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Message-Id: <1225182678.1685.68.camel@ymzhang>
Date: Tue, 28 Oct 2008 16:31:18 +0800
From: "Zhang, Yanmin" <yanmin_zhang@...ux.intel.com>
To: Ingo Molnar <mingo@...e.hu>
Cc: LKML <linux-kernel@...r.kernel.org>,
"H. Peter Anvin" <hpa@...or.com>,
Suresh Siddha <suresh.b.siddha@...el.com>,
Roland McGrath <roland@...hat.com>,
Hiroshi Shimamoto <h-shimamoto@...jp.nec.com>,
Yinghai Lu <yinghai@...nel.org>
Subject: Re: cpu2000(both float and int) 13% regression with 2.6.28-rc1
On Tue, 2008-10-28 at 09:03 +0100, Ingo Molnar wrote:
> * Zhang, Yanmin <yanmin_zhang@...ux.intel.com> wrote:
>
> > Comparing with 2.6.27, cpu2000 (both float and int) has about 13% regression
> > with 2.6.28-rc1 on my new-model x86-64 machine.
> >
> > I bisected down to below patch.
> >
> > commit 0afe2db21394820d32646a695eccf3fbfe6ab5c7
> > Merge: d847059... 43603c8...
> > Author: Ingo Molnar <mingo@...e.hu>
> > Date: Sat Oct 11 20:23:20 2008 +0200
> >
> > Merge branch 'x86/unify-cpu-detect' into x86-v28-for-linus-phase4-D
> >
> > Conflicts:
> > arch/x86/kernel/cpu/common.c
> > arch/x86/kernel/signal_64.c
> > include/asm-x86/cpufeature.h
> >
> >
> > When I tried to revert it against 2.6.28-rc2, there are many conflictions.
>
> My guess right now is that it's the merge commit's doing, see the diff
> below. Could you undo just the restore_sigcontext() chunk of it, in
> arch/x86/kernel/signal_64.c:
I failed to apply the patch. When I tried to manually copy the source codes
from 2.6.27 to 2.6.28-rc2, I found there are many dependence on xsave, such like
TS_XSAVE, so restore might not match with save.
>
> @@@ -157,20 -96,9 +94,9 @@@ restore_sigcontext(struct pt_regs *regs
>
> I've attached it as a patch below, apply it with "patch -p1 -R"
>
> (I've also attached the full merge commit further below - just in case
> it's in another portion of it.)
>
> Ingo
>
> ---------------->
>
> diff --cc arch/x86/kernel/signal_64.c
> index 694aa88,4665b59..823a55b
> --- a/arch/x86/kernel/signal_64.c
> +++ b/arch/x86/kernel/signal_64.c
> @@@ -157,20 -96,9 +94,9 @@@ restore_sigcontext(struct pt_regs *regs
> }
>
> {
> - struct _fpstate __user * buf;
> + struct _fpstate __user *buf;
> err |= __get_user(buf, &sc->fpstate);
> -
> - if (buf) {
> - if (!access_ok(VERIFY_READ, buf, sizeof(*buf)))
> - goto badframe;
> - err |= restore_i387(buf);
> - } else {
> - struct task_struct *me = current;
> - if (used_math()) {
> - clear_fpu(me);
> - clear_used_math();
> - }
> - }
> + err |= restore_i387_xstate(buf);
> }
>
> err |= __get_user(*pax, &sc->ax);
>
> ------------------->
> commit 0afe2db21394820d32646a695eccf3fbfe6ab5c7
> Merge: d847059... 43603c8...
