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| author | Rusty Russell <rusty@rustcorp.com.au> | 2009-06-13 06:27:03 +0200 |
|---|---|---|
| committer | Rusty Russell <rusty@rustcorp.com.au> | 2009-06-12 14:57:03 +0200 |
| commit | 61f4bc83fea248a3092beb7ba43daa5629615513 (patch) | |
| tree | 5ce12fc0676f93a49f743dab1c60f8e1ca991ec3 /arch/x86/kernel/asm-offsets_32.c | |
| parent | lguest: improve interrupt handling, speed up stream networking (diff) | |
| download | linux-61f4bc83fea248a3092beb7ba43daa5629615513.tar.xz linux-61f4bc83fea248a3092beb7ba43daa5629615513.zip | |
lguest: optimize by coding restore_flags and irq_enable in assembler.
The downside of the last patch which made restore_flags and irq_enable
check interrupts is that they are now too big to be patched directly
into the callsites, so the C versions are always used.
But the C versions go via PV_CALLEE_SAVE_REGS_THUNK which saves all
the registers. In fact, we don't need any registers in the fast path,
so we can do better than this if we actually code them in assembler.
The results are in the noise, but since it's about the same amount of
code, it's worth applying.
1GB Guest->Host: input(suppressed),output(suppressed)
Before:
Seconds: 0:16.53
Packets: 377268,753673
Interrupts: 22461,24297
Notifications: 1(5245),21303(732370)
Net IRQs triggered: 377023(245),42578(711095)
After:
Seconds: 0:16.48
Packets: 377289,753673
Interrupts: 22281,24465
Notifications: 1(5245),21296(732377)
Net IRQs triggered: 377060(229),42564(711109)
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Diffstat (limited to 'arch/x86/kernel/asm-offsets_32.c')
| -rw-r--r-- | arch/x86/kernel/asm-offsets_32.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/x86/kernel/asm-offsets_32.c b/arch/x86/kernel/asm-offsets_32.c index 1a830cbd7015..dfdbf6403895 100644 --- a/arch/x86/kernel/asm-offsets_32.c +++ b/arch/x86/kernel/asm-offsets_32.c @@ -126,6 +126,7 @@ void foo(void) #if defined(CONFIG_LGUEST) || defined(CONFIG_LGUEST_GUEST) || defined(CONFIG_LGUEST_MODULE) BLANK(); OFFSET(LGUEST_DATA_irq_enabled, lguest_data, irq_enabled); + OFFSET(LGUEST_DATA_irq_pending, lguest_data, irq_pending); OFFSET(LGUEST_DATA_pgdir, lguest_data, pgdir); BLANK(); |