lkml.org 
[lkml]   [2009]   [Apr]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 0/2] [GIT PULL] tracing: various bug fixes
* Chris Wright (chrisw@sous-sol.org) wrote:
> * Jeremy Fitzhardinge (jeremy@goop.org) wrote:
> > OK, the good news is that its not a callee-save calling convention
> > problem, which is what I feared. But it does sound pretty awkward to
> > fix. Does __native_flush_tlb_global() have to use
> > raw_local_irq_save/restore?
>
> Vaguely related...makes sense to do native_(read/write)_cr4 since it's
> the native tlb flushing implementation, no?
>
> looks ok from inspection, not tested yet...

BTW, Steve, does that fix it for you? Sure makes the code cleaner:

410: 0f 20 e2 mov %cr4,%rdx
413: 48 89 d0 mov %rdx,%rax
416: 24 7f and $0x7f,%al
418: 0f 22 e0 mov %rax,%cr4
41b: 0f 22 e2 mov %rdx,%cr4

thanks,
-chris

> Subject: [PATCH] x86: use native register access for native tlb flushing
>
> currently these are paravirtulaized, doesn't appear any callers rely on
> this (no pv_ops backends are using native_tlb and overriding cr3/4
> access).
>
> Signed-off-by: Chris Wright <chrisw@sous-sol.org>
> ---
> arch/x86/include/asm/tlbflush.h | 8 ++++----
> 1 files changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/arch/x86/include/asm/tlbflush.h b/arch/x86/include/asm/tlbflush.h
> index 16a5c84..a5ecc9c 100644
> --- a/arch/x86/include/asm/tlbflush.h
> +++ b/arch/x86/include/asm/tlbflush.h
> @@ -17,7 +17,7 @@
>
> static inline void __native_flush_tlb(void)
> {
> - write_cr3(read_cr3());
> + native_write_cr3(native_read_cr3());
> }
>
> static inline void __native_flush_tlb_global(void)
> @@ -32,11 +32,11 @@ static inline void __native_flush_tlb_global(void)
> */
> raw_local_irq_save(flags);
>
> - cr4 = read_cr4();
> + cr4 = native_read_cr4();
> /* clear PGE */
> - write_cr4(cr4 & ~X86_CR4_PGE);
> + native_write_cr4(cr4 & ~X86_CR4_PGE);
> /* write old PGE again and flush TLBs */
> - write_cr4(cr4);
> + native_write_cr4(cr4);
>
> raw_local_irq_restore(flags);
> }


\
 
 \ /
  Last update: 2009-04-23 20:07    [from the cache]
©2003-2011 Jasper Spaans