> Author: Ingo Molnar <mingo@...e.hu>
> Date: Sat Oct 11 20:23:20 2008 +0200
>
> Merge branch 'x86/unify-cpu-detect' into x86-v28-for-linus-phase4-D
>
> Conflicts:
> arch/x86/kernel/cpu/common.c
> arch/x86/kernel/signal_64.c
> include/asm-x86/cpufeature.h
>
> diff --cc arch/x86/kernel/sigframe.h
> index 8b4956e,6dd7e2b..cc673aa
> --- a/arch/x86/kernel/sigframe.h
> +++ b/arch/x86/kernel/sigframe.h
> @@@ -23,10 -32,6 +32,11 @@@ struct rt_sigframe
> char __user *pretcode;
> struct ucontext uc;
> struct siginfo info;
> + /* fp state follows here */
> };
> +
> +int ia32_setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
> + sigset_t *set, struct pt_regs *regs);
> +int ia32_setup_frame(int sig, struct k_sigaction *ka,
> + sigset_t *set, struct pt_regs *regs);
> #endif
> diff --cc arch/x86/kernel/signal_64.c
> index 694aa88,4665b59..823a55b
> --- a/arch/x86/kernel/signal_64.c
> +++ b/arch/x86/kernel/signal_64.c
> @@@ -157,20 -96,9 +94,9 @@@ restore_sigcontext(struct pt_regs *regs
> }
>
> {
> - struct _fpstate __user * buf;
> + struct _fpstate __user *buf;
> err |= __get_user(buf, &sc->fpstate);
> -
> - if (buf) {
> - if (!access_ok(VERIFY_READ, buf, sizeof(*buf)))
> - goto badframe;
> - err |= restore_i387(buf);
> - } else {
> - struct task_struct *me = current;
> - if (used_math()) {
> - clear_fpu(me);
> - clear_used_math();
> - }
> - }
> + err |= restore_i387_xstate(buf);
> }
>
> err |= __get_user(*pax, &sc->ax);
> @@@ -273,10 -197,10 +196,10 @@@ get_stack(struct k_sigaction *ka, struc
> }
>
> static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
> - sigset_t *set, struct pt_regs * regs)
> + sigset_t *set, struct pt_regs *regs)
> {
> struct rt_sigframe __user *frame;
> - struct _fpstate __user *fp = NULL;
> + void __user *fp = NULL;
> int err = 0;
> struct task_struct *me = current;
>
> @@@ -285,11 -209,8 +208,8 @@@
> frame = (void __user *)round_down(
> (unsigned long)fp - sizeof(struct rt_sigframe), 16) - 8;
>
> - if (!access_ok(VERIFY_WRITE, fp, sizeof(struct _fpstate)))
> - goto give_sigsegv;
> -
> - if (save_i387(fp) < 0)
> + if (save_i387_xstate(fp) < 0)
> - err |= -1;
> + err |= -1;
> } else
> frame = get_stack(ka, regs, sizeof(struct rt_sigframe)) - 8;
>
> @@@ -301,9 -222,12 +221,12 @@@
> if (err)
> goto give_sigsegv;
> }
> -
> +
> /* Create the ucontext. */
> - err |= __put_user(0, &frame->uc.uc_flags);
> + if (cpu_has_xsave)
> + err |= __put_user(UC_FP_XSTATE, &frame->uc.uc_flags);
> + else
> + err |= __put_user(0, &frame->uc.uc_flags);
> err |= __put_user(0, &frame->uc.uc_link);
> err |= __put_user(me->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
> err |= __put_user(sas_ss_flags(regs->sp),
> diff --cc include/asm-x86/cpufeature.h
> index 065c6a8,8d45690..adfeae6
> --- a/include/asm-x86/cpufeature.h
> +++ b/include/asm-x86/cpufeature.h
> @@@ -64,49 -72,61 +72,63 @@@
