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Instrument the lazy FP context switch path:

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- fpevent_use is incremented the first time a process uses FP
  for the first time (note, FPUSED is inherited on fork, but
  cleared on exec).
- fpevent_reuse is incremented whenever a process that has previously
  used FP has to take a FEN trap in order to be able to use it again.
This commit is contained in:
thorpej 2001-07-14 05:10:38 +00:00
parent e31dfc4d0e
commit c022450f9c
1 changed files with 31 additions and 4 deletions
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33
sys/arch/alpha/alpha/trap.c
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@ -1,7 +1,7 @@
/* $NetBSD: trap.c,v 1.74 2001/07/12 23:35:43 thorpej Exp $ */ /* $NetBSD: trap.c,v 1.75 2001/07/14 05:10:38 thorpej Exp $ */
/*- /*-
* Copyright (c) 2000 The NetBSD Foundation, Inc. * Copyright (c) 2000, 2001 The NetBSD Foundation, Inc.
* All rights reserved. * All rights reserved.
* *
* This code is derived from software contributed to The NetBSD Foundation * This code is derived from software contributed to The NetBSD Foundation
@ -99,7 +99,7 @@
#include <sys/cdefs.h> /* RCS ID & Copyright macro defns */ #include <sys/cdefs.h> /* RCS ID & Copyright macro defns */
__KERNEL_RCSID(0, "$NetBSD: trap.c,v 1.74 2001/07/12 23:35:43 thorpej Exp $"); __KERNEL_RCSID(0, "$NetBSD: trap.c,v 1.75 2001/07/14 05:10:38 thorpej Exp $");
#include <sys/param.h> #include <sys/param.h>
#include <sys/systm.h> #include <sys/systm.h>
@ -123,6 +123,9 @@ __KERNEL_RCSID(0, "$NetBSD: trap.c,v 1.74 2001/07/12 23:35:43 thorpej Exp $");
static int unaligned_fixup(u_long, u_long, u_long, struct proc *); static int unaligned_fixup(u_long, u_long, u_long, struct proc *);
static int handle_opdec(struct proc *p, u_int64_t *ucodep); static int handle_opdec(struct proc *p, u_int64_t *ucodep);
struct evcnt fpevent_use;
struct evcnt fpevent_reuse;
/* /*
* Initialize the trap vectors for the current processor. * Initialize the trap vectors for the current processor.
*/ */
@ -146,6 +149,15 @@ trap_init(void)
*/ */
alpha_pal_wrmces(alpha_pal_rdmces() & alpha_pal_wrmces(alpha_pal_rdmces() &
~(ALPHA_MCES_DSC|ALPHA_MCES_DPC)); ~(ALPHA_MCES_DSC|ALPHA_MCES_DPC));
/*
* If this is the primary processor, initialize some trap
* event counters.
*/
evcnt_attach_dynamic(&fpevent_use, EVCNT_TYPE_MISC, NULL,
"FP", "proc use");
evcnt_attach_dynamic(&fpevent_reuse, EVCNT_TYPE_MISC, NULL,
"FP", "proc re-use");
} }
static void static void
@ -194,6 +206,8 @@ printtrap(const u_long a0, const u_long a1, const u_long a2,
framep->tf_regs[FRAME_PC]); framep->tf_regs[FRAME_PC]);
printf("CPU %lu ra = 0x%lx\n", cpu_id, printf("CPU %lu ra = 0x%lx\n", cpu_id,
framep->tf_regs[FRAME_RA]); framep->tf_regs[FRAME_RA]);
printf("CPU %lu pv = 0x%lx\n", cpu_id,
framep->tf_regs[FRAME_T12]);
printf("CPU %lu curproc = %p\n", cpu_id, curproc); printf("CPU %lu curproc = %p\n", cpu_id, curproc);
if (curproc != NULL) if (curproc != NULL)
printf("CPU %lu pid = %d, comm = %s\n", cpu_id, printf("CPU %lu pid = %d, comm = %s\n", cpu_id,
@ -568,7 +582,20 @@ alpha_enable_fp(struct proc *p, int check)
FPCPU_UNLOCK(&p->p_addr->u_pcb, s); FPCPU_UNLOCK(&p->p_addr->u_pcb, s);
/*
* Instrument FP usage -- if a process had not previously
* used FP, mark it as having used FP for the first time,
* and count this event.
*
* If a process has used FP, count a "used FP, and took
* a trap to use it again" event.
*/
if ((p->p_md.md_flags & MDP_FPUSED) == 0) {
atomic_add_ulong(&fpevent_use.ev_count, 1);
p->p_md.md_flags |= MDP_FPUSED; p->p_md.md_flags |= MDP_FPUSED;
} else
atomic_add_ulong(&fpevent_reuse.ev_count, 1);
alpha_pal_wrfen(1); alpha_pal_wrfen(1);
restorefpstate(&p->p_addr->u_pcb.pcb_fp); restorefpstate(&p->p_addr->u_pcb.pcb_fp);
} }