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2007-02-26Revert "[PATCH] i386: add idle notifier"Linus Torvalds
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>
2007-02-13[PATCH] i386: Small cleanup to TLB flush codeAndi Kleen
- Remove outdated comment - Use cpu_relax() in a busy loop Signed-off-by: Andi Kleen <ak@suse.de>
2007-02-13[PATCH] i386: add idle notifierStephane Eranian
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>
2006-12-07Merge branch 'for-linus' of git://one.firstfloor.org/home/andi/git/linux-2.6Linus Torvalds
* 'for-linus' of git://one.firstfloor.org/home/andi/git/linux-2.6: (156 commits) [PATCH] x86-64: Export smp_call_function_single [PATCH] i386: Clean up smp_tune_scheduling() [PATCH] unwinder: move .eh_frame to RODATA [PATCH] unwinder: fully support linker generated .eh_frame_hdr section [PATCH] x86-64: don't use set_irq_regs() [PATCH] x86-64: check vector in setup_ioapic_dest to verify if need setup_IO_APIC_irq [PATCH] x86-64: Make ix86 default to HIGHMEM4G instead of NOHIGHMEM [PATCH] i386: replace kmalloc+memset with kzalloc [PATCH] x86-64: remove remaining pc98 code [PATCH] x86-64: remove unused variable [PATCH] x86-64: Fix constraints in atomic_add_return() [PATCH] x86-64: fix asm constraints in i386 atomic_add_return [PATCH] x86-64: Correct documentation for bzImage protocol v2.05 [PATCH] x86-64: replace kmalloc+memset with kzalloc in MTRR code [PATCH] x86-64: Fix numaq build error [PATCH] x86-64: include/asm-x86_64/cpufeature.h isn't a userspace header [PATCH] unwinder: Add debugging output to the Dwarf2 unwinder [PATCH] x86-64: Clarify error message in GART code [PATCH] x86-64: Fix interrupt race in idle callback (3rd try) [PATCH] x86-64: Remove unwind stack pointer alignment forcing again ... Fixed conflict in include/linux/uaccess.h manually Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07[PATCH] smp_call_function_single() check that local interrupts are enabledAndrew Morton
smp_call_function_single() can deadlock if the caller disabled local interrupts (the target CPU could be spinning on call_lock). Check for that. Why on earth do these functions use spin_lock_bh()?? Cc: "Randy.Dunlap" <rdunlap@xenotime.net> Cc: Andi Kleen <ak@suse.de> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07[PATCH] x86-64: don't use set_irq_regs()Oleg Nesterov
We don't need to setup _irq_regs in smp_xxx_interrupt (except apic timer). These handlers run with irqs disabled and do not call functions which need "struct pt_regs". Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andi Kleen <ak@suse.de> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Andi Kleen <ak@suse.de> Acked-By: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org>
2006-10-05IRQ: Maintain regs pointer globally rather than passing to IRQ handlersDavid Howells
Maintain a per-CPU global "struct pt_regs *" variable which can be used instead of passing regs around manually through all ~1800 interrupt handlers in the Linux kernel. The regs pointer is used in few places, but it potentially costs both stack space and code to pass it around. On the FRV arch, removing the regs parameter from all the genirq function results in a 20% speed up of the IRQ exit path (ie: from leaving timer_interrupt() to leaving do_IRQ()). Where appropriate, an arch may override the generic storage facility and do something different with the variable. On FRV, for instance, the address is maintained in GR28 at all times inside the kernel as part of general exception handling. Having looked over the code, it appears that the parameter may be handed down through up to twenty or so layers of functions. Consider a USB character device attached to a USB hub, attached to a USB controller that posts its interrupts through a cascaded auxiliary interrupt controller. A character device driver may want to pass regs to the sysrq handler through the input layer which adds another few layers of parameter passing. I've build this code with allyesconfig for x86_64 and i386. I've runtested the main part of the code on FRV and i386, though I can't test most of the drivers. I've also done partial conversion for powerpc and MIPS - these at least compile with minimal configurations. This will affect all archs. Mostly the changes should