46/0xea [<c025c6fb>] acpi_start_single_object+0x47/0x54 [<c025cee5>] acpi_bus_register_driver+0xa4/0xd3 [<c04ab2d7>] acpi_processor_init+0x57/0x77 [<c01004d7>] init+0x146/0x2fd [<c0103a87>] kernel_thread_helper+0x7/0x10 a quick look at cpu_idle_wait() shows how broken that code is on i386: it changes the init task's affinity map but never restores it ... and because all userspace tasks get forked by init, they all inherited that single-CPU affinity mask. x86_64 cloned this bug too. Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: Andreas Friedrich <andreas.friedrich@fujitsu-siemens.com> Cc: Wolfgang Erig <Wolfgang.Erig@fujitsu-siemens.com> Cc: Andrew Morton <akpm@osdl.org> Cc: Adrian Bunk <bunk@stusta.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] x86: Revert new unwind kernel stack terminationAndi Kleen2006-10-21
| | | | | | | | | Jan convinced me that it was unnecessary because the assembly stubs do this already on the stack. Cc: jbeulich@novell.com Signed-off-by: Andi Kleen <ak@suse.de>
* ACPI: Processor native C-states using MWAITVenkatesh Pallipadi2006-10-14
| | | | | | | | | | | | | | | | | | | | | | | | | Intel processors starting with the Core Duo support support processor native C-state using the MWAIT instruction. Refer: Intel Architecture Software Developer's Manual http://www.intel.com/design/Pentium4/manuals/253668.htm Platform firmware exports the support for Native C-state to OS using ACPI _PDC and _CST methods. Refer: Intel Processor Vendor-Specific ACPI: Interface Specification http://www.intel.com/technology/iapc/acpi/downloads/302223.htm With Processor Native C-state, we use 'MWAIT' instruction on the processor to enter different C-states (C1, C2, C3). We won't use the special IO ports to enter C-state and no SMM mode etc required to enter C-state. Overall this will mean better C-state support. One major advantage of using MWAIT for all C-states is, with this and "treat interrupt as break event" feature of MWAIT, we can now get accurate timing for the time spent in C1, C2, .. states. Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Len Brown <len.brown@intel.com>
* [PATCH] x86: Terminate the kernel stacks for the unwinderAndi Kleen2006-10-05
| | | | | | | | | | | | Always make sure RIP/EIP is 0 in the registers stored on the top of the stack of a kernel thread. This makes sure the unwinder code won't try a fallback but knows the stack has ended. AK: this patch is a bit mysterious. in theory they should be terminated anyways, but it seems to fix at least one crash. Anyways double termination probably doesn't hurt. Signed-off-by: Andi Kleen <ak@suse.de>
* [PATCH] namespaces: utsname: use init_utsname when appropriateSerge E. Hallyn2006-10-02
| | | | | | | | | | | | | | | | | | | | | In some places, particularly drivers and __init code, the init utsns is the appropriate one to use. This patch replaces those with a the init_utsname helper. Changes: Removed several uses of init_utsname(). Hope I picked all the right ones in net/ipv4/ipconfig.c. These are now changed to utsname() (the per-process namespace utsname) in the previous patch (2/7) [akpm@osdl.org: CIFS fix] Signed-off-by: Serge E. Hallyn <serue@us.ibm.com> Cc: Kirill Korotaev <dev@openvz.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Herbert Poetzl <herbert@13thfloor.at> Cc: Andrey Savochkin <saw@sw.ru> Cc: Serge Hallyn <serue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] kmemdup: some usersAlexey Dobriyan2006-10-01
| | | | | Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] i386: Allow a kernel not to be in ring 0Rusty Russell2006-09-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We allow for the fact that the guest kernel may not run in ring 0. This requires some abstraction in a few places when setting %cs or checking privilege level (user vs kernel). This is Chris' [RFC PATCH 15/33] move segment checks to subarch, except rather than using #define USER_MODE_MASK which depends on a config option, we use Zach's more flexible approach of assuming ring 3 == userspace. I also used "get_kernel_rpl()" over "get_kernel_cs()" because I think it reads better in the code... 1) Remove the hardcoded 3 and introduce #define SEGMENT_RPL_MASK 3 2) Add a get_kernel_rpl() macro, and don't assume it's zero. And: Clean up of patch for letting kernel run other than ring 0: a. Add some comments about the SEGMENT_IS_*_CODE() macros. b. Add a USER_RPL macro. (Code was comparing a value to a mask in some places and to the magic number 3 in other places.) c. Add macros for table indicator field and use them. d. Change the entry.S tests for LDT stack segment to use the macros Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Zachary Amsden <zach@vmware.com> Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Andi Kleen <ak@suse.de>
