From 81683cc8277e79decff4d0cf82ae0e17d2fe465f Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Wed, 22 Apr 2015 11:52:13 +0200 Subject: [PATCH] x86/fpu: Factor out fpu__flush_thread() from flush_thread() flush_thread() open codes a lot of FPU internals - create a separate function for it in fpu/core.c. Turns out that this does not hurt performance: text data bss dec hex filename 11843039 1884440 1130496 14857975 e2b6f7 vmlinux.before 11843039 1884440 1130496 14857975 e2b6f7 vmlinux.after and since this is a slowpath clarity comes first anyway. We can reconsider inlining decisions after the FPU code has been cleaned up. Reviewed-by: Borislav Petkov Cc: Andy Lutomirski Cc: Dave Hansen Cc: Fenghua Yu Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Oleg Nesterov Cc: Peter Zijlstra Cc: Thomas Gleixner Signed-off-by: Ingo Molnar --- arch/x86/include/asm/i387.h | 1 + arch/x86/kernel/fpu/core.c | 17 +++++++++++++++++ arch/x86/kernel/process.c | 14 +------------- 3 files changed, 19 insertions(+), 13 deletions(-) diff --git a/arch/x86/include/asm/i387.h b/arch/x86/include/asm/i387.h index 6552a16e0e38..d6fc84440b73 100644 --- a/arch/x86/include/asm/i387.h +++ b/arch/x86/include/asm/i387.h @@ -20,6 +20,7 @@ struct user_i387_struct; extern int fpstate_alloc_init(struct task_struct *curr); extern void fpstate_init(struct fpu *fpu); +extern void fpu__flush_thread(struct task_struct *tsk); extern int dump_fpu(struct pt_regs *, struct user_i387_struct *); extern void math_state_restore(void); diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c index 9211582f5d3f..787bf57b8422 100644 --- a/arch/x86/kernel/fpu/core.c +++ b/arch/x86/kernel/fpu/core.c @@ -227,6 +227,23 @@ static int fpu__unlazy_stopped(struct task_struct *child) return 0; } +void fpu__flush_thread(struct task_struct *tsk) +{ + if (!use_eager_fpu()) { + /* FPU state will be reallocated lazily at the first use. */ + drop_fpu(tsk); + fpstate_free(&tsk->thread.fpu); + } else { + if (!tsk_used_math(tsk)) { + /* kthread execs. TODO: cleanup this horror. */ + if (WARN_ON(fpstate_alloc_init(tsk))) + force_sig(SIGKILL, tsk); + user_fpu_begin(); + } + restore_init_xstate(); + } +} + /* * The xstateregs_active() routine is the same as the fpregs_active() routine, * as the "regset->n" for the xstate regset will be updated based on the feature diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index 6ab180f40a7e..52fd8f6f44c7 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -146,19 +146,7 @@ void flush_thread(void) flush_ptrace_hw_breakpoint(tsk); memset(tsk->thread.tls_array, 0, sizeof(tsk->thread.tls_array)); - if (!use_eager_fpu()) { - /* FPU state will be reallocated lazily at the first use. */ - drop_fpu(tsk); - fpstate_free(&tsk->thread.fpu); - } else { - if (!tsk_used_math(tsk)) { - /* kthread execs. TODO: cleanup this horror. */ - if (WARN_ON(fpstate_alloc_init(tsk))) - force_sig(SIGKILL, tsk); - user_fpu_begin(); - } - restore_init_xstate(); - } + fpu__flush_thread(tsk); } static void hard_disable_TSC(void) -- 2.34.1