* [RFC PATCH REBASED 1/3] sh: Move fpu_counter into ARCH specific thread_struct [not found] <1379398639-27403-1-git-send-email-vgupta@synopsys.com> @ 2013-09-17 6:29 ` Vineet Gupta [not found] ` <20130917080017.GC12926@twins.programming.kicks-ass.net> 2013-10-01 10:45 ` Vineet Gupta 0 siblings, 2 replies; 3+ messages in thread From: Vineet Gupta @ 2013-09-17 6:29 UTC (permalink / raw) To: Ingo Molnar, Peter Zijlstra, Andrew Morton; +Cc: linux-arch Only a couple of arches (sh/x86) use fpu_counter in task_struct so it can be moved out into ARCH specific thread_struct, reducing the size of task_struct for other arches. Compile tested sh defconfig + sh4-linux-gcc (4.6.3) Signed-off-by: Vineet Gupta <vgupta@synopsys.com> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Michel Lespinasse <walken@google.com> Cc: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Jesper Nilsson <jesper.nilsson@axis.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: linux-kernel@vger.kernel.org Cc: linux-arch@vger.kernel.org Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: linux-sh@vger.kernel.org --- arch/sh/include/asm/fpu.h | 2 +- arch/sh/include/asm/processor_32.h | 10 ++++++++++ arch/sh/include/asm/processor_64.h | 10 ++++++++++ arch/sh/kernel/cpu/fpu.c | 2 +- arch/sh/kernel/process_32.c | 6 +++--- 5 files changed, 25 insertions(+), 5 deletions(-) diff --git a/arch/sh/include/asm/fpu.h b/arch/sh/include/asm/fpu.h index 06c4281..09fc2bc 100644 --- a/arch/sh/include/asm/fpu.h +++ b/arch/sh/include/asm/fpu.h @@ -46,7 +46,7 @@ static inline void __unlazy_fpu(struct task_struct *tsk, struct pt_regs *regs) save_fpu(tsk); release_fpu(regs); } else - tsk->fpu_counter = 0; + tsk->thread.fpu_counter = 0; } static inline void unlazy_fpu(struct task_struct *tsk, struct pt_regs *regs) diff --git a/arch/sh/include/asm/processor_32.h b/arch/sh/include/asm/processor_32.h index e699a12..18e0377 100644 --- a/arch/sh/include/asm/processor_32.h +++ b/arch/sh/include/asm/processor_32.h @@ -111,6 +111,16 @@ struct thread_struct { /* Extended processor state */ union thread_xstate *xstate; + + /* + * fpu_counter contains the number of consecutive context switches + * that the FPU is used. If this is over a threshold, the lazy fpu + * saving becomes unlazy to save the trap. This is an unsigned char + * so that after 256 times the counter wraps and the behavior turns + * lazy again; this to deal with bursty apps that only use FPU for + * a short time + */ + unsigned char fpu_counter; }; #define INIT_THREAD { \ diff --git a/arch/sh/include/asm/processor_64.h b/arch/sh/include/asm/processor_64.h index 1cc7d31..eedd4f6 100644 --- a/arch/sh/include/asm/processor_64.h +++ b/arch/sh/include/asm/processor_64.h @@ -126,6 +126,16 @@ struct thread_struct { /* floating point info */ union thread_xstate *xstate; + + /* + * fpu_counter contains the number of consecutive context switches + * that the FPU is used. If this is over a threshold, the lazy fpu + * saving becomes unlazy to save the trap. This is an unsigned char + * so that after 256 times the counter wraps and the behavior turns + * lazy again; this to deal with bursty apps that only use FPU for + * a short time + */ + unsigned char fpu_counter; }; #define INIT_MMAP \ diff --git a/arch/sh/kernel/cpu/fpu.c b/arch/sh/kernel/cpu/fpu.c index f8f7af5..4e33224 100644 --- a/arch/sh/kernel/cpu/fpu.c +++ b/arch/sh/kernel/cpu/fpu.c @@ -44,7 +44,7 @@ void __fpu_state_restore(void) restore_fpu(tsk); task_thread_info(tsk)->status |= TS_USEDFPU; - tsk->fpu_counter++; + tsk->thread.fpu_counter++; } void fpu_state_restore(struct pt_regs *regs) diff --git a/arch/sh/kernel/process_32.c b/arch/sh/kernel/process_32.c index ebd3933..2885fc9 100644 --- a/arch/sh/kernel/process_32.c +++ b/arch/sh/kernel/process_32.c @@ -156,7 +156,7 @@ int