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/*
* Copyright (C) 2019 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#define LOG_TAG "libtimeinstate"
#include "cputimeinstate.h"
#include <bpf_timeinstate.h>
#include <dirent.h>
#include <errno.h>
#include <inttypes.h>
#include <sys/sysinfo.h>
#include <mutex>
#include <numeric>
#include <optional>
#include <set>
#include <string>
#include <unordered_map>
#include <vector>
#include <android-base/file.h>
#include <android-base/parseint.h>
#include <android-base/stringprintf.h>
#include <android-base/strings.h>
#include <android-base/unique_fd.h>
#include <bpf/BpfMap.h>
#include <libbpf.h>
#include <log/log.h>
using android::base::StringPrintf;
using android::base::unique_fd;
namespace android {
namespace bpf {
static std::mutex gInitializedMutex;
static bool gInitialized = false;
static std::mutex gTrackingMutex;
static bool gTracking = false;
static uint32_t gNPolicies = 0;
static uint32_t gNCpus = 0;
static std::vector<std::vector<uint32_t>> gPolicyFreqs;
static std::vector<std::vector<uint32_t>> gPolicyCpus;
static std::set<uint32_t> gAllFreqs;
static unique_fd gTisMapFd;
static unique_fd gConcurrentMapFd;
static unique_fd gUidLastUpdateMapFd;
static std::optional<std::vector<uint32_t>> readNumbersFromFile(const std::string &path) {
std::string data;
if (!android::base::ReadFileToString(path, &data)) return {};
auto strings = android::base::Split(data, " \n");
std::vector<uint32_t> ret;
for (const auto &s : strings) {
if (s.empty()) continue;
uint32_t n;
if (!android::base::ParseUint(s, &n)) return {};
ret.emplace_back(n);
}
return ret;
}
static int isPolicyFile(const struct dirent *d) {
return android::base::StartsWith(d->d_name, "policy");
}
static int comparePolicyFiles(const struct dirent **d1, const struct dirent **d2) {
uint32_t policyN1, policyN2;
if (sscanf((*d1)->d_name, "policy%" SCNu32 "", &policyN1) != 1 ||
sscanf((*d2)->d_name, "policy%" SCNu32 "", &policyN2) != 1)
return 0;
return policyN1 - policyN2;
}
static bool initGlobals() {
std::lock_guard<std::mutex> guard(gInitializedMutex);
if (gInitialized) return true;
gNCpus = get_nprocs_conf();
struct dirent **dirlist;
const char basepath[] = "/sys/devices/system/cpu/cpufreq";
int ret = scandir(basepath, &dirlist, isPolicyFile, comparePolicyFiles);
if (ret == -1) return false;
gNPolicies = ret;
std::vector<std::string> policyFileNames;
for (uint32_t i = 0; i < gNPolicies; ++i) {
policyFileNames.emplace_back(dirlist[i]->d_name);
free(dirlist[i]);
}
free(dirlist);
for (const auto &policy : policyFileNames) {
std::vector<uint32_t> freqs;
for (const auto &name : {"available", "boost"}) {
std::string path =
StringPrintf("%s/%s/scaling_%s_frequencies", basepath, policy.c_str(), name);
auto nums = readNumbersFromFile(path);
if (!nums) continue;
freqs.insert(freqs.end(), nums->begin(), nums->end());
}
if (freqs.empty()) return false;
std::sort(freqs.begin(), freqs.end());
gPolicyFreqs.emplace_back(freqs);
for (auto freq : freqs) gAllFreqs.insert(freq);
std::string path = StringPrintf("%s/%s/%s", basepath, policy.c_str(), "related_cpus");
auto cpus = readNumbersFromFile(path);
if (!cpus) return false;
gPolicyCpus.emplace_back(*cpus);
}
gTisMapFd = unique_fd{bpf_obj_get(BPF_FS_PATH "map_time_in_state_uid_time_in_state_map")};
if (gTisMapFd < 0) return false;
gConcurrentMapFd =
unique_fd{bpf_obj_get(BPF_FS_PATH "map_time_in_state_uid_concurrent_times_map")};
if (gConcurrentMapFd < 0) return false;
gUidLastUpdateMapFd =
unique_fd{bpf_obj_get(BPF_FS_PATH "map_time_in_state_uid_last_update_map")};
if (gUidLastUpdateMapFd < 0) return false;
gInitialized = true;
return true;
}
static bool attachTracepointProgram(const std::string &eventType, const std::string &eventName) {
std::string path = StringPrintf(BPF_FS_PATH "prog_time_in_state_tracepoint_%s_%s",
eventType.c_str(), eventName.c_str());
int prog_fd = retrieveProgram(path.c_str());
if (prog_fd < 0) return false;
return bpf_attach_tracepoint(prog_fd, eventType.c_str(), eventName.c_str()) >= 0;
}
static std::optional<uint32_t> getPolicyFreqIdx(uint32_t policy) {
auto path = StringPrintf("/sys/devices/system/cpu/cpufreq/policy%u/scaling_cur_freq",
gPolicyCpus[policy][0]);
auto freqVec = readNumbersFromFile(path);
if (!freqVec.has_value() || freqVec->size() != 1) return {};
for (uint32_t idx = 0; idx < gPolicyFreqs[policy].size(); ++idx) {
if ((*freqVec)[0] == gPolicyFreqs[policy][idx]) return idx + 1;
}
return {};
}
// Start tracking and aggregating data to be reported by getUidCpuFreqTimes and getUidsCpuFreqTimes.