be relatively easy. Take do_IRQ(), store the regs pointer at the beginning, saving the old one: struct pt_regs *old_regs = set_irq_regs(regs); And put the old one back at the end: set_irq_regs(old_regs); Don't pass regs through to generic_handle_irq() or __do_IRQ(). In timer_interrupt(), this sort of change will be necessary: - update_process_times(user_mode(regs)); - profile_tick(CPU_PROFILING, regs); + update_process_times(user_mode(get_irq_regs())); + profile_tick(CPU_PROFILING); I'd like to move update_process_times()'s use of get_irq_regs() into itself, except that i386, alone of the archs, uses something other than user_mode(). Some notes on the interrupt handling in the drivers: (*) input_dev() is now gone entirely. The regs pointer is no longer stored in the input_dev struct. (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking. It does something different depending on whether it's been supplied with a regs pointer or not. (*) Various IRQ handler function pointers have been moved to type irq_handler_t. Signed-Off-By: David Howells <dhowells@redhat.com> (cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
2006-10-01[PATCH] stack overflow safe kdump: safe_smp_processor_id()Fernando Vazquez
This is a the first of a series of patch-sets aiming at making kdump more robust against stack overflows. This patch set does the following: * Add safe_smp_processor_id function to i386 architecture (this function was inspired by the x86_64 function of the same name). * Substitute "smp_processor_id" with the stack overflow-safe "safe_smp_processor_id" in the reboot path to the second kernel. This patch: On the event of a stack overflow critical data that usually resides at the bottom of the stack is likely to be stomped and, consequently, its use should be avoided. In particular, in the i386 and IA64 architectures the macro smp_processor_id ultimately makes use of the "cpu" member of struct thread_info which resides at the bottom of the stack. x86_64, on the other hand, is not affected by this problem because it benefits from the use of the PDA infrastructure. To circumvent this problem I suggest implementing "safe_smp_processor_id()" (it already exists in x86_64) for i386 and IA64 and use it as a replacement for smp_processor_id in the reboot path to the dump capture kernel. This is a possible implementation for i386. Signed-off-by: Fernando Vazquez <fernando@intellilink.co.jp> Looks-reasonable-to: Andi Kleen <ak@muc.de> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Vivek Goyal <vgoyal@in.ibm.com> Cc: James Bottomley <James.Bottomley@steeleye.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-26[PATCH] smp_call_function_single() cleanupAndrew Morton
If we're going to implement smp_call_function_single() on three architecture with the same prototype then it should have a declaration in a non-arch-specific header file. Move it into <linux/smp.h>. Cc: Stephane Eranian <eranian@hpl.hp.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-26[PATCH] i386: add smp_call_function_singleStephane Eranian
Continiung the series of small patches necessary for the perfmon subsystem, here is a patch that adds support for the smp_call_function_single() function for i386. It exists for almost all other architectures but i386. The perfmon subsystem needs it in one case to free some state on a designated remote CPU. Signed-off-by: Stephane Eranian <eranian@hpl.hp.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26[PATCH] x86_64: Standardize i386/x86_64 handling of NMI_VECTORKeith Owens
x86_64 and i386 behave inconsistently when sending an IPI on vector 2 (NMI_VECTOR). Make both behave the same, so IPI 2 is sent as NMI. The crash code was abusing send_IPI_allbutself() by passing a code instead of a vector, it only worked because crash knew about the internal code of send_IPI_allbutself(). Change crash to use NMI_VECTOR instead, and remove the comment about how crash was abusing the function. This patch is a pre-requisite for fixing the problem where sending an IPI as NMI would reboot some Dell Xeon systems. I cannot fix that problem while crash continus to abuse send_IPI_allbutself(). It also removes the inconsistency between i386 and x86_64 for NMI_VECTOR. That will simplify all the RAS code that needs to bring all the cpus to a clean stop, even when one or more cpus are spinning disabled. Signed-off-by: Keith Owens <kaos@sgi.com> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-22[PATCH] on_each_cpu(): disable local interruptsAndrew Morton