> #define X86_FEATURE_CYRIX_ARR (3*32+ 2) /* Cyrix ARRs (= MTRRs) */
> #define X86_FEATURE_CENTAUR_MCR (3*32+ 3) /* Centaur MCRs (= MTRRs) */
> /* cpu types for specific tunings: */
> - #define X86_FEATURE_K8 (3*32+ 4) /* Opteron, Athlon64 */
> - #define X86_FEATURE_K7 (3*32+ 5) /* Athlon */
> - #define X86_FEATURE_P3 (3*32+ 6) /* P3 */
> - #define X86_FEATURE_P4 (3*32+ 7) /* P4 */
> + #define X86_FEATURE_K8 (3*32+ 4) /* "" Opteron, Athlon64 */
> + #define X86_FEATURE_K7 (3*32+ 5) /* "" Athlon */
> + #define X86_FEATURE_P3 (3*32+ 6) /* "" P3 */
> + #define X86_FEATURE_P4 (3*32+ 7) /* "" P4 */
> #define X86_FEATURE_CONSTANT_TSC (3*32+ 8) /* TSC ticks at a constant rate */
> #define X86_FEATURE_UP (3*32+ 9) /* smp kernel running on up */
> - #define X86_FEATURE_FXSAVE_LEAK (3*32+10) /* FXSAVE leaks FOP/FIP/FOP */
> + #define X86_FEATURE_FXSAVE_LEAK (3*32+10) /* "" FXSAVE leaks FOP/FIP/FOP */
> #define X86_FEATURE_ARCH_PERFMON (3*32+11) /* Intel Architectural PerfMon */
> ++#define X86_FEATURE_NOPL (3*32+20) /* The NOPL (0F 1F) instructions */
> #define X86_FEATURE_PEBS (3*32+12) /* Precise-Event Based Sampling */
> #define X86_FEATURE_BTS (3*32+13) /* Branch Trace Store */
> - #define X86_FEATURE_SYSCALL32 (3*32+14) /* syscall in ia32 userspace */
> - #define X86_FEATURE_SYSENTER32 (3*32+15) /* sysenter in ia32 userspace */
> - #define X86_FEATURE_REP_GOOD (3*32+16) /* rep microcode works well on this CPU */
> - #define X86_FEATURE_MFENCE_RDTSC (3*32+17) /* Mfence synchronizes RDTSC */
> - #define X86_FEATURE_LFENCE_RDTSC (3*32+18) /* Lfence synchronizes RDTSC */
> - #define X86_FEATURE_11AP (3*32+19) /* Bad local APIC aka 11AP */
> + #define X86_FEATURE_SYSCALL32 (3*32+14) /* "" syscall in ia32 userspace */
> + #define X86_FEATURE_SYSENTER32 (3*32+15) /* "" sysenter in ia32 userspace */
> + #define X86_FEATURE_REP_GOOD (3*32+16) /* rep microcode works well */
> + #define X86_FEATURE_MFENCE_RDTSC (3*32+17) /* "" Mfence synchronizes RDTSC */
> + #define X86_FEATURE_LFENCE_RDTSC (3*32+18) /* "" Lfence synchronizes RDTSC */
> + #define X86_FEATURE_11AP (3*32+19) /* "" Bad local APIC aka 11AP */
> #define X86_FEATURE_NOPL (3*32+20) /* The NOPL (0F 1F) instructions */
> +#define X86_FEATURE_AMDC1E (3*32+21) /* AMD C1E detected */
> + #define X86_FEATURE_XTOPOLOGY (3*32+21) /* cpu topology enum extensions */
>
> /* Intel-defined CPU features, CPUID level 0x00000001 (ecx), word 4 */
> - #define X86_FEATURE_XMM3 (4*32+ 0) /* Streaming SIMD Extensions-3 */
> - #define X86_FEATURE_MWAIT (4*32+ 3) /* Monitor/Mwait support */
> - #define X86_FEATURE_DSCPL (4*32+ 4) /* CPL Qualified Debug Store */
> + #define X86_FEATURE_XMM3 (4*32+ 0) /* "pni" SSE-3 */
> + #define X86_FEATURE_PCLMULQDQ (4*32+ 1) /* PCLMULQDQ instruction */
> + #define X86_FEATURE_DTES64 (4*32+ 2) /* 64-bit Debug Store */
> + #define X86_FEATURE_MWAIT (4*32+ 3) /* "monitor" Monitor/Mwait support */
