Hello?
I've been running with this diff since July without any issues (i386 &
amd64).
* Alexander Polakov <p...@sdf.org> [121213 18:34]:
> This diff reduces IPI traffic for a case when process A is sending
> a lot of signals to process B running on a different CPU. userret()
> delivers all process signals at once, so there is no need to send
> an interrupt for every signal.
>
> The problem was noticed by rtorrent 0.9.2 users, which does exactly
> this, which led to process/system hangs and slowness.
>
> Tested and known to help on amd64 by me and dcoppa@.
>
> Index: amd64/amd64/machdep.c
> ===================================================================
> RCS file: /cvs/src/sys/arch/amd64/amd64/machdep.c,v
> retrieving revision 1.155
> diff -u -r1.155 machdep.c
> --- amd64/amd64/machdep.c 4 Jun 2012 15:19:47 -0000 1.155
> +++ amd64/amd64/machdep.c 23 Jul 2012 13:49:40 -0000
> @@ -690,8 +690,10 @@
> void
> signotify(struct proc *p)
> {
> - aston(p);
> - cpu_unidle(p->p_cpu);
> + if (!isastset(p)) {
> + aston(p);
> + cpu_unidle(p->p_cpu);
> + }
> }
>
> #ifdef MULTIPROCESSOR
> Index: amd64/include/cpu.h
> ===================================================================
> RCS file: /cvs/src/sys/arch/amd64/include/cpu.h,v
> retrieving revision 1.73
> diff -u -r1.73 cpu.h
> --- amd64/include/cpu.h 17 Apr 2012 16:02:33 -0000 1.73
> +++ amd64/include/cpu.h 23 Jul 2012 13:49:40 -0000
> @@ -213,6 +213,7 @@
> #endif
>
> #define aston(p) ((p)->p_md.md_astpending = 1)
> +#define isastset(p) ((p)->p_md.md_astpending == 1)
>
> #define curpcb curcpu()->ci_curpcb
>
> Index: hppa/hppa/machdep.c
> ===================================================================
> RCS file: /cvs/src/sys/arch/hppa/hppa/machdep.c,v
> retrieving revision 1.206
> diff -u -r1.206 machdep.c
> --- hppa/hppa/machdep.c 21 Jun 2012 00:56:59 -0000 1.206
> +++ hppa/hppa/machdep.c 23 Jul 2012 13:49:40 -0000
> @@ -1399,8 +1399,10 @@
> void
> signotify(struct proc *p)
> {
> - setsoftast(p);
> - cpu_unidle(p->p_cpu);
> + if (!isastset(p)) {
> + setsoftast(p);
> + cpu_unidle(p->p_cpu);
> + }
> }
>
> /*
> Index: hppa/include/intr.h
> ===================================================================
> RCS file: /cvs/src/sys/arch/hppa/include/intr.h,v
> retrieving revision 1.37
> diff -u -r1.37 intr.h
> --- hppa/include/intr.h 14 Jan 2011 13:20:06 -0000 1.37
> +++ hppa/include/intr.h 23 Jul 2012 13:49:40 -0000
> @@ -157,7 +157,8 @@
> int hppa_ipi_broadcast(u_long);
> #endif
>
> -#define setsoftast(p) (p->p_md.md_astpending = 1)
> +#define setsoftast(p) ((p)->p_md.md_astpending = 1)
> +#define isastset(p) ((p)->p_md.md_astpending == 1)
>
> void *softintr_establish(int, void (*)(void *), void *);
> void softintr_disestablish(void *);
> Index: i386/i386/machdep.c
> ===================================================================
> RCS file: /cvs/src/sys/arch/i386/i386/machdep.c,v
> retrieving revision 1.510
> diff -u -r1.510 machdep.c
> --- i386/i386/machdep.c 23 May 2012 08:23:43 -0000 1.510
> +++ i386/i386/machdep.c 23 Jul 2012 13:49:40 -0000
> @@ -2420,8 +2420,10 @@
> void
> signotify(struct proc *p)
> {
> - aston(p);
> - cpu_unidle(p->p_cpu);
> + if (!isastset(p)) {
> + aston(p);
> + cpu_unidle(p->p_cpu);
> + }
> }
>
> #ifdef MULTIPROCESSOR
> Index: i386/include/cpu.h
> ===================================================================
> RCS file: /cvs/src/sys/arch/i386/include/cpu.h,v
> retrieving revision 1.122
> diff -u -r1.122 cpu.h
> --- i386/include/cpu.h 27 Mar 2012 06:44:01 -0000 1.122
> +++ i386/include/cpu.h 23 Jul 2012 13:49:41 -0000
> @@ -226,6 +226,7 @@
> #endif
>
> #define aston(p) ((p)->p_md.md_astpending = 1)
> +#define isastset(p) ((p)->p_md.md_astpending == 1)
>
> #define curpcb curcpu()->ci_curpcb
>
> Index: m88k/include/cpu.h
> ===================================================================
> RCS file: /cvs/src/sys/arch/m88k/include/cpu.h,v
> retrieving revision 1.54
> diff -u -r1.54 cpu.h
> --- m88k/include/cpu.h 25 Oct 2011 18:38:06 -0000 1.54
> +++ m88k/include/cpu.h 23 Jul 2012 13:49:41 -0000
> @@ -256,6 +256,7 @@
> (((struct cpu_info *)(framep)->tf.tf_cpu)->ci_intrdepth > 1)
>
> #define aston(p) ((p)->p_md.md_astpending = 1)
> +#define isastset(p) ((p)->p_md.md_astpending == 1)
>
> /*
> * This is used during profiling to integrate system time.
