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| author | Jeremy Fitzhardinge | 2007-05-02 19:27:16 +0200 |
|---|---|---|
| committer | Andi Kleen | 2007-05-02 19:27:16 +0200 |
| commit | 7c3576d261ce046789a7db14f43303f8120910c7 (patch) | |
| tree | ad27a8459bbcdb183fe2411aec3b840942992ad5 /arch/i386/kernel/vmi.c | |
| parent | [PATCH] i386: Page-align the GDT (diff) | |
| download | kernel-qcow2-linux-7c3576d261ce046789a7db14f43303f8120910c7.tar.gz kernel-qcow2-linux-7c3576d261ce046789a7db14f43303f8120910c7.tar.xz kernel-qcow2-linux-7c3576d261ce046789a7db14f43303f8120910c7.zip | |
[PATCH] i386: Convert PDA into the percpu section
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>
Diffstat (limited to 'arch/i386/kernel/vmi.c')
| -rw-r--r-- | arch/i386/kernel/vmi.c | 6 |
1 files changed, 1 insertions, 5 deletions
diff --git a/arch/i386/kernel/vmi.c b/arch/i386/kernel/vmi.c index ccad7ee960aa..12312988c626 100644 --- a/arch/i386/kernel/vmi.c +++ b/arch/i386/kernel/vmi.c @@ -504,8 +504,6 @@ static void vmi_pmd_clear(pmd_t *pmd) #endif #ifdef CONFIG_SMP -extern void setup_pda(void); - static void __devinit vmi_startup_ipi_hook(int phys_apicid, unsigned long start_eip, unsigned long start_esp) @@ -530,13 +528,11 @@ vmi_startup_ipi_hook(int phys_apicid, unsigned long start_eip, ap.ds = __USER_DS; ap.es = __USER_DS; - ap.fs = __KERNEL_PDA; + ap.fs = __KERNEL_PERCPU; ap.gs = 0; ap.eflags = 0; - setup_pda(); - #ifdef CONFIG_X86_PAE /* efer should match BSP efer. */ if (cpu_has_nx) { |