copy_thread(unsigned long clone_flags, unsigned long usp, #endif ti->addr_limit = KERNEL_DS; ti->status &= ~TS_USEDFPU; - p->fpu_counter = 0; + p->thread.fpu_counter = 0; return 0; } *childregs = *current_pt_regs(); @@ -189,7 +189,7 @@ __switch_to(struct task_struct *prev, struct task_struct *next) unlazy_fpu(prev, task_pt_regs(prev)); /* we're going to use this soon, after a few expensive things */ - if (next->fpu_counter > 5) + if (next->thread.fpu_counter > 5) prefetch(next_t->xstate); #ifdef CONFIG_MMU @@ -207,7 +207,7 @@ __switch_to(struct task_struct *prev, struct task_struct *next) * restore of the math state immediately to avoid the trap; the * chances of needing FPU soon are obviously high now */ - if (next->fpu_counter > 5) + if (next->thread.fpu_counter > 5) __fpu_state_restore(); return prev; -- 1.8.1.2 ^ permalink raw reply related [flat|nested] 3+ messages in thread
[parent not found: <20130917080017.GC12926@twins.programming.kicks-ass.net>]
[parent not found: <C2D7FE5348E1B147BCA15975FBA2307514C36B@IN01WEMBXA.internal.synopsys.com>]
* Re: [RFC PATCH REBASED 1/3] sh: Move fpu_counter into ARCH specific thread_struct [not found] ` <C2D7FE5348E1B147BCA15975FBA2307514C36B@IN01WEMBXA.internal.synopsys.com> @ 2013-09-17 8:25 ` Peter Zijlstra 0 siblings, 0 replies; 3+ messages in thread From: Peter Zijlstra @ 2013-09-17 8:25 UTC (permalink / raw) To: Vineet Gupta Cc: Ingo Molnar, Andrew Morton, linux-arch@vger.kernel.org, Paul Mundt, linux-sh On Tue, Sep 17, 2013 at 08:14:34AM +0000, Vineet Gupta wrote: > For some reason the email to Paul bounced last time as well > > --------------->8----------------------- > lethal@linux-sh.org<mailto:lethal@linux-sh.org>>: host mail.linux-sh.org[111.68.239.195] said: 550 5.7.1 > <lethal@linux-sh.org><mailto:lethal@linux-sh.org>... Relaying denied. Proper authentication required. > (in reply to RCPT TO command) > --------------->8----------------------- > > Did you get that too after sending this CCed email to him. Yep.. :/ ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [RFC PATCH REBASED 1/3] sh: Move fpu_counter into ARCH specific thread_struct 2013-09-17 6:29 ` [RFC PATCH REBASED 1/3] sh: Move fpu_counter into ARCH specific thread_struct Vineet Gupta [not found] ` <20130917080017.GC12926@twins.programming.kicks-ass.net> @ 2013-10-01 10:45 ` Vineet Gupta 1 sibling, 0 replies; 3+ messages in thread From: Vineet Gupta @ 2013-10-01 10:45 UTC (permalink / raw) To: Paul Mundt, linux-sh Cc: Ingo Molnar, Peter Zijlstra, Andrew Morton, linux-arch, lkml Hi Paul/SH folks. Would appreciate your ACK/NAK on this. Thx, -Vineet On 09/17/2013 11:47 AM, Vineet Gupta wrote: > Only a couple of arches (sh/x86) use fpu_counter in task_struct so it > can be moved out into ARCH specific thread_struct, reducing the size of > task_struct for other arches. > > Compile tested sh defconfig + sh4-linux-gcc (4.6.3) > > Signed-off-by: Vineet Gupta <vgupta@synopsys.com> > Cc: Paul Mundt <lethal@linux-sh.org> > Cc: Michel Lespinasse <walken@google.com> > Cc: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com> > Cc: Al Viro <viro@zeniv.linux.org.uk> > Cc: Andrew Morton <akpm@linux-foundation.org> > Cc: Jesper Nilsson <jesper.nilsson@axis.com> > Cc: Chris Metcalf <cmetcalf@tilera.com> > Cc: "David S. Miller" <davem@davemloft.net> > Cc: linux-kernel@vger.kernel.org > Cc: linux-arch@vger.kernel.org > Cc: Ingo Molnar <mingo@redhat.com> > Cc: Peter Zijlstra <peterz@infradead.org> > Cc: linux-sh@vger.kernel.org > --- > arch/sh/include/asm/fpu.h | 2 +- > arch/sh/include/asm/processor_32.h | 10 ++++++++++ > arch/sh/include/asm/processor_64.h | 10 ++++++++++ > arch/sh/kernel/cpu/fpu.c | 2 +- > arch/sh/kernel/process_32.c | 6 +++--- > 5 files changed, 25 insertions(+), 5 deletions(-) > > diff --git a/arch/sh/include/asm/fpu.h