Stephane,
On Monday 03 September 2007 16:21, Stephane Eranian wrote:
> Vivek,
>
> Look at notify_self2.c. It is not system-wide but it can be converted
> fairly easily.
I tried running notify_self2.c by making it run in system wide mode but it
also doesn't generate any SIGIO signals. Please review some minor changes in
this file (tagged with VT_ ) and let me know what else needs to be done.
Thanks a lot !
Regards,
Vivek
PS: pfmon --version
pfmon version 3.2 Date: Jan 16 2007
Copyright (C) 2001-2004 Hewlett-Packard Company
Libfpm is the latest. I am using old_interface_example/notify_self2.c
> On Mon, Sep 03, 2007 at 04:13:35PM -0400, [EMAIL PROTECTED] wrote:
> > Stephane,
> >
> > On Monday 03 September 2007 13:36, Stephane Eranian wrote:
> > > Vivek,
> > >
> > > On Mon, Sep 03, 2007 at 01:27:54PM -0400, [EMAIL PROTECTED] wrote:
> > > > Stephane,
> > > >
> > > > Thanks a lot for such a prompt reply ! Please see my inlined
> > > > comments.
> > > >
> > > > On Monday 03 September 2007 12:28, Stephane Eranian wrote:
> > > > > Vivek,
> > > > >
> > > > > On Mon, Sep 03, 2007 at 11:49:11AM -0400, [EMAIL PROTECTED] wrote:
> > > > > > Hi !
> > > > > >
> > > > > > I am trying to use perfmon on Itanium 2 server (HP's testdrive
> > > > > > td178 machine ). I have a multi-threaded program but each thread
> > > > > > can be pinned to a different CPU (total 16 cores here). Each
> > > > > > thread is going to monitor its own overflow (i.e. receive its own
> > > > > > overflow notification). For configuring this, do i need to set
> > > > > > PFM_FL_SYSTEM_WIDE while creating PFM_CONTEXT ?
> > > > >
> > > > > In system-wide perfmon requires that you create as many contexts
> > > > > and you have CPU core to monitor. That each context is loaded onto
> > > > > the right CPU core via pfm_load_context(). On IA-64 currently, you
> > > > > are using the v2.0 interface which has the PFM_LOAD_CONTEXT
> > > > > command. On this version, perfmon will pick the CPU used to mke the
> > > > > PFM_LOAD_CONTEXT call as the CPU to monitor. This means you need to
> > > > > ensure that you have pinned the caller thread to the right CPU core
> > > > > prior to making the call. Each context needs to be created with the
> > > > > PFM_FL_SYSTEM_WIDE flag set.
> > > >
> > > > Setting the PFM_FL_SYSTEM_WIDE flag at the context creation time
> > > > gives me the following error at the time I write to PMCs.
> > > > PFM_WRITE_PMCS:: Invalid argument
> > > > perfmonctl error PFM_WRITE_PMCS errno 22
> > > >
> > > > The flags I am passing with PFM_WRITE_PMCS are :
> > > > /*
> > > > * indicate we want notification when buffer is full
> > > > */
> > > > pc[0].reg_flags |= PFM_REGFL_OVFL_NOTIFY;
> > > > /*
> > > > * indicate which PMD to include in the sample
> > > > */
> > > > pc[0].reg_smpl_pmds[0] = DEAR_REGS_MASK;
> > > >
> > > > This code works if I remove PFM_FL_SYSTEM_WIDE flag at the time of
> > > > context creation.
> > >
> > > Oh, I think for this kernel version, there was an explicit check for
> > > the PMC.pm bit when running in system wide. You need to use the libpfm
> > > PFMLIB_PFP_SYSTEMWIDE on the pfmlib_input_param_t.pfp_flags of
> > > pfm_dispatch_events().
> > >
> > > This restriction has been removed for current versions, the kernel
> > > automatically forces the PMC.pm bit for system-wide contexts.
> > >
> > > --
> >
> > My code compiles fine and runs without error using the above method. But
> > I don't see any overflow signals now. I was trying to look for some
> > similar examples in libpfm.
> > syst.c is one but it doesn't use threads and just pins the process on a
> > random cpu. It also doesn't have any signal handling mechanism. Can you
> > point me to some example code which does what I want ?
> >
> > > -Stephane.
> >
> > -Vivek
/*
* notify_self2.c - example of how you can use overflow notifications with F_SETSIG
*
* Copyright (c) 2002-2006 Hewlett-Packard Development Company, L.P.
* Contributed by Stephane Eranian <[EMAIL PROTECTED]>
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
* of the Software, and to permit persons to whom the Software is furnished to do so,
* subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
* INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
* PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
* HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
* CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE
* OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*
* This file is part of libpfm, a performance monitoring support library for
* applications on Linux/ia64.
