kernel.git/include/asm-i386/processor.h, branch linux-2.6.21.y

Revert "[PATCH] i386: add idle notifier"

2007-02-26T17:21:46Z

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 Cc: Andi Kleen Cc: Andrew Morton Cc: Uwe Bugla Cc: Jiri Slaby Signed-off-by: Linus Torvalds

[PATCH] i386: add idle notifier

2007-02-13T12:26:22Z

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 Signed-off-by: Andrew Morton Signed-off-by: Andi Kleen

[PATCH] i386: Convert i386 PDA code to use %fs

2007-02-13T12:26:20Z

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 Signed-off-by: Andi Kleen Cc: Ian Campbell Acked-by: Ingo Molnar Acked-by: Zachary Amsden Cc: Eric Dumazet Signed-off-by: Frederik Deweerdt Signed-off-by: Andrew Morton

[PATCH] x86: fix PDA variables to work during boot

2007-01-23T03:39:36Z

The current PDA code, which went in in post 2.6.19 has a flaw in that it doesn't correctly cycle the GDT and %GS segment through the boot PDA, the CPU PDA and finally the per-cpu PDA. The bug generally doesn't show up if the boot CPU id is zero, but everything falls apart for a non zero boot CPU id. The basically kills voyager which is perfectly capable of doing non zero CPU id boots, so voyager currently won't boot without this. The fix is to be careful and actually do the GDT setups correctly. Signed-off-by: James Bottomley Cc: Andi Kleen Cc: Jeremy Fitzhardinge Cc: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] i386: cpu_detect extraction

2006-12-07T01:14:08Z

Both lhype and Xen want to call the core of the x86 cpu detect code before calling start_kernel. (extracted from larger patch) AK: folded in start_kernel header patch Signed-off-by: Jeremy Fitzhardinge Signed-off-by: Rusty Russell Signed-off-by: Andi Kleen Cc: Jeremy Fitzhardinge Cc: Andi Kleen Signed-off-by: Andrew Morton

[PATCH] paravirt: Patch inline replacements for paravirt intercepts

2006-12-07T01:14:08Z

It turns out that the most called ops, by several orders of magnitude, are the interrupt manipulation ops. These are obvious candidates for patching, so mark them up and create infrastructure for it. The method used is that the ops structure has a patch function, which is called for each place which needs to be patched: this returns a number of instructions (the rest are NOP-padded). Usually we can spare a register (%eax) for the binary patched code to use, but in a couple of critical places in entry.S we can't: we make the clobbers explicit at the call site, and manually clobber the allowed registers in debug mode as an extra check. And: Don't abuse CONFIG_DEBUG_KERNEL, add CONFIG_DEBUG_PARAVIRT. And: AK: Fix warnings in x86-64 alternative.c build And: AK: Fix compilation with defconfig And: ^From: Andrew Morton Some binutlises still like to emit references to __stop_parainstructions and __start_parainstructions. And: AK: Fix warnings about unused variables when PARAVIRT is disabled. Signed-off-by: Rusty Russell Signed-off-by: Jeremy Fitzhardinge Signed-off-by: Chris Wright Signed-off-by: Zachary Amsden Signed-off-by: Andi Kleen Signed-off-by: Andrew Morton

[PATCH] paravirt: header and stubs for paravirtualisation

2006-12-07T01:14:07Z

Create a paravirt.h header for all the critical operations which need to be replaced with hypervisor calls, and include that instead of defining native operations, when CONFIG_PARAVIRT. This patch does the dumbest possible replacement of paravirtualized instructions: calls through a "paravirt_ops" structure. Currently these are function implementations of native hardware: hypervisors will override the ops structure with their own variants. All the pv-ops functions are declared "fastcall" so that a specific register-based ABI is used, to make inlining assember easier. And: +From: Andy Whitcroft The paravirt ops introduce a 'weak' attribute onto memory_setup(). Code ordering leads to the following warnings on x86: arch/i386/kernel/setup.c:651: warning: weak declaration of `memory_setup' after first use results in unspecified behavior Move memory_setup() to avoid this. Signed-off-by: Rusty Russell Signed-off-by: Chris Wright Signed-off-by: Andi Kleen Cc: Jeremy Fitzhardinge Cc: Zachary Amsden Signed-off-by: Andrew Morton Signed-off-by: Andy Whitcroft

[PATCH] i386: Retrieve CLFLUSH size from CPUID

2006-12-07T01:14:05Z

Also report it in /proc/cpuinfo similar to x86-64. Needed for followon patch Signed-off-by: Andi Kleen

[PATCH] i386: Use %gs as the PDA base-segment in the kernel

2006-12-07T01:14:02Z

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 Signed-off-by: Andi Kleen Cc: Chuck Ebbert <76306.1226@compuserve.com> Cc: Zachary Amsden Cc: Jan Beulich Cc: Andi Kleen Signed-off-by: Andrew Morton

[PATCH] i386: Initialize the per-CPU data area

2006-12-07T01:14:02Z

When a CPU is brought up, a PDA and GDT are allocated for it. The GDT's __KERNEL_PDA entry is pointed to the allocated PDA memory, so that all references using this segment descriptor will refer to the PDA. This patch rearranges CPU initialization a bit, so that the GDT/PDA are set up as early as possible in cpu_init(). Also for secondary CPUs, GDT+PDA are preallocated and initialized so all the secondary CPU needs to do is set up the ldt and load %gs. This will be important once smp_processor_id() and current use the PDA. In all cases, the PDA is set up in head.S, before a CPU starts running C code, so the PDA is always available. Signed-off-by: Jeremy Fitzhardinge Signed-off-by: Andi Kleen Cc: Chuck Ebbert <76306.1226@compuserve.com> Cc: Zachary Amsden Cc: Jan Beulich Cc: Andi Kleen Cc: James Bottomley Cc: Matt Tolentino Signed-off-by: Andrew Morton