/* * ita2_opcode.c - example of how to use the opcode matcher with the Itanium2 PMU * * Copyright (c) 2002-2006 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/ia64. */ #include #include #include #include #include #include #include #include #include #include #define NUM_PMCS PFMLIB_MAX_PMCS #define NUM_PMDS PFMLIB_MAX_PMDS #define MAX_EVT_NAME_LEN 128 #define MAX_PMU_NAME_LEN 32 /* * we don't use static to make sure the compiler does not inline the function */ int do_test(unsigned long loop) { unsigned long sum = 0; while(loop--) sum += loop; return sum; } 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); } int main(void) { pfmlib_input_param_t inp; pfmlib_output_param_t outp; pfmlib_ita2_input_param_t ita2_inp; pfarg_reg_t pd[NUM_PMDS]; pfarg_reg_t pc[NUM_PMCS]; pfarg_context_t ctx[1]; pfarg_load_t load_args; pfmlib_options_t pfmlib_options; int ret; int type = 0; int id; unsigned int i; char name[MAX_EVT_NAME_LEN]; /* * Initialize pfm library (required before we can use it) */ if (pfm_initialize() != PFMLIB_SUCCESS) { fatal_error("Can't initialize library\n"); } /* * Let's make sure we run this on the right CPU */ pfm_get_pmu_type(&type); if (type != PFMLIB_ITANIUM2_PMU) { char model[MAX_PMU_NAME_LEN]; pfm_get_pmu_name(model, MAX_PMU_NAME_LEN); fatal_error("this program does not work with the %s PMU\n", model); } /* * 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 = 0; /* set to 1 for verbose */ pfm_set_options(&pfmlib_options); memset(pd, 0, sizeof(pd)); 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)); memset(&ita2_inp,0, sizeof(ita2_inp)); /* * We indicate that we are using the PMC8 opcode matcher. This is required * otherwise the library add PMC8 to the list of PMC to pogram during * pfm_dispatch_events(). */ ita2_inp.pfp_ita2_pmc8.opcm_used = 1; /* * We want to match all the br.cloop in our test function. * This branch is an IP-relative branch for which the major * opcode (bits [40-37]=4) and the btype field is 5 (which represents * bits[6-8]) so it is included in the match/mask fields of PMC8. * It is necessarily in a B slot. * * We don't care which operands are used with br.cloop therefore * the mask field of pmc8 is set such that only the 4 bits of the * opcode and 3 bits of btype must match exactly. This is accomplished by * clearing the top 4 bits and bits [6-8] of the mask field and setting the * remaining bits. Similarly, the match field only has the opcode value and btype * set according to the encoding of br.cloop, the * remaining bits are zero. Bit 60 of PMC8 is set to indicate * that we look only in B slots (this is the only possibility for * this instruction anyway). * * So the binary representation of the value for PMC8 is as follows: * * 6666555555555544444444443333333333222222222211111111110000000000 * 3210987654321098765432109876543210987654321098765432109876543210 * ---------------------------------------------------------------- * 0001010000000000000000101000000000000011111111111111000111111000 * * which yields a value of 0x1400028003fff1f8. * * Depending on the level of optimization to compile this code, it may * be that the count reported could be zero, if the compiler uses a br.cond * instead of br.cloop. * * * The 0x1 sets the ig_ad field to make sure we ignore any range restriction. * Also bit 2 must always be set */ ita2_inp.pfp_ita2_pmc8.pmc_val = 0x1400028003fff1fa; /* * 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_find_full_event("IA64_TAGGED_INST_RETIRED_IBRP0_PMC8", &inp.pfp_events[0]) != PFMLIB_SUCCESS) { fatal_error("cannot find event IA64_TAGGED_INST_RETIRED_IBRP0_PMC8\n"); } /* * set the privilege mode: * PFM_PLM3 : user level only */ inp.pfp_dfl_plm = PFM_PLM3; /* * how many counters we use */ inp.pfp_event_count = 1; /* * let the library figure out the values for the PMCS */ if ((ret=pfm_dispatch_events(&inp, &ita2_inp, &outp, NULL)) != PFMLIB_SUCCESS) { fatal_error("cannot configure events: %s\n", pfm_strerror(ret)); } /* * 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)); } /* * extract the unique identifier for our context, a regular file descriptor */ id = ctx[0].ctx_fd; /* * 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; } /* * the PMC controlling the event ALWAYS come first, that's why this loop * is safe even when extra PMC are needed to support a particular event. */ for (i=0; i < inp.pfp_event_count; i++) { pd[i].reg_num = pc[i].reg_num; } printf("event_count=%d id=%d\n", inp.pfp_event_count, id); /* * 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 (perfmonctl(id, PFM_WRITE_PMCS, pc, outp.pfp_pmc_count) == -1) { fatal_error("perfmonctl error PFM_WRITE_PMCS errno %d\n",errno); } if (perfmonctl(id, PFM_WRITE_PMDS, pd, inp.pfp_event_count) == -1) { fatal_error("perfmonctl error PFM_WRITE_PMDS errno %d\n",errno); } /* * now we load (i.e., attach) the context to ourself */ load_args.load_pid = getpid(); if (perfmonctl(id, PFM_LOAD_CONTEXT, &load_args, 1) == -1) { fatal_error("perfmonctl error PFM_LOAD_CONTEXT errno %d\n",errno); } /* * Let's roll now. */ pfm_self_start(id); do_test(100UL); pfm_self_stop(id); /* * now read the results */ if (perfmonctl(id, PFM_READ_PMDS, pd, inp.pfp_event_count) == -1) { fatal_error("perfmonctl error READ_PMDS errno %d\n",errno); } /* * print the results */ pfm_get_full_event_name(&inp.pfp_events[0], name, MAX_EVT_NAME_LEN); printf("PMD%u %20lu %s\n", pd[0].reg_num, pd[0].reg_value, name); if (pd[0].reg_value != 0) printf("compiler used br.cloop\n"); else printf("compiler did not use br.cloop\n"); /* * let's stop this now */ close(id); return 0; }