When on_each_cpu() runs the callback on other CPUs, it runs with local interrupts disabled. So we should run the function with local interrupts disabled on this CPU, too. And do the same for UP, so the callback is run in the same environment on both UP and SMP. (strictly it should do preempt_disable() too, but I think local_irq_disable is sufficiently equivalent). Also uninlines on_each_cpu(). softirq.c was the most appropriate file I could find, but it doesn't seem to justify creating a new file. Oh, and fix up that comment over (under?) x86's smp_call_function(). It drives me nuts. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-26[PATCH] useless includes of linux/irq.h in arch/i386Al Viro
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>
2005-09-05[PATCH] i386: inline asm cleanupZachary Amsden
i386 Inline asm cleanup. Use cr/dr accessor functions. Also, a potential bugfix. Also, some CR accessors really should be volatile. Reads from CR0 (numeric state may change in an exception handler), writes to CR4 (flipping CR4.TSD) and reads from CR2 (page fault) prevent instruction re-ordering. I did not add memory clobber to CR3 / CR4 / CR0 updates, as it was not there to begin with, and in no case should kernel memory be clobbered, except when doing a TLB flush, which already has memory clobber. I noticed that page invalidation does not have a memory clobber. I can't find a bug as a result, but there is definitely a potential for a bug here: #define __flush_tlb_single(addr) \ __asm__ __volatile__("invlpg %0": :"m" (*(char *) addr)) Signed-off-by: Zachary Amsden <zach@vmware.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25[PATCH] sep initializing reworkLi Shaohua
Make SEP init per-cpu, so it is hotplug safe. Signed-off-by: Li Shaohua<shaohua.li@intel.com> Signed-off-by: Ashok Raj <ashok.raj@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25[PATCH] i386 CPU hotplugZwane Mwaikambo
(The i386 CPU hotplug patch provides infrastructure for some work which Pavel is doing as well as for ACPI S3 (suspend-to-RAM) work which Li Shaohua <shaohua.li@intel.com> is doing) The following provides i386 architecture support for safely unregistering and registering processors during runtime, updated for the current -mm tree. In order to avoid dumping cpu hotplug code into kernel/irq/* i dropped the cpu_online check in do_IRQ() by modifying fixup_irqs(). The difference being that on cpu offline, fixup_irqs() is called before we clear the cpu from cpu_online_map and a long delay in order to ensure that we never have any queued external interrupts on the APICs. There are additional changes to s390 and ppc64 to account for this change. 1) Add CONFIG_HOTPLUG_CPU 2) disable local APIC timer on dead cpus. 3) Disable preempt around irq balancing to prevent CPUs going down. 4) Print irq stats for all possible cpus. 5) Debugging check for interrupts on offline cpus. 6) Hacky fixup_irqs() to redirect irqs when cpus go off/online. 7) play_dead() for offline cpus to spin inside. 8) Handle offline cpus set in flush_tlb_others(). 9) Grab lock earlier in smp_call_function() to prevent CPUs going down. 10) Implement __cpu_disable() and __cpu_die(). 11) Enable local interrupts in cpu_enable() after fixup_irqs() 12) Don't fiddle with NMI on dead cpu, but leave intact on other cpus. 13) Program IRQ affinity whilst cpu is still in cpu_online_map on offline. Signed-off-by: Zwane Mwaikambo <zwane@linuxpower.ca> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-23[PATCH] Remove i386_ksyms.c, almost.Alexey Dobriyan
* EXPORT_SYMBOL's moved to other files * #include <linux/config.h>, <linux/module.h> where needed * #include's in i386_ksyms.c cleaned up * After copy-paste, redundant due to Makefiles rules preprocessor directives removed: #ifdef CONFIG_FOO EXPORT_SYMBOL(foo); #endif obj-$(CONFIG_FOO) += foo.o * Tiny reformat to fit in 80 columns Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-04-16Linux-2.6.12-rc2Linus Torvalds
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!