| Date | Tue, 26 Sep 2017 01:27:48 -0700 | From | tip-bot for Ingo Molnar <> | Subject | [tip:x86/fpu] x86/fpu: Make the fpu state change in fpu__clear() scheduler-atomic |
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Commit-ID: a10b6a16cdad88170f546d008c77453cddf918e6 Gitweb: http://git.kernel.org/tip/a10b6a16cdad88170f546d008c77453cddf918e6 Author: Ingo Molnar <mingo@kernel.org> AuthorDate: Sat, 23 Sep 2017 14:59:59 +0200 Committer: Ingo Molnar <mingo@kernel.org> CommitDate: Sun, 24 Sep 2017 13:04:33 +0200
x86/fpu: Make the fpu state change in fpu__clear() scheduler-atomic
Do this temporarily only, to make it easier to change the FPU state machine, in particular this change couples the fpu->fpregs_active and fpu->fpstate_active states: they are only set/cleared together (as far as the scheduler sees them).
This will be removed by later patches.
Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Eric Biggers <ebiggers3@gmail.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yu-cheng Yu <yu-cheng.yu@intel.com> Link: http://lkml.kernel.org/r/20170923130016.21448-17-mingo@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org> --- arch/x86/kernel/fpu/core.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c index bad5724..b7dc383 100644 --- a/arch/x86/kernel/fpu/core.c +++ b/arch/x86/kernel/fpu/core.c @@ -462,9 +462,11 @@ void fpu__clear(struct fpu *fpu) * Make sure fpstate is cleared and initialized. */ if (static_cpu_has(X86_FEATURE_FPU)) { + preempt_disable(); fpu__activate_curr(fpu); user_fpu_begin(); copy_init_fpstate_to_fpregs(); + preempt_enable(); } }
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