b/arch/sh/include/asm/fpu.h > index 06c4281..09fc2bc 100644 > --- a/arch/sh/include/asm/fpu.h > +++ b/arch/sh/include/asm/fpu.h > @@ -46,7 +46,7 @@ static inline void __unlazy_fpu(struct task_struct *tsk, struct pt_regs *regs) > save_fpu(tsk); > release_fpu(regs); > } else > - tsk->fpu_counter = 0; > + tsk->thread.fpu_counter = 0; > } > > static inline void unlazy_fpu(struct task_struct *tsk, struct pt_regs *regs) > diff --git a/arch/sh/include/asm/processor_32.h b/arch/sh/include/asm/processor_32.h > index e699a12..18e0377 100644 > --- a/arch/sh/include/asm/processor_32.h > +++ b/arch/sh/include/asm/processor_32.h > @@ -111,6 +111,16 @@ struct thread_struct { > > /* Extended processor state */ > union thread_xstate *xstate; > + > + /* > + * fpu_counter contains the number of consecutive context switches > + * that the FPU is used. If this is over a threshold, the lazy fpu > + * saving becomes unlazy to save the trap. This is an unsigned char > + * so that after 256 times the counter wraps and the behavior turns > + * lazy again; this to deal with bursty apps that only use FPU for > + * a short time > + */ > + unsigned char fpu_counter; > }; > > #define INIT_THREAD { \ > diff --git a/arch/sh/include/asm/processor_64.h b/arch/sh/include/asm/processor_64.h > index 1cc7d31..eedd4f6 100644 > --- a/arch/sh/include/asm/processor_64.h > +++ b/arch/sh/include/asm/processor_64.h > @@ -126,6 +126,16 @@ struct thread_struct { > > /* floating point info */ > union thread_xstate *xstate; > + > + /* > + * fpu_counter contains the number of consecutive context switches > + * that the FPU is used. If this is over a threshold, the lazy fpu > + * saving becomes unlazy to save the trap. This is an unsigned char > + * so that after 256 times the counter wraps and the behavior turns > + * lazy again; this to deal with bursty apps that only use FPU for > + * a short time > + */ > + unsigned char fpu_counter; > }; > > #define INIT_MMAP \ > diff --git a/arch/sh/kernel/cpu/fpu.c b/arch/sh/kernel/cpu/fpu.c > index f8f7af5..4e33224 100644 > --- a/arch/sh/kernel/cpu/fpu.c > +++ b/arch/sh/kernel/cpu/fpu.c > @@ -44,7 +44,7 @@ void __fpu_state_restore(void) > restore_fpu(tsk); > > task_thread_info(tsk)->status |= TS_USEDFPU; > - tsk->fpu_counter++; > + tsk->thread.fpu_counter++; > } > > void fpu_state_restore(struct pt_regs *regs) > diff --git a/arch/sh/kernel/process_32.c b/arch/sh/kernel/process_32.c > index ebd3933..2885fc9 100644 > --- a/arch/sh/kernel/process_32.c > +++ b/arch/sh/kernel/process_32.c > @@ -156,7 +156,7 @@ int copy_thread(unsigned long clone_flags, unsigned long usp, > #endif > ti->addr_limit = KERNEL_DS; > ti->status &= ~TS_USEDFPU; > - p->fpu_counter = 0; > + p->thread.fpu_counter = 0; > return 0; > } > *childregs = *current_pt_regs(); > @@ -189,7 +189,7 @@ __switch_to(struct task_struct *prev, struct task_struct *next) > unlazy_fpu(prev, task_pt_regs(prev)); > > /* we're going to use this soon, after a few expensive things */ > - if (next->fpu_counter > 5) > + if (next->thread.fpu_counter > 5) > prefetch(next_t->xstate); > > #ifdef CONFIG_MMU > @@ -207,7 +207,7 @@ __switch_to(struct task_struct *prev, struct task_struct *next) > * restore of the math state immediately to avoid the trap; the > * chances of needing FPU soon are obviously high now > */ > - if (next->fpu_counter > 5) > + if (next->thread.fpu_counter > 5) > __fpu_state_restore(); > > return prev; > ^ permalink raw reply [flat|nested] 3+ messages in thread
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2013-09-17 6:29 ` [RFC PATCH REBASED 1/3] sh: Move fpu_counter into ARCH specific thread_struct Vineet Gupta
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2013-09-17 8:25 ` Peter Zijlstra
2013-10-01 10:45 ` Vineet Gupta
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