*/
#include <sys/types.h>
#include <inttypes.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <errno.h>
#include <unistd.h>
#include <string.h>
#include <signal.h>
#include <fcntl.h>
#include <sched.h>
#include <perfmon/perfmon.h>
#include <perfmon/pfmlib.h>
#define SMPL_PERIOD 1000000000UL
static volatile unsigned long notification_received;
#define NUM_PMCS PFMLIB_MAX_PMCS
#define NUM_PMDS PFMLIB_MAX_PMDS
static pfarg_reg_t pd[NUM_PMDS];
static int ctx_fd;
static char *event1_name;
static void fatal_error(char *fmt,...) __attribute__((noreturn));
static void
fatal_error(char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
vfprintf(stderr, fmt, ap);
va_end(ap);
exit(1);
}
static void
sigio_handler(int n, struct siginfo *info, struct sigcontext *sc)
{
pfm_msg_t msg;
int fd = info->si_fd;
int r;
printf("In sigio handler \n");
if (fd != ctx_fd) {
fatal_error("handler does not get valid file descriptor\n");
}
if (perfmonctl(fd, PFM_READ_PMDS, pd+1, 1) == -1) {
fatal_error("PFM_READ_PMDS: %s", strerror(errno));
}
r = read(fd, &msg, sizeof(msg));
if (r != sizeof(msg)) {
fatal_error("cannot read overflow message: %s\n", strerror(errno));
}
if (msg.type != PFM_MSG_OVFL) {
fatal_error("unexpected msg type: %d\n",msg.type);
}
/*
* XXX: risky to do printf() in signal handler!
*/
if (event1_name)
printf("Notification %lu: %"PRIu64" %s\n", notification_received, pd[1].reg_value, event1_name);
else
printf("Notification %lu\n", notification_received);
/*
* At this point, the counter used for the sampling period has already
* be reset by the kernel because we are in non-blocking mode, self-monitoring.
*/
/*
* increment our notification counter
*/
notification_received++;
/*
* And resume monitoring
*/
if (perfmonctl(fd, PFM_RESTART,NULL, 0) == -1) {
fatal_error("PFM_RESTART: %s", strerror(errno));
}
}
/*
* infinite loop waiting for notification to get out
*/
void
busyloop(void)
{
/*
* busy loop to burn CPU cycles
*/
for(;notification_received < 3;) ;
}
int
main(int argc, char **argv)
{
pfarg_context_t ctx[1];
pfmlib_input_param_t inp;
pfmlib_output_param_t outp;
pfarg_reg_t pc[NUM_PMCS];
pfarg_load_t load_args;
pfmlib_options_t pfmlib_options;
cpu_set_t new_mask ;
struct sigaction act;
unsigned int i, num_counters;
size_t len;
int ret;
// VT_
__CPU_ZERO(&new_mask);
__CPU_SET(1,&new_mask);
ret=sched_setaffinity(getpid(),sizeof(new_mask),&new_mask);
if(ret != 0)
{
fprintf(stderr,"sched_SETaffinity failed. perror reports :");
perror("PERROR:");
}
else
printf(" Process bound \n");
/*
* Initialize pfm library (required before we can use it)
*/
if (pfm_initialize() != PFMLIB_SUCCESS) {
printf("Can't initialize library\n");
exit(1);
}
/*
* Install the signal handler (SIGIO)
*/
memset(&act, 0, sizeof(act));
act.sa_handler = (sig_t)sigio_handler;
sigaction (SIGIO, &act, 0);
/*
* pass options to library (optional)
*/
memset(&pfmlib_options, 0, sizeof(pfmlib_options));
pfmlib_options.pfm_debug = 0; /* set to 1 for debug */
pfm_set_options(&pfmlib_options);
memset(pc, 0, sizeof(pc));
memset(ctx, 0, sizeof(ctx));
memset(&load_args, 0, sizeof(load_args));
memset(&inp,0, sizeof(inp));
memset(&outp,0, sizeof(outp));
pfm_get_num_counters(&num_counters);
if (pfm_get_cycle_event(&inp.pfp_events[0]) != PFMLIB_SUCCESS)
fatal_error("cannot find cycle event\n");
if (pfm_get_inst_retired_event(&inp.pfp_events[1]) != PFMLIB_SUCCESS)
fatal_error("cannot find inst retired event\n");
i = 2;
/*
* set the default privilege mode for all counters:
* PFM_PLM3 : user level only
*/
inp.pfp_dfl_plm = PFM_PLM3;
if (i > num_counters) {
i = num_counters;
printf("too many events provided (max=%d events), using first %d event(s)\n", num_counters, i);
}
/*
* how many counters we use
*/
inp.pfp_event_count = i;
if (i > 1) {
pfm_get_max_event_name_len(&len);
event1_name = malloc(len+1);
if (event1_name == NULL)
fatal_error("cannot allocate event name\n");
pfm_get_full_event_name(&inp.pfp_events[1], event1_name, len+1);
}
// VT_
inp.pfp_flags = PFMLIB_PFP_SYSTEMWIDE;
/*
* let the library figure out the values for the PMCS
*/
if ((ret=pfm_dispatch_events(&inp, NULL, &outp, NULL)) != PFMLIB_SUCCESS) {
fatal_error("Cannot configure events: %s\n", pfm_strerror(ret));
}
// VT_
ctx[0].ctx_flags |= PFM_FL_SYSTEM_WIDE ;
/*
* now create the context for self monitoring/per-task
*/
if (perfmonctl(0, PFM_CREATE_CONTEXT, ctx, 1) == -1 ) {
if (errno == ENOSYS) {
fatal_error("Your kernel does not have performance monitoring support!\n");
}
fatal_error("Can't create PFM context %s\n", strerror(errno));
}
ctx_fd = ctx->ctx_fd;
/*
* Now prepare the argument to initialize the PMDs and PMCS.
