diff mbox series

[07/31] x86/process: Clone FPU in copy_thread()

Message ID	20211011223610.705049376@linutronix.de (mailing list archive)
State	New, archived
Headers	show Return-Path: <kvm-owner@kernel.org> Message-ID: <20211011223610.705049376@linutronix.de> From: Thomas Gleixner <tglx@linutronix.de> To: LKML <linux-kernel@vger.kernel.org> Cc: x86@kernel.org, "Chang S. Bae" <chang.seok.bae@intel.com>, Dave Hansen <dave.hansen@linux.intel.com>, Arjan van de Ven <arjan@linux.intel.com>, kvm@vger.kernel.org, Paolo Bonzini <pbonzini@redhat.com> Subject: [patch 07/31] x86/process: Clone FPU in copy_thread() References: <20211011215813.558681373@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Date: Tue, 12 Oct 2021 02:00:08 +0200 (CEST) Precedence: bulk
Series	x86/fpu: Preparatory cleanups for AMX support (part 1) \| expand [00/31] x86/fpu: Preparatory cleanups for AMX support (part 1) [01/31] x86/fpu: Remove pointless argument from switch_fpu_finish() [02/31] x86/fpu: Update stale comments [03/31] x86/pkru: Remove useless include [04/31] x86/fpu: Restrict xsaves()/xrstors() to independent states [05/31] x86/fpu: Cleanup the on_boot_cpu clutter [06/31] x86/fpu: Remove pointless memset in fpu_clone() [07/31] x86/process: Clone FPU in copy_thread() [08/31] x86/fpu: Do not inherit FPU context for kernel and IO worker threads [09/31] x86/fpu: Do not inherit FPU context for CLONE_THREAD [10/31] x86/fpu: Cleanup xstate xcomp_bv initialization [11/31] x86/fpu/xstate: Provide and use for_each_xfeature() [12/31] x86/fpu/xstate: Mark all init only functions __init [13/31] x86/fpu: Move KVMs FPU swapping to FPU core [14/31] x86/fpu: Replace KVMs homebrewn FPU copy from user [15/31] x86/fpu: Rework copy_xstate_to_uabi_buf() [16/31] x86/fpu: Replace KVMs homebrewn FPU copy to user [17/31] x86/fpu: Mark fpu__init_prepare_fx_sw_frame() as __init [18/31] x86/fpu: Move context switch and exit to user inlines into sched.h [19/31] x86/fpu: Clean up cpu feature tests [20/31] x86/fpu: Make os_xrstor_booting() private [21/31] x86/fpu: Move os_xsave() and os_xrstor() to core [22/31] x86/fpu: Move legacy ASM wrappers to core [23/31] x86/fpu: Make WARN_ON_FPU() private [24/31] x86/fpu: Move fpregs_restore_userregs() to core [25/31] x86/fpu: Move mxcsr related code to core [26/31] x86/fpu: Move fpstate functions to api.h [27/31] x86/fpu: Remove internal.h dependency from fpu/signal.h [28/31] x86/sev: Include fpu/xcr.h [29/31] x86/fpu: Mop up the internal.h leftovers [30/31] x86/fpu: Replace the includes of fpu/internal.h [31/31] x86/fpu: Provide a proper function for ex_handler_fprestore()

Commit Message

Thomas Gleixner Oct. 12, 2021, midnight UTC

There is no reason to clone FPU in arch_dup_task_struct(). Quite the
contrary it prevents optimizations. Move it to copy_thread()

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 arch/x86/kernel/process.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff mbox series

Patch

--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -87,7 +87,7 @@  int arch_dup_task_struct(struct task_str
 #ifdef CONFIG_VM86
 	dst->thread.vm86 = NULL;
 #endif
-	return fpu_clone(dst);
+	return 0;
 }
 
 /*
@@ -154,6 +154,8 @@  int copy_thread(unsigned long clone_flag
 	frame->flags = X86_EFLAGS_FIXED;
 #endif
 
+	fpu_clone(p);
+
 	/* Kernel thread ? */
 	if (unlikely(p->flags & PF_KTHREAD)) {
 		p->thread.pkru = pkru_get_init_value();