// Copyright 2006 Google Inc. All Rights Reserved.
// Author: nsanders, menderico
// 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.
// os.cc : os and machine specific implementation
// This file includes an abstracted interface
// for linux-distro specific and HW specific
// interfaces.
#include "os.h"
#include <errno.h>
#include <fcntl.h>
#include <linux/types.h>
#include <malloc.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mman.h>
#include <sys/ioctl.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/ipc.h>
#ifdef HAVE_SYS_SHM_H
#include <sys/shm.h>
#endif
#include <unistd.h>
#ifndef SHM_HUGETLB
#define SHM_HUGETLB 04000 // remove when glibc defines it
#endif
#include <string>
#include <list>
// This file must work with autoconf on its public version,
// so these includes are correct.
#include "sattypes.h"
#include "error_diag.h"
#include "clock.h"
// OsLayer initialization.
OsLayer::OsLayer() {
testmem_ = 0;
testmemsize_ = 0;
totalmemsize_ = 0;
min_hugepages_bytes_ = 0;
reserve_mb_ = 0;
normal_mem_ = true;
use_hugepages_ = false;
use_posix_shm_ = false;
dynamic_mapped_shmem_ = false;
mmapped_allocation_ = false;
shmid_ = 0;
time_initialized_ = 0;
regionsize_ = 0;
regioncount_ = 1;
num_cpus_ = 0;
num_nodes_ = 0;
num_cpus_per_node_ = 0;
error_diagnoser_ = 0;
err_log_callback_ = 0;
error_injection_ = false;
void *pvoid = 0;
address_mode_ = sizeof(pvoid) * 8;
has_clflush_ = false;
has_vector_ = false;
use_flush_page_cache_ = false;
clock_ = NULL;
}
// OsLayer cleanup.
OsLayer::~OsLayer() {
if (error_diagnoser_)
delete error_diagnoser_;
if (clock_)
delete clock_;
}
// OsLayer initialization.
bool OsLayer::Initialize() {
if (!clock_) {
clock_ = new Clock();
}
time_initialized_ = clock_->Now();
// Detect asm support.
GetFeatures();
if (num_cpus_ == 0) {
num_nodes_ = 1;
num_cpus_ = sysconf(_SC_NPROCESSORS_ONLN);
num_cpus_per_node_ = num_cpus_ / num_nodes_;
}
logprintf(5, "Log: %d nodes, %d cpus.\n", num_nodes_, num_cpus_);
sat_assert(CPU_SETSIZE >= num_cpus_);
cpu_sets_.resize(num_nodes_);
cpu_sets_valid_.resize(num_nodes_);
// Create error diagnoser.
error_diagnoser_ = new ErrorDiag();
if (!error_diagnoser_->set_os(this))
return false;
return true;
}
// Machine type detected. Can we implement all these functions correctly?
bool OsLayer::IsSupported() {
if (kOpenSource) {
// There are no explicitly supported systems in open source version.
return true;
}
// This is the default empty implementation.
// SAT won't report full error information.
return false;
}
int OsLayer::AddressMode() {
// Detect 32/64 bit binary.
void *pvoid = 0;
return sizeof(pvoid) * 8;
}
// Translates user virtual to physical address.
uint64 OsLayer::VirtualToPhysical(void *vaddr) {
uint64 frame, shift;
off64_t off = ((uintptr_t)vaddr) / sysconf(_SC_PAGESIZE) * 8;
int fd = open(kPagemapPath, O_RDONLY);
// /proc/self/pagemap is available in kernel >= 2.6.25
if (fd < 0)
return 0;
if (lseek64(fd, off, SEEK_SET) != off || read(fd, &frame, 8) != 8) {
int err = errno;
string errtxt = ErrorString(err);
logprintf(0, "Process Error: failed to access %s with errno %d (%s)\n",
kPagemapPath, err, errtxt.c_str());
if (fd >= 0)
close(fd);
return 0;
}
close(fd);
if (!(frame & (1LL << 63)) || (frame & (1LL << 62)))
return 0;
shift = (frame >> 55) & 0x3f;
frame = (frame & 0x007fffffffffffffLL) << shift;
return frame | ((uintptr_t)vaddr & ((1LL << shift) - 1));
}
// Returns the HD device that contains this file.
string OsLayer::FindFileDevice(string filename) {
return "hdUnknown";
}
// Returns a list of locations corresponding to HD devices.
list<string> OsLayer::FindFileDevices() {
// No autodetection on unknown systems.
list<string> locations;
return locations;
}
// Get HW core features from cpuid instruction.
void OsLayer::GetFeatures() {
#if defined(STRESSAPPTEST_CPU_X86_64) || defined(STRESSAPPTEST_CPU_I686)
unsigned int eax = 1, ebx, ecx, edx;
cpuid(&eax, &ebx, &ecx, &edx);
has_clflush_ = (edx >> 19) & 1;
has_vector_ = (edx >> 26) & 1; // SSE2 caps bit.
logprintf(9, "Log: has clflush: %s, has sse2: %s\n",
has_clflush_ ? "true" : "false",
has_vector_ ? "true" : "false");
#elif defined(STRESSAPPTEST_CPU_PPC)
// All PPC implementations have cache flush instructions.
has_clflush_ = true;
#elif defined(STRESSAPPTEST_CPU_ARMV7A)
// TODO(nsanders): add detect from /proc/cpuinfo or /proc/self/auxv.