* [PATCH] i386: move kernel_thread_helper into entry.SAndi Kleen2006-09-26
| | | | | | | | | | | And add proper CFI annotation to it which was previously impossible. This prevents "stuck" messages by the dwarf2 unwinder when reaching the top of a kernel stack. Includes feedback from Jan Beulich Cc: jbeulich@novell.com Signed-off-by: Andi Kleen <ak@suse.de>
* [PATCH] i386/x86-64: Don't randomize stack top when no randomization ↵Andi Kleen2006-09-26
| | | | | | | | | personality is set Based on patch from Frank van Maarseveen <frankvm@frankvm.com>, but extended. Signed-off-by: Andi Kleen <ak@suse.de>
* [PATCH] i386: switch_to(): misplaced parenthesesChuck Ebbert2006-07-28
| | | | | | | | | Recent changes in i386 __switch_to() have a misplaced closing parenthesis causing an unlikely() to terminate early. Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] i386: use thread_info flags for debug regs and IO bitmapsStephane Eranian2006-07-09
| | | | | | | | | | | | | | | | | | | | Use thread info flags to track use of debug registers and IO bitmaps. - add TIF_DEBUG to track when debug registers are active - add TIF_IO_BITMAP to track when I/O bitmap is used - modify __switch_to() to use the new TIF flags Performance tested on Pentium II, ten runs of LMbench context switch benchmark (smaller is better:) before after avg 3.65 3.39 min 3.55 3.33 Signed-off-by: Stephane Eranian <eranian@hpl.hp.com> Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com> Acked-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* Remove obsolete #include <linux/config.h>Jörn Engel2006-06-30
| | | | | Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
* [PATCH] i386/x86-64/ia64: Move polling flag into thread_info_statusAndi Kleen2006-06-26
| | | | | | | | | | | | | | | | | | During some profiling I noticed that default_idle causes a lot of memory traffic. I think that is caused by the atomic operations to clear/set the polling flag in thread_info. There is actually no reason to make this atomic - only the idle thread does it to itself, other CPUs only read it. So I moved it into ti->status. Converted i386/x86-64/ia64 for now because that was the easiest way to fix ACPI which also manipulates these flags in its idle function. Cc: Nick Piggin <npiggin@novell.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Len Brown <len.brown@intel.com> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] i386: reliable stack trace support (i386)Jan Beulich2006-06-26
| | | | | | | | | | These are the i386-specific pieces to enable reliable stack traces. This is going to be even more useful once CFI annotations get added to he assembly code, namely to entry.S. Signed-off-by: Jan Beulich <jbeulich@novell.com> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] unexport get_wchanAdrian Bunk2006-03-31
| | | | | | | | The only user of get_wchan is the proc fs - and proc can't be built modular. Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] kretprobe instance recycled by parent processbibo mao2006-03-26
| | | | | | | | | | | | | | | | | When kretprobe probes the schedule() function, if the probed process exits then schedule() will never return, so some kretprobe instances will never be recycled. In this patch the parent process will recycle retprobe instances of the probed function and there will be no memory leak of kretprobe instances. Signed-off-by: bibo mao <bibo.mao@intel.com> Cc: Masami Hiramatsu <hiramatu@sdl.hitachi.co.jp> Cc: Prasanna S Panchamukhi <prasanna@in.ibm.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] i386: fix uses of user_mode() vs. user_mode_vm()Jan Beulich2006-03-23