// Returns true on success, false otherwise.
// Tracking is active only once a live process has successfully called this function; if the calling
// process dies then it must be called again to resume tracking.
// This function should *not* be called while tracking is already active; doing so is unnecessary
// and can lead to accounting errors.
bool startTrackingUidTimes() {
std::lock_guard<std::mutex> guard(gTrackingMutex);
if (!initGlobals()) return false;
if (gTracking) return true;
unique_fd cpuPolicyFd(mapRetrieveWO(BPF_FS_PATH "map_time_in_state_cpu_policy_map"));
if (cpuPolicyFd < 0) return false;
for (uint32_t i = 0; i < gPolicyCpus.size(); ++i) {
for (auto &cpu : gPolicyCpus[i]) {
if (writeToMapEntry(cpuPolicyFd, &cpu, &i, BPF_ANY)) return false;
}
}
unique_fd freqToIdxFd(mapRetrieveWO(BPF_FS_PATH "map_time_in_state_freq_to_idx_map"));
if (freqToIdxFd < 0) return false;
freq_idx_key_t key;
for (uint32_t i = 0; i < gNPolicies; ++i) {
key.policy = i;
for (uint32_t j = 0; j < gPolicyFreqs[i].size(); ++j) {
key.freq = gPolicyFreqs[i][j];
// Start indexes at 1 so that uninitialized state is distinguishable from lowest freq.
// The uid_times map still uses 0-based indexes, and the sched_switch program handles
// conversion between them, so this does not affect our map reading code.
uint32_t idx = j + 1;
if (writeToMapEntry(freqToIdxFd, &key, &idx, BPF_ANY)) return false;
}
}
unique_fd cpuLastUpdateFd(mapRetrieveWO(BPF_FS_PATH "map_time_in_state_cpu_last_update_map"));
if (cpuLastUpdateFd < 0) return false;
std::vector<uint64_t> zeros(get_nprocs_conf(), 0);
uint32_t zero = 0;
if (writeToMapEntry(cpuLastUpdateFd, &zero, zeros.data(), BPF_ANY)) return false;
unique_fd nrActiveFd(mapRetrieveWO(BPF_FS_PATH "map_time_in_state_nr_active_map"));
if (nrActiveFd < 0) return false;
if (writeToMapEntry(nrActiveFd, &zero, &zero, BPF_ANY)) return false;
unique_fd policyNrActiveFd(mapRetrieveWO(BPF_FS_PATH "map_time_in_state_policy_nr_active_map"));
if (policyNrActiveFd < 0) return false;
for (uint32_t i = 0; i < gNPolicies; ++i) {
if (writeToMapEntry(policyNrActiveFd, &i, &zero, BPF_ANY)) return false;
}
unique_fd policyFreqIdxFd(mapRetrieveWO(BPF_FS_PATH "map_time_in_state_policy_freq_idx_map"));
if (policyFreqIdxFd < 0) return false;
for (uint32_t i = 0; i < gNPolicies; ++i) {
auto freqIdx = getPolicyFreqIdx(i);
if (!freqIdx.has_value()) return false;
if (writeToMapEntry(policyFreqIdxFd, &i, &(*freqIdx), BPF_ANY)) return false;
}
gTracking = attachTracepointProgram("sched", "sched_switch") &&
attachTracepointProgram("power", "cpu_frequency");
return gTracking;
}
std::optional<std::vector<std::vector<uint32_t>>> getCpuFreqs() {
if (!gInitialized && !initGlobals()) return {};
return gPolicyFreqs;
}
// Retrieve the times in ns that uid spent running at each CPU frequency.
