From: Jan Kiszka <jan.kiszka@domain.hid>
To: adeos-main <adeos-main@gna.org>
Cc: Philippe Gerum <rpm@xenomai.org>
Subject: [Adeos-main] [PATCH 1/5] x86: optimize access to __ipipe_tick_regs
Date: Sun, 30 Dec 2007 00:12:28 +0100 [thread overview]
Message-ID: <4776D45C.80207@domain.hid> (raw)
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By intention, the compiler is not able to fold succeeding accesses to
via __raw_get_cpu_var & friends into a single one. As we are in an
atomic section in __ipipe_handle_irq, let's help him with a temporary
variable, saving some text size in this hotpath.
Jan
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---
arch/x86/kernel/ipipe_32.c | 9 +++++----
arch/x86/kernel/ipipe_64.c | 13 +++++++------
2 files changed, 12 insertions(+), 10 deletions(-)
Index: linux-2.6.24-rc6-xeno/arch/x86/kernel/ipipe_32.c
===================================================================
--- linux-2.6.24-rc6-xeno.orig/arch/x86/kernel/ipipe_32.c
+++ linux-2.6.24-rc6-xeno/arch/x86/kernel/ipipe_32.c
@@ -771,10 +771,11 @@ finalize:
* information. */
if (irq == __ipipe_tick_irq) {
- __raw_get_cpu_var(__ipipe_tick_regs).eflags = regs.eflags;
- __raw_get_cpu_var(__ipipe_tick_regs).eip = regs.eip;
- __raw_get_cpu_var(__ipipe_tick_regs).xcs = regs.xcs;
- __raw_get_cpu_var(__ipipe_tick_regs).ebp = regs.ebp;
+ struct pt_regs *tick_regs = &__raw_get_cpu_var(__ipipe_tick_regs);
+ tick_regs->eflags = regs.eflags;
+ tick_regs->xcs = regs.xcs;
+ tick_regs->eip = regs.eip;
+ tick_regs->ebp = regs.ebp;
}
/*
Index: linux-2.6.24-rc6-xeno/arch/x86/kernel/ipipe_64.c
===================================================================
--- linux-2.6.24-rc6-xeno.orig/arch/x86/kernel/ipipe_64.c
+++ linux-2.6.24-rc6-xeno/arch/x86/kernel/ipipe_64.c
@@ -751,12 +751,13 @@ int __ipipe_handle_irq(struct pt_regs *r
finalize:
if (irq == __ipipe_tick_irq) {
- __raw_get_cpu_var(__ipipe_tick_regs).rip = regs->rip;
- __raw_get_cpu_var(__ipipe_tick_regs).cs = regs->cs;
- __raw_get_cpu_var(__ipipe_tick_regs).eflags = regs->eflags;
- __raw_get_cpu_var(__ipipe_tick_regs).rbp = regs->rbp;
- __raw_get_cpu_var(__ipipe_tick_regs).rsp = regs->rsp;
- __raw_get_cpu_var(__ipipe_tick_regs).ss = regs->ss;
+ struct pt_regs *tick_regs = &__raw_get_cpu_var(__ipipe_tick_regs);
+ tick_regs->ss = regs->ss;
+ tick_regs->rsp = regs->rsp;
+ tick_regs->eflags = regs->eflags;
+ tick_regs->cs = regs->cs;
+ tick_regs->rip = regs->rip;
+ tick_regs->rbp = regs->rbp;
}
/*
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next reply other threads:[~2007-12-29 23:12 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-12-29 23:12 Jan Kiszka [this message]
2007-12-30 10:31 ` [Adeos-main] [PATCH 1/5] x86: optimize access to __ipipe_tick_regs Philippe Gerum
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