| | | | | | | | | | | | | | | | | | | | | | | >commit 76381fee7e8feb4c22be636aa5d4765dbe4fbf9e >Author: Vincent Hanquez <vincent.hanquez@cl.cam.ac.uk> >Date: Thu Jun 23 00:08:46 2005 -0700 > > [PATCH] xen: x86_64: use more usermode macro > > Make use of the user_mode macro where it's possible. This is useful for Xen > because it will need only to redefine only the macro to a hypervisor call. I am of the opinion that the above changeset is incomplete, i.e. it missed converting some previous uses of user_mode to user_mode_vm. While most of them could be considered just cosmetical, at least the one in die_nmi doesn't appear to be. Signed-off-by: Jan Beulich <jbeulich@novell.com> Cc: Vincent Hanquez <vincent.hanquez@cl.cam.ac.uk> Cc: Zachary Amsden <zach@vmware.com> Cc: James Bottomley <James.Bottomley@steeleye.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] i386: print kernel version in register dumpsChuck Ebbert2006-02-05
| | | | | | | | | | | | | Show first field of kernel version in register dumps like x86_64 does. Changes output from e.g.: (2.6.16-rc1) to: (2.6.16-rc1 #12) Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] i386: task_stack_page()Al Viro2006-01-12
| | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] i386: fix task_pt_regs()akpm@osdl.org2006-01-12
| | | | | | | | | | | | ) From: Al Viro <viro@ftp.linux.org.uk> task_pt_regs() needs the same offset-by-8 to match copy_thread() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] i386: task_thread_info()Al Viro2006-01-12
| | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Make vm86 support optionalMatt Mackall2006-01-08
| | | | | | | | | | | | | | | | | | | This adds an option to remove vm86 support under CONFIG_EMBEDDED. Saves about 5k. This version eliminates most of the #ifdefs of the previous version and instead uses function stubs in vm86.h. Also, release_vm86_irqs is moved from asm-i386/irq.h to a more appropriate home in vm86.h so that the stubs can live together. $ size vmlinux-baseline vmlinux-novm86 text data bss dec hex filename 2920821 523232 190652 3634705 377611 vmlinux-baseline 2916268 523100 190492 3629860 376324 vmlinux-novm86 Signed-off-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] x86: Deprecate useless bugZachary Amsden2006-01-06
| | | | | | | | | | | | Remove the "temporary debugging check" which has managed to live for quite some time, and is clearly unneeded. The mm can never be live at this point, so clearly checking the LDT in the mm->context is redundant as well. Signed-off-by: Zachary Amsden <zach@vmware.com> Cc: "Seth, Rohit" <rohit.seth@intel.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] x86: Cr4 is valid on some 486sZachary Amsden2006-01-06
| | | | | | | | | | | | | | So some 486 processors do have CR4 register. Allow them to present it in register dumps by using the old fault technique rather than testing processor family. Thanks to Maciej for noticing this. Signed-off-by: Zachary Amsden <zach@vmware.com> Cc: "Seth, Rohit" <rohit.seth@intel.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] x86: teach dump_task_regs() about the -8 offset.Stas Sergeev2005-12-31
| | | | | | | This should fix multi-threaded core-files Signed-off-by: stsp@aknet.ru Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] kprobes: Fix return probes on sys_execveJim Keniston2005-11-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix a bug in kprobes that can cause an Oops or even a crash when a return probe is installed on one of the following functions: sys_execve, do_execve, load_*_binary, flush_old_exec, or flush_thread. The fix is to remove the call to kprobe_flush_task() in flush_thread(). This fix has been tested on all architectures for which the return-probes feature has been implemented (i386, x86_64, ppc64, ia64). Please apply. BACKGROUND Up to now, we have called kprobe_flush_task() under two situations: when a task exits, and when it execs. Flushing kretprobe_instances on exit is correct because (a) do_exit() doesn't return, and (b) one or more return-probed functions may be active when a task calls do_exit(). Neither is the case for sys_execve() and its callees. Initially, the mistaken call to kprobe_flush_task() on exec was harmless because we put the "real" return address of each active probed function