// Return contains no value on error, otherwise it contains a vector of vectors using the format:
// [[t0_0, t0_1, ...],
// [t1_0, t1_1, ...], ...]
// where ti_j is the ns that uid spent running on the ith cluster at that cluster's jth lowest freq.
std::optional<std::vector<std::vector<uint64_t>>> getUidCpuFreqTimes(uint32_t uid) {
if (!gInitialized && !initGlobals()) return {};
std::vector<std::vector<uint64_t>> out;
uint32_t maxFreqCount = 0;
for (const auto &freqList : gPolicyFreqs) {
if (freqList.size() > maxFreqCount) maxFreqCount = freqList.size();
out.emplace_back(freqList.size(), 0);
}
std::vector<tis_val_t> vals(gNCpus);
time_key_t key = {.uid = uid};
for (uint32_t i = 0; i <= (maxFreqCount - 1) / FREQS_PER_ENTRY; ++i) {
key.bucket = i;
if (findMapEntry(gTisMapFd, &key, vals.data())) {
if (errno != ENOENT) return {};
continue;
}
auto offset = i * FREQS_PER_ENTRY;
auto nextOffset = (i + 1) * FREQS_PER_ENTRY;
for (uint32_t j = 0; j < gNPolicies; ++j) {
if (offset >= gPolicyFreqs[j].size()) continue;
auto begin = out[j].begin() + offset;
auto end = nextOffset < gPolicyFreqs[j].size() ? begin + FREQS_PER_ENTRY : out[j].end();
for (const auto &cpu : gPolicyCpus[j]) {
std::transform(begin, end, std::begin(vals[cpu].ar), begin, std::plus<uint64_t>());
}
}
}
return out;
}
static std::optional<bool> uidUpdatedSince(uint32_t uid, uint64_t lastUpdate,
uint64_t *newLastUpdate) {
uint64_t uidLastUpdate;
if (findMapEntry(gUidLastUpdateMapFd, &uid, &uidLastUpdate)) return {};
// Updates that occurred during the previous read may have been missed. To mitigate
// this, don't ignore entries updated up to 1s before *lastUpdate
constexpr uint64_t NSEC_PER_SEC = 1000000000;
if (uidLastUpdate + NSEC_PER_SEC < lastUpdate) return false;
if (uidLastUpdate > *newLastUpdate) *newLastUpdate = uidLastUpdate;
return true;
}
// Retrieve the times in ns that each uid spent running at each CPU freq.
// Return contains no value on error, otherwise it contains a map from uids to vectors of vectors
// using the format:
// { uid0 -> [[t0_0_0, t0_0_1, ...], [t0_1_0, t0_1_1, ...], ...],
// uid1 -> [[t1_0_0, t1_0_1, ...], [t1_1_0, t1_1_1, ...], ...], ... }
// where ti_j_k is the ns uid i spent running on the jth cluster at the cluster's kth lowest freq.
std::optional<std::unordered_map<uint32_t, std::vector<std::vector<uint64_t>>>>
getUidsCpuFreqTimes() {
return getUidsUpdatedCpuFreqTimes(nullptr);
}
// Retrieve the times in ns that each uid spent running at each CPU freq, excluding UIDs that have
// not run since before lastUpdate.
// Return format is the same as getUidsCpuFreqTimes()
std::optional<std::unordered_map<uint32_t, std::vector<std::vector<uint64_t>>>>
getUidsUpdatedCpuFreqTimes(uint64_t *lastUpdate) {
if (!gInitialized && !initGlobals()) return {};
time_key_t key, prevKey;
std::unordered_map<uint32_t, std::vector<std::vector<uint64_t>>> map;
if (getFirstMapKey(gTisMapFd, &key)) {
if (errno == ENOENT) return map;
return std::nullopt;
}
std::vector<std::vector<uint64_t>> mapFormat;
for (const auto &freqList : gPolicyFreqs) mapFormat.emplace_back(freqList.size(), 0);
uint64_t newLastUpdate = lastUpdate ? *lastUpdate : 0;
std::vector<tis_val_t> vals(gNCpus);
do {
if (lastUpdate) {
auto uidUpdated = uidUpdatedSince(key.uid, *lastUpdate, &newLastUpdate);
if (!uidUpdated.has_value()) return {};
if (!*uidUpdated) continue;
}
if (findMapEntry(gTisMapFd, &key, vals.data())) return {};
if (map.find(key.uid) == map.end()) map.emplace(key.uid, mapFormat);
auto offset = key.bucket * FREQS_PER_ENTRY;
auto nextOffset = (key.bucket + 1) * FREQS_PER_ENTRY;
for (uint32_t i = 0; i < gNPolicies; ++i) {
if (offset >= gPolicyFreqs[i].size()) continue;
auto begin = map[key.uid][i].begin() + offset;
auto end = nextOffset < gPolicyFreqs[i].size() ? begin + FREQS_PER_ENTRY :
map[key.uid][i].end();
for (const auto &cpu : gPolicyCpus[i]) {
std::transform(begin, end, std::begin(vals[cpu].ar), begin, std::plus<uint64_t>());
}
}
prevKey = key;
} while (prevKey = key, !getNextMapKey(gTisMapFd, &prevKey, &key));
if (errno != ENOENT) return {};
if (lastUpdate && newLastUpdate > *lastUpdate) *lastUpdate = newLastUpdate;
return map;
}
static bool verifyConcurrentTimes(const concurrent_time_t &ct) {
uint64_t activeSum = std::accumulate(ct.active.begin(), ct.active.end(), (uint64_t)0);
uint64_t policySum = 0;
for (const auto &vec : ct.policy) {
policySum += std::accumulate(vec.begin(), vec.end(), (uint64_t)0);
}
return activeSum == policySum;
}
// Retrieve the times in ns that uid spent running concurrently with each possible number of other
// tasks on each cluster (policy times) and overall (active times).
