/* * self_smpl.c - example of self sampling using a kernel samplig buffer * * Copyright (c) 2009 Google, Inc * Contributed by Stephane Eranian * * Based on mont_dear.c from: * Copyright (c) 2005-2006 Hewlett-Packard Development Company, L.P. * Contributed by Stephane Eranian * * 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. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define SMPL_PERIOD (2400000) typedef pfm_dfl_smpl_hdr_t smpl_hdr_t; typedef pfm_dfl_smpl_entry_t smpl_entry_t; typedef pfm_dfl_smpl_arg_t smpl_arg_t; static int fd; static void *smpl_vaddr; static size_t entry_size; long do_test(unsigned long size) { unsigned long i, sum = 0; int *array; array = (int *)malloc(size * sizeof(int)); if (array == NULL ) { printf("line = %d No memory available!\n", __LINE__); exit(1); } for(i=0; ihdr_overflows <= last_ovfl && last_ovfl != ~0UL) { printf("skipping identical set of samples %"PRIu64" <= %"PRIu64"\n", hdr->hdr_overflows, last_ovfl); return; } pos = (unsigned long)(hdr+1); count = hdr->hdr_count; /* * walk through all the entries recored in the buffer */ while(count--) { ent = (smpl_entry_t *)pos; /* * print entry header */ printf("Entry %"PRIu64" PID:%d TID:%d CPU:%d STAMP:0x%"PRIx64" IIP:0x%016"PRIx64"\n", smpl_entry++, ent->tgid, ent->pid, ent->cpu, ent->tstamp, ent->ip); /* * move to next entry */ pos += entry_size; } } static void overflow_handler(int n, struct siginfo *info, struct sigcontext *sc) { process_smpl_buffer(); /* * And resume monitoring */ if (pfm_restart(fd)) errx(1, "pfm_restart"); } int main(void) { pfarg_pmd_t pd[8]; pfarg_pmc_t pc[8]; pfmlib_input_param_t inp; pfmlib_output_param_t outp; pfarg_ctx_t ctx; pfarg_load_t load_args; smpl_arg_t buf_arg; pfmlib_options_t pfmlib_options; unsigned long nloop = 10000; struct sigaction act; unsigned int i; int ret; /* * Initialize pfm library (required before we can use it) */ if (pfm_initialize() != PFMLIB_SUCCESS) errx(1, "cannot initialize library\n"); /* * Install the overflow handler (SIGIO) */ memset(&act, 0, sizeof(act)); act.sa_handler = (sig_t)overflow_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 */ pfmlib_options.pfm_verbose = 1; /* set to 1 for debug */ pfm_set_options(&pfmlib_options); memset(pd, 0, sizeof(pd)); memset(pc, 0, sizeof(pc)); memset(pc, 0, sizeof(pc)); memset(&ctx, 0, sizeof(ctx)); memset(&buf_arg, 0, sizeof(buf_arg)); memset(&load_args, 0, sizeof(load_args)); /* * prepare parameters to library. we don't use any Itanium * specific features here. so the pfp_model is NULL. */ memset(&inp,0, sizeof(inp)); memset(&outp,0, sizeof(outp)); /* * To count the number of occurence of this instruction, we must * program a counting monitor with the IA64_TAGGED_INST_RETIRED_PMC8 * event. */ if (pfm_get_cycle_event(&inp.pfp_events[0]) != PFMLIB_SUCCESS) errx(1, "cannot find cycle event\n"); /* * set the (global) privilege mode: * PFM_PLM0 : kernel level only */ inp.pfp_dfl_plm = PFM_PLM3|PFM_PLM0; /* * how many counters we use */ inp.pfp_event_count = 1; /* * let the library figure out the values for the PMCS * * We use all global settings for this EAR. */ if ((ret=pfm_dispatch_events(&inp, NULL, &outp, NULL)) != PFMLIB_SUCCESS) errx(1, "cannot configure events: %s\n", pfm_strerror(ret)); /* * the size of the buffer is indicated in bytes (not entries). * * The kernel will record into the buffer up to a certain point. * No partial samples are ever recorded. */ buf_arg.buf_size = getpagesize(); /* * do not generate overflow notification messages */ ctx.ctx_flags = PFM_FL_OVFL_NO_MSG; /* * now create the context for self monitoring/per-task */ fd = pfm_create_context(&ctx, PFM_DFL_SMPL_NAME, &buf_arg, sizeof(buf_arg)); if (fd == -1) { if (errno == ENOSYS) errx(1, "kernel does not have performance monitoring support!\n"); errx(1, "cannot create PFM context %s\n", strerror(errno)); } /* * retrieve the virtual address at which the sampling * buffer has been mapped */ smpl_vaddr = mmap(NULL, (size_t)buf_arg.buf_size, PROT_READ, MAP_PRIVATE, fd, 0); if (smpl_vaddr == MAP_FAILED) errx(1, "cannot mmap sampling buffer errno %d\n", errno); printf("Sampling buffer mapped at %p\n", smpl_vaddr); /* * Now prepare the argument to initialize the PMDs and PMCS. * We must pfp_pmc_count to determine the number of PMC to intialize. * We must use pfp_event_count to determine the number of PMD to initialize. * Some events causes extra PMCs to be used, so pfp_pmc_count may be >= pfp_event_count. * * This step is new compared to libpfm-2.x. It is necessary because the library no * longer knows about the kernel data structures. */ 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; } /* * figure out pmd mapping from output pmc */ for (i=0; i < outp.pfp_pmd_count; i++) pd[i].reg_num = outp.pfp_pmds[i].reg_num; /* * indicate we want notification when buffer is full */ pd[0].reg_flags |= PFM_REGFL_OVFL_NOTIFY; entry_size = sizeof(smpl_entry_t); /* * initialize the PMD and the sampling period */ pd[0].reg_value = - SMPL_PERIOD; pd[0].reg_long_reset = - SMPL_PERIOD; pd[0].reg_short_reset = - SMPL_PERIOD; /* * 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 thann coutning monitors. */ if (pfm_write_pmcs(fd, pc, outp.pfp_pmc_count)) errx(1, "pfm_write_pmcs error errno %d\n",errno); if (pfm_write_pmds(fd, pd, outp.pfp_pmd_count)) errx(1, "pfm_write_pmds error errno %d\n",errno); /* * attach context to stopped task */ load_args.load_pid = getpid(); if (pfm_load_context(fd, &load_args)) errx(1, "pfm_load_context error errno %d\n",errno); /* * setup asynchronous notification on the file descriptor */ ret = fcntl(fd, F_SETFL, fcntl(fd, F_GETFL, 0) | O_ASYNC); if (ret == -1) errx(1, "cannot set ASYNC: %s\n", strerror(errno)); /* * get ownership of the descriptor */ ret = fcntl(fd, F_SETOWN, getpid()); if (ret == -1) errx(1, "cannot setown: %s\n", strerror(errno)); /* * Let's roll now. */ ret = pfm_start(fd, NULL); if (ret == -1) errx(1, "cannot pfm_start: %s\n", strerror(errno)); while(nloop--) do_test(100000); ret = pfm_stop(fd); if (ret == -1) errx(1, "cannot pfm_stop: %s\n", strerror(errno)); /* * We must call the processing routine to cover the last entries recorded * in the sampling buffer, i.e. which may not be full */ process_smpl_buffer(); /* * let's stop this now */ munmap(smpl_vaddr, (size_t)buf_arg.buf_size); close(fd); return 0; }