diff options
| author | Andy Lutomirski <luto@kernel.org> | 2015-06-25 18:43:57 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2015-07-06 15:23:26 +0200 |
| commit | 9261e050b686c9fe229cd9918d997b3caaf20e34 (patch) | |
| tree | 607b10051a6cee051998599b14d78347dedbffb4 /arch/x86/kernel/paravirt_patch_32.c | |
| parent | 881d7bf843d7139c6dfbffdec4903b3354423c49 (diff) | |
x86/asm/tsc, x86/paravirt: Remove read_tsc() and read_tscp() paravirt hooks
We've had ->read_tsc() and ->read_tscp() paravirt hooks since
the very beginning of paravirt, i.e.,
d3561b7fa0fb ("[PATCH] paravirt: header and stubs for paravirtualisation").
AFAICT, the only paravirt guest implementation that ever
replaced these calls was vmware, and it's gone. Arguably even
vmware shouldn't have hooked RDTSC -- we fully support systems
that don't have a TSC at all, so there's no point for a paravirt
implementation to pretend that we have a TSC but to replace it.
I also doubt that these hooks actually worked. Calls to rdtscl()
and rdtscll(), which respected the hooks, were used seemingly
interchangeably with native_read_tsc(), which did not.
Just remove them. If anyone ever needs them again, they can try
to make a case for why they need them.
Before, on a paravirt config:
text data bss dec hex filename
12618257 1816384 1093632 15528273 ecf151 vmlinux
After:
text data bss dec hex filename
12617207 1816384 1093632 15527223 eced37 vmlinux
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Huang Rui <ray.huang@amd.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Len Brown <lenb@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kvm ML <kvm@vger.kernel.org>
Cc: virtualization@lists.linux-foundation.org
Link: http://lkml.kernel.org/r/d08a2600fb298af163681e5efd8e599d889a5b97.1434501121.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kernel/paravirt_patch_32.c')
| -rw-r--r-- | arch/x86/kernel/paravirt_patch_32.c | 2 |
1 files changed, 0 insertions, 2 deletions
diff --git a/arch/x86/kernel/paravirt_patch_32.c b/arch/x86/kernel/paravirt_patch_32.c index e1b013696dde..c89f50a76e97 100644 --- a/arch/x86/kernel/paravirt_patch_32.c +++ b/arch/x86/kernel/paravirt_patch_32.c @@ -10,7 +10,6 @@ DEF_NATIVE(pv_mmu_ops, read_cr2, "mov %cr2, %eax"); DEF_NATIVE(pv_mmu_ops, write_cr3, "mov %eax, %cr3"); DEF_NATIVE(pv_mmu_ops, read_cr3, "mov %cr3, %eax"); DEF_NATIVE(pv_cpu_ops, clts, "clts"); -DEF_NATIVE(pv_cpu_ops, read_tsc, "rdtsc"); #if defined(CONFIG_PARAVIRT_SPINLOCKS) && defined(CONFIG_QUEUED_SPINLOCKS) DEF_NATIVE(pv_lock_ops, queued_spin_unlock, "movb $0, (%eax)"); @@ -52,7 +51,6 @@ unsigned native_patch(u8 type, u16 clobbers, void *ibuf, PATCH_SITE(pv_mmu_ops, read_cr3); PATCH_SITE(pv_mmu_ops, write_cr3); PATCH_SITE(pv_cpu_ops, clts); - PATCH_SITE(pv_cpu_ops, read_tsc); #if defined(CONFIG_PARAVIRT_SPINLOCKS) && defined(CONFIG_QUEUED_SPINLOCKS) case PARAVIRT_PATCH(pv_lock_ops.queued_spin_unlock): if (pv_is_native_spin_unlock()) { |