// Return contains no value on error, otherwise it contains a concurrent_time_t with the format:
// {.active = [a0, a1, ...], .policy = [[p0_0, p0_1, ...], [p1_0, p1_1, ...], ...]}
// where ai is the ns spent running concurrently with tasks on i other cpus and pi_j is the ns spent
// running on the ith cluster, concurrently with tasks on j other cpus in the same cluster
std::optional<concurrent_time_t> getUidConcurrentTimes(uint32_t uid, bool retry) {
if (!gInitialized && !initGlobals()) return {};
concurrent_time_t ret = {.active = std::vector<uint64_t>(gNCpus, 0)};
for (const auto &cpuList : gPolicyCpus) ret.policy.emplace_back(cpuList.size(), 0);
std::vector<concurrent_val_t> vals(gNCpus);
time_key_t key = {.uid = uid};
for (key.bucket = 0; key.bucket <= (gNCpus - 1) / CPUS_PER_ENTRY; ++key.bucket) {
if (findMapEntry(gConcurrentMapFd, &key, vals.data())) {
if (errno != ENOENT) return {};
continue;
}
auto offset = key.bucket * CPUS_PER_ENTRY;
auto nextOffset = (key.bucket + 1) * CPUS_PER_ENTRY;
auto activeBegin = ret.active.begin() + offset;
auto activeEnd = nextOffset < gNCpus ? activeBegin + CPUS_PER_ENTRY : ret.active.end();
for (uint32_t cpu = 0; cpu < gNCpus; ++cpu) {
std::transform(activeBegin, activeEnd, std::begin(vals[cpu].active), activeBegin,
std::plus<uint64_t>());
}
for (uint32_t policy = 0; policy < gNPolicies; ++policy) {
if (offset >= gPolicyCpus[policy].size()) continue;
auto policyBegin = ret.policy[policy].begin() + offset;
auto policyEnd = nextOffset < gPolicyCpus[policy].size() ? policyBegin + CPUS_PER_ENTRY
: ret.policy[policy].end();
for (const auto &cpu : gPolicyCpus[policy]) {
std::transform(policyBegin, policyEnd, std::begin(vals[cpu].policy), policyBegin,
std::plus<uint64_t>());
}
}
}
if (!verifyConcurrentTimes(ret) && retry) return getUidConcurrentTimes(uid, false);
return ret;
}
// Retrieve the times in ns that each uid spent running concurrently with each possible number of
// other tasks on each cluster (policy times) and overall (active times).
// Return contains no value on error, otherwise it contains a map from uids to concurrent_time_t's
// using the format:
// { uid0 -> {.active = [a0, a1, ...], .policy = [[p0_0, p0_1, ...], [p1_0, p1_1, ...], ...] }, ...}
// where ai is the ns spent running concurrently with tasks on i other cpus and pi_j is the ns spent
// running on the ith cluster, concurrently with tasks on j other cpus in the same cluster.
std::optional<std::unordered_map<uint32_t, concurrent_time_t>> getUidsConcurrentTimes() {
return getUidsUpdatedConcurrentTimes(nullptr);
}
// Retrieve the times in ns that each uid spent running concurrently with each possible number of
// other tasks on each cluster (policy times) and overall (active times), excluding UIDs that have
// not run since before lastUpdate.
