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authorSuresh Siddha <suresh.b.siddha@intel.com>2008-03-10 15:28:05 -0700
committerIngo Molnar <mingo@elte.hu>2008-04-19 19:19:55 +0200
commitaa283f49276e7d840a40fb01eee6de97eaa7e012 (patch)
treeb17b134b174666e482b1a8ad486436a3d5cdb83e /arch/x86/kernel/process_64.c
parentx86, fpu: split FPU state from task struct - v5 (diff)
downloadlinux-dev-aa283f49276e7d840a40fb01eee6de97eaa7e012.tar.xz
linux-dev-aa283f49276e7d840a40fb01eee6de97eaa7e012.zip
x86, fpu: lazy allocation of FPU area - v5
Only allocate the FPU area when the application actually uses FPU, i.e., in the first lazy FPU trap. This could save memory for non-fpu using apps. for example: on my system after boot, there are around 300 processes, with only 17 using FPU. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'arch/x86/kernel/process_64.c')
-rw-r--r--arch/x86/kernel/process_64.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index b795e831afd6..891af1a1b48a 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -533,6 +533,10 @@ start_thread(struct pt_regs *regs, unsigned long new_ip, unsigned long new_sp)
regs->ss = __USER_DS;
regs->flags = 0x200;
set_fs(USER_DS);
+ /*
+ * Free the old FP and other extended state
+ */
+ free_thread_xstate(current);
}
EXPORT_SYMBOL_GPL(start_thread);