> + #define X86_FEATURE_DSCPL (4*32+ 4) /* "ds_cpl" CPL Qual. Debug Store */
> + #define X86_FEATURE_VMX (4*32+ 5) /* Hardware virtualization */
> + #define X86_FEATURE_SMX (4*32+ 6) /* Safer mode */
> #define X86_FEATURE_EST (4*32+ 7) /* Enhanced SpeedStep */
> #define X86_FEATURE_TM2 (4*32+ 8) /* Thermal Monitor 2 */
> + #define X86_FEATURE_SSSE3 (4*32+ 9) /* Supplemental SSE-3 */
> #define X86_FEATURE_CID (4*32+10) /* Context ID */
> + #define X86_FEATURE_FMA (4*32+12) /* Fused multiply-add */
> #define X86_FEATURE_CX16 (4*32+13) /* CMPXCHG16B */
> #define X86_FEATURE_XTPR (4*32+14) /* Send Task Priority Messages */
> + #define X86_FEATURE_PDCM (4*32+15) /* Performance Capabilities */
> #define X86_FEATURE_DCA (4*32+18) /* Direct Cache Access */
> + #define X86_FEATURE_XMM4_1 (4*32+19) /* "sse4_1" SSE-4.1 */
> + #define X86_FEATURE_XMM4_2 (4*32+20) /* "sse4_2" SSE-4.2 */
> #define X86_FEATURE_X2APIC (4*32+21) /* x2APIC */
> - #define X86_FEATURE_XMM4_2 (4*32+20) /* Streaming SIMD Extensions-4.2 */
> + #define X86_FEATURE_AES (4*32+25) /* AES instructions */
> + #define X86_FEATURE_XSAVE (4*32+26) /* XSAVE/XRSTOR/XSETBV/XGETBV */
> + #define X86_FEATURE_OSXSAVE (4*32+27) /* "" XSAVE enabled in the OS */
> + #define X86_FEATURE_AVX (4*32+28) /* Advanced Vector Extensions */
>
> /* VIA/Cyrix/Centaur-defined CPU features, CPUID level 0xC0000001, word 5 */
> - #define X86_FEATURE_XSTORE (5*32+ 2) /* on-CPU RNG present (xstore insn) */
> - #define X86_FEATURE_XSTORE_EN (5*32+ 3) /* on-CPU RNG enabled */
> - #define X86_FEATURE_XCRYPT (5*32+ 6) /* on-CPU crypto (xcrypt insn) */
> - #define X86_FEATURE_XCRYPT_EN (5*32+ 7) /* on-CPU crypto enabled */
> + #define X86_FEATURE_XSTORE (5*32+ 2) /* "rng" RNG present (xstore) */
> + #define X86_FEATURE_XSTORE_EN (5*32+ 3) /* "rng_en" RNG enabled */
> + #define X86_FEATURE_XCRYPT (5*32+ 6) /* "ace" on-CPU crypto (xcrypt) */
> + #define X86_FEATURE_XCRYPT_EN (5*32+ 7) /* "ace_en" on-CPU crypto enabled */
> #define X86_FEATURE_ACE2 (5*32+ 8) /* Advanced Cryptography Engine v2 */
> #define X86_FEATURE_ACE2_EN (5*32+ 9) /* ACE v2 enabled */
> - #define X86_FEATURE_PHE (5*32+ 10) /* PadLock Hash Engine */
> - #define X86_FEATURE_PHE_EN (5*32+ 11) /* PHE enabled */
> - #define X86_FEATURE_PMM (5*32+ 12) /* PadLock Montgomery Multiplier */
> - #define X86_FEATURE_PMM_EN (5*32+ 13) /* PMM enabled */
> + #define X86_FEATURE_PHE (5*32+10) /* PadLock Hash Engine */
> + #define X86_FEATURE_PHE_EN (5*32+11) /* PHE enabled */
> + #define X86_FEATURE_PMM (5*32+12) /* PadLock Montgomery Multiplier */
> + #define X86_FEATURE_PMM_EN (5*32+13) /* PMM enabled */
>
> /* More extended AMD flags: CPUID level 0x80000001, ecx, word 6 */
> #define X86_FEATURE_LAHF_LM (6*32+ 0) /* LAHF/SAHF in long mode */
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