back in the stack, just to be safe, when we recycled its kretprobe_instance. When support for ppc64 and ia64 was added, this safety measure couldn't be employed, and was eventually dropped even for i386 and x86_64. sys_execve() and its callees were informally blacklisted for return probes until this fix was developed. Acked-by: Prasanna S Panchamukhi <prasanna@in.ibm.com> Signed-off-by: Jim Keniston <jkenisto@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] sched: resched and cpu_idle reworkNick Piggin2005-11-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make some changes to the NEED_RESCHED and POLLING_NRFLAG to reduce confusion, and make their semantics rigid. Improves efficiency of resched_task and some cpu_idle routines. * In resched_task: - TIF_NEED_RESCHED is only cleared with the task's runqueue lock held, and as we hold it during resched_task, then there is no need for an atomic test and set there. The only other time this should be set is when the task's quantum expires, in the timer interrupt - this is protected against because the rq lock is irq-safe. - If TIF_NEED_RESCHED is set, then we don't need to do anything. It won't get unset until the task get's schedule()d off. - If we are running on the same CPU as the task we resched, then set TIF_NEED_RESCHED and no further action is required. - If we are running on another CPU, and TIF_POLLING_NRFLAG is *not* set after TIF_NEED_RESCHED has been set, then we need to send an IPI. Using these rules, we are able to remove the test and set operation in resched_task, and make clear the previously vague semantics of POLLING_NRFLAG. * In idle routines: - Enter cpu_idle with preempt disabled. When the need_resched() condition becomes true, explicitly call schedule(). This makes things a bit clearer (IMO), but haven't updated all architectures yet. - Many do a test and clear of TIF_NEED_RESCHED for some reason. According to the resched_task rules, this isn't needed (and actually breaks the assumption that TIF_NEED_RESCHED is only cleared with the runqueue lock held). So remove that. Generally one less locked memory op when switching to the idle thread. - Many idle routines clear TIF_POLLING_NRFLAG, and only set it in the inner most polling idle loops. The above resched_task semantics allow it to be set until before the last time need_resched() is checked before going into a halt requiring interrupt wakeup. Many idle routines simply never enter such a halt, and so POLLING_NRFLAG can be always left set, completely eliminating resched IPIs when rescheduling the idle task. POLLING_NRFLAG width can be increased, to reduce the chance of resched IPIs. Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: Con Kolivas <kernel@kolivas.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] sched: disable preempt in idle tasksNick Piggin2005-11-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Run idle threads with preempt disabled. Also corrected a bugs in arm26's cpu_idle (make it actually call schedule()). How did it ever work before? Might fix the CPU hotplugging hang which Nigel Cunningham noted. We think the bug hits if the idle thread is preempted after checking need_resched() and before going to sleep, then the CPU offlined. After calling stop_machine_run, the CPU eventually returns from preemption and into the idle thread and goes to sleep. The CPU will continue executing previous idle and have no chance to call play_dead. By disabling preemption until we are ready to explicitly schedule, this bug is fixed and the idle threads generally become more robust. From: alexs <ashepard@u.washington.edu> PPC build fix From: Yoichi Yuasa <yuasa@hh.iij4u.or.jp> MIPS build fix Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Yoichi Yuasa <yuasa@hh.iij4u.or.jp> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] useless includes of linux/irq.h in arch/i386Al Viro2005-09-26
| | | | | | | | | | Most of these guys are simply not needed (pulled by other stuff via asm-i386/hardirq.h). One that is not entirely useless is hilarious - arch/i386/oprofile/nmi_timer_int.c includes linux/irq.h... as a way to get linux/errno.h Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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