* We use pfp_pmc_count to determine the number of registers to
* setup. Note that this field can be >= pfp_event_count.
*/
for (i=0; i < outp.pfp_pmc_count; i++) {
pc[i].reg_num = outp.pfp_pmcs[i].reg_num;
pc[i].reg_value = outp.pfp_pmcs[i].reg_value;
}
for (i=0; i < inp.pfp_event_count; i++) {
pd[i].reg_num = pc[i].reg_num;
}
/*
* We want to get notified when the counter used for our first
* event overflows
*/
pc[0].reg_flags |= PFM_REGFL_OVFL_NOTIFY;
pc[0].reg_reset_pmds[0] |= 1UL << outp.pfp_pmcs[1].reg_num;
/*
* we arm the first counter, such that it will overflow
* after SMPL_PERIOD events have been observed
*/
pd[0].reg_value = (~0UL) - SMPL_PERIOD + 1;
pd[0].reg_long_reset = (~0UL) - SMPL_PERIOD + 1;
pd[0].reg_short_reset = (~0UL) - SMPL_PERIOD + 1;
/*
* Now program the registers
*
* We don't use the save variable to indicate the number of elements passed to
* the kernel because, as we said earlier, pc may contain more elements than
* the number of events we specified, i.e., contains more than counting monitors.
*/
if (perfmonctl(ctx_fd, PFM_WRITE_PMCS, pc, outp.pfp_pmc_count) == -1) {
fatal_error("perfmonctl error PFM_WRITE_PMCS errno %d\n",errno);
}
if (perfmonctl(ctx_fd, PFM_WRITE_PMDS, pd, inp.pfp_event_count) == -1) {
fatal_error("perfmonctl error PFM_WRITE_PMDS errno %d\n",errno);
}
/*
* we want to monitor ourself
*/
load_args.load_pid = getpid();
if (perfmonctl(ctx_fd, PFM_LOAD_CONTEXT, &load_args, 1) == -1) {
fatal_error("perfmonctl error PFM_WRITE_PMDS errno %d\n",errno);
}
/*
* setup asynchronous notification on the file descriptor
*/
ret = fcntl(ctx_fd, F_SETFL, fcntl(ctx_fd, F_GETFL, 0) | O_ASYNC);
if (ret == -1) {
fatal_error("cannot set ASYNC: %s\n", strerror(errno));
}
/*
* get ownership of the descriptor
*/
ret = fcntl(ctx_fd, F_SETOWN, getpid());
if (ret == -1) {
fatal_error("cannot setown: %s\n", strerror(errno));
}
#ifndef _GNU_SOURCE
#error "this program must be compiled with -D_GNU_SOURCE"
#else
/*
* when you explicitely declare that you want a particular signal,
* even with you use the default signal, the kernel will send more
* information concerning the event to the signal handler.
*
* In particular, it will send the file descriptor from which the
* event is originating which can be quite useful when monitoring
* multiple tasks from a single thread.
*/
ret = fcntl(ctx_fd, F_SETSIG, SIGIO);
if (ret == -1) {
fatal_error("cannot setsig: %s\n", strerror(errno));
}
#endif
/*
* Let's roll now
*/
pfm_self_start(ctx_fd);
busyloop();
pfm_self_stop(ctx_fd);
/*
* free our context
*/
close(ctx_fd);
return 0;
}
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