> Index: m88k/m88k/m88k_machdep.c
> ===================================================================
> RCS file: /cvs/src/sys/arch/m88k/m88k/m88k_machdep.c,v
> retrieving revision 1.52
> diff -u -r1.52 m88k_machdep.c
> --- m88k/m88k/m88k_machdep.c 23 Mar 2012 15:51:26 -0000 1.52
> +++ m88k/m88k/m88k_machdep.c 23 Jul 2012 13:49:41 -0000
> @@ -314,8 +314,10 @@
> void
> signotify(struct proc *p)
> {
> - aston(p);
> - cpu_unidle(p->p_cpu);
> + if (!isastset(p)) {
> + aston(p);
> + cpu_unidle(p->p_cpu);
> + }
> }
>
> #ifdef MULTIPROCESSOR
> Index: macppc/macppc/machdep.c
> ===================================================================
> RCS file: /cvs/src/sys/arch/macppc/macppc/machdep.c,v
> retrieving revision 1.131
> diff -u -r1.131 machdep.c
> --- macppc/macppc/machdep.c 29 Aug 2011 20:21:44 -0000 1.131
> +++ macppc/macppc/machdep.c 23 Jul 2012 13:49:41 -0000
> @@ -935,8 +935,10 @@
> void
> signotify(struct proc *p)
> {
> - aston(p);
> - cpu_unidle(p->p_cpu);
> + if (!isastset(p)) {
> + aston(p);
> + cpu_unidle(p->p_cpu);
> + }
> }
>
> #ifdef MULTIPROCESSOR
> Index: mips64/include/cpu.h
> ===================================================================
> RCS file: /cvs/src/sys/arch/mips64/include/cpu.h,v
> retrieving revision 1.83
> diff -u -r1.83 cpu.h
> --- mips64/include/cpu.h 14 Jul 2012 19:50:11 -0000 1.83
> +++ mips64/include/cpu.h 23 Jul 2012 13:49:41 -0000
> @@ -511,12 +511,20 @@
> * process as soon as possible.
> */
> #ifdef MULTIPROCESSOR
> -#define signotify(p) (aston(p), cpu_unidle(p->p_cpu))
> +static __inline void
> +signotify(struct proc *p)
> +{
> + if (!isastset(p)) {
> + aston(p);
> + cpu_unidle(p->p_cpu);
> + }
> +}
> #else
> #define signotify(p) aston(p)
> #endif
>
> -#define aston(p) p->p_md.md_astpending = 1
> +#define aston(p) ((p)->p_md.md_astpending = 1)
> +#define isastset(p) ((p)->p_md.md_astpending == 1)
>
> #endif /* _KERNEL && !_LOCORE */
>
> Index: powerpc/include/cpu.h
> ===================================================================
> RCS file: /cvs/src/sys/arch/powerpc/include/cpu.h,v
> retrieving revision 1.46
> diff -u -r1.46 cpu.h
> --- powerpc/include/cpu.h 28 Sep 2010 20:27:55 -0000 1.46
> +++ powerpc/include/cpu.h 23 Jul 2012 13:49:41 -0000
> @@ -155,6 +155,7 @@
> #define DELAY(n) delay(n)
>
> #define aston(p) ((p)->p_md.md_astpending = 1)
> +#define isastset(p) ((p)->p_md.md_astpending == 1)
>
> /*
> * Preempt the current process if in interrupt from user mode,
> Index: sparc64/include/cpu.h
> ===================================================================
> RCS file: /cvs/src/sys/arch/sparc64/include/cpu.h,v
> retrieving revision 1.78
> diff -u -r1.78 cpu.h
> --- sparc64/include/cpu.h 6 Jul 2011 22:26:44 -0000 1.78
> +++ sparc64/include/cpu.h 23 Jul 2012 13:49:41 -0000
> @@ -226,7 +226,7 @@
> extern void (*cpu_start_clock)(void);
>
> #define aston(p) ((p)->p_md.md_astpending = 1)
> -
> +#define isastset(p) ((p)->p_md.md_astpending == 1)
> /*
> * Preempt the current process if in interrupt from user mode,
> * or after the current trap/syscall if in system mode.
> Index: sparc64/sparc64/machdep.c
> ===================================================================
> RCS file: /cvs/src/sys/arch/sparc64/sparc64/machdep.c,v
> retrieving revision 1.138
> diff -u -r1.138 machdep.c
> --- sparc64/sparc64/machdep.c 9 May 2012 18:34:21 -0000 1.138
> +++ sparc64/sparc64/machdep.c 23 Jul 2012 13:49:42 -0000
> @@ -613,8 +613,10 @@
> void
> signotify(struct proc *p)
> {
> - aston(p);
> - cpu_unidle(p->p_cpu);
> + if (!isastset(p)) {
> + aston(p);
> + cpu_unidle(p->p_cpu);
> + }
> }
>
> int waittime = -1;
>
--
Alexander Polakov | plhk.ru