// Return format is the same as getUidsConcurrentTimes()
std::optional<std::unordered_map<uint32_t, concurrent_time_t>> getUidsUpdatedConcurrentTimes(
uint64_t *lastUpdate) {
if (!gInitialized && !initGlobals()) return {};
time_key_t key, prevKey;
std::unordered_map<uint32_t, concurrent_time_t> ret;
if (getFirstMapKey(gConcurrentMapFd, &key)) {
if (errno == ENOENT) return ret;
return {};
}
concurrent_time_t retFormat = {.active = std::vector<uint64_t>(gNCpus, 0)};
for (const auto &cpuList : gPolicyCpus) retFormat.policy.emplace_back(cpuList.size(), 0);
std::vector<concurrent_val_t> vals(gNCpus);
std::vector<uint64_t>::iterator activeBegin, activeEnd, policyBegin, policyEnd;
uint64_t newLastUpdate = lastUpdate ? *lastUpdate : 0;
do {
if (lastUpdate) {
auto uidUpdated = uidUpdatedSince(key.uid, *lastUpdate, &newLastUpdate);
if (!uidUpdated.has_value()) return {};
if (!*uidUpdated) continue;
}
if (findMapEntry(gConcurrentMapFd, &key, vals.data())) return {};
if (ret.find(key.uid) == ret.end()) ret.emplace(key.uid, retFormat);
auto offset = key.bucket * CPUS_PER_ENTRY;
auto nextOffset = (key.bucket + 1) * CPUS_PER_ENTRY;
activeBegin = ret[key.uid].active.begin();
activeEnd = nextOffset < gNCpus ? activeBegin + CPUS_PER_ENTRY : ret[key.uid].active.end();
for (uint32_t cpu = 0; cpu < gNCpus; ++cpu) {
std::transform(activeBegin, activeEnd, std::begin(vals[cpu].active), activeBegin,
std::plus<uint64_t>());
}
for (uint32_t policy = 0; policy < gNPolicies; ++policy) {
if (offset >= gPolicyCpus[policy].size()) continue;
policyBegin = ret[key.uid].policy[policy].begin() + offset;
policyEnd = nextOffset < gPolicyCpus[policy].size() ? policyBegin + CPUS_PER_ENTRY
: ret[key.uid].policy[policy].end();
for (const auto &cpu : gPolicyCpus[policy]) {
std::transform(policyBegin, policyEnd, std::begin(vals[cpu].policy), policyBegin,
std::plus<uint64_t>());
}
}
} while (prevKey = key, !getNextMapKey(gConcurrentMapFd, &prevKey, &key));
if (errno != ENOENT) return {};
for (const auto &[key, value] : ret) {
if (!verifyConcurrentTimes(value)) {
auto val = getUidConcurrentTimes(key, false);
if (val.has_value()) ret[key] = val.value();
}
}
if (lastUpdate && newLastUpdate > *lastUpdate) *lastUpdate = newLastUpdate;
return ret;
}
// Clear all time in state data for a given uid. Returns false on error, true otherwise.
// This is only suitable for clearing data when an app is uninstalled; if called on a UID with
// running tasks it will cause time in state vs. concurrent time totals to be inconsistent for that
// UID.
bool clearUidTimes(uint32_t uid) {
if (!gInitialized && !initGlobals()) return false;
time_key_t key = {.uid = uid};
uint32_t maxFreqCount = 0;
for (const auto &freqList : gPolicyFreqs) {
if (freqList.size() > maxFreqCount) maxFreqCount = freqList.size();
}
tis_val_t zeros = {0};
std::vector<tis_val_t> vals(gNCpus, zeros);
for (key.bucket = 0; key.bucket <= (maxFreqCount - 1) / FREQS_PER_ENTRY; ++key.bucket) {
if (writeToMapEntry(gTisMapFd, &key, vals.data(), BPF_EXIST) && errno != ENOENT)
return false;
if (deleteMapEntry(gTisMapFd, &key) && errno != ENOENT) return false;
}
concurrent_val_t czeros = { .active = {0}, .policy = {0}, };
std::vector<concurrent_val_t> cvals(gNCpus, czeros);
for (key.bucket = 0; key.bucket <= (gNCpus - 1) / CPUS_PER_ENTRY; ++key.bucket) {
if (writeToMapEntry(gConcurrentMapFd, &key, cvals.data(), BPF_EXIST) && errno != ENOENT)
return false;
if (deleteMapEntry(gConcurrentMapFd, &key) && errno != ENOENT) return false;
}
if (deleteMapEntry(gUidLastUpdateMapFd, &uid) && errno != ENOENT) return false;
return true;
}
} // namespace bpf
} // namespace android