// For now assume neon and don't run -W if you don't have it.
has_vector_ = true; // NEON.
#warning "Unsupported CPU type ARMV7A: unable to determine feature set."
#else
#warning "Unsupported CPU type: unable to determine feature set."
#endif
}
// Enable FlushPageCache to be functional instead of a NOP.
void OsLayer::ActivateFlushPageCache(void) {
logprintf(9, "Log: page cache will be flushed as needed\n");
use_flush_page_cache_ = true;
}
// Flush the page cache to ensure reads come from the disk.
bool OsLayer::FlushPageCache(void) {
if (!use_flush_page_cache_)
return true;
// First, ask the kernel to write the cache to the disk.
sync();
// Second, ask the kernel to empty the cache by writing "1" to
// "/proc/sys/vm/drop_caches".
static const char *drop_caches_file = "/proc/sys/vm/drop_caches";
int dcfile = open(drop_caches_file, O_WRONLY);
if (dcfile < 0) {
int err = errno;
string errtxt = ErrorString(err);
logprintf(3, "Log: failed to open %s - err %d (%s)\n",
drop_caches_file, err, errtxt.c_str());
return false;
}
ssize_t bytes_written = write(dcfile, "1", 1);
close(dcfile);
if (bytes_written != 1) {
int err = errno;
string errtxt = ErrorString(err);
logprintf(3, "Log: failed to write %s - err %d (%s)\n",
drop_caches_file, err, errtxt.c_str());
return false;
}
return true;
}
// We need to flush the cacheline here.
void OsLayer::Flush(void *vaddr) {
// Use the generic flush. This function is just so we can override
// this if we are so inclined.
if (has_clflush_) {
OsLayer::FastFlush(vaddr);
}
}
// Run C or ASM copy as appropriate..
bool OsLayer::AdlerMemcpyWarm(uint64 *dstmem, uint64 *srcmem,
unsigned int size_in_bytes,
AdlerChecksum *checksum) {
if (has_vector_) {
return AdlerMemcpyAsm(dstmem, srcmem, size_in_bytes, checksum);
} else {
return AdlerMemcpyWarmC(dstmem, srcmem, size_in_bytes, checksum);
}
}
// Translate physical address to memory module/chip name.
// Assumes interleaving between two memory channels based on the XOR of
// all address bits in the 'channel_hash' mask, with repeated 'channel_width_'
// blocks with bits distributed from each chip in that channel.
int OsLayer::FindDimm(uint64 addr, char *buf, int len) {
if (!channels_) {
snprintf(buf, len, "DIMM Unknown");
return -1;
}
// Find channel by XORing address bits in channel_hash mask.
uint32 low = static_cast<uint32>(addr & channel_hash_);
uint32 high = static_cast<uint32>((addr & channel_hash_) >> 32);
vector<string>& channel = (*channels_)[
__builtin_parity(high) ^ __builtin_parity(low)];
// Find dram chip by finding which byte within the channel
// by address mod channel width, then divide the channel
// evenly among the listed dram chips. Note, this will not work
// with x4 dram.
int chip = (addr % (channel_width_ / 8)) /
((channel_width_ / 8) / channel.size());
string name = channel[chip];
snprintf(buf, len, "%s", name.c_str());
return 1;
}
// Classifies addresses according to "regions"
// This isn't really implemented meaningfully here..
int32 OsLayer::FindRegion(uint64 addr) {
static bool warned = false;
if (regionsize_ == 0) {
regionsize_ = totalmemsize_ / 8;
if (regionsize_ < 512 * kMegabyte)
regionsize_ = 512 * kMegabyte;
regioncount_ = totalmemsize_ / regionsize_;
if (regioncount_ < 1) regioncount_ = 1;
}
int32 region_num = addr / regionsize_;
if (region_num >= regioncount_) {
if (!warned) {
logprintf(0, "Log: region number %d exceeds region count %d\n",
region_num, regioncount_);
warned = true;
}
region_num = region_num % regioncount_;
}
return region_num;
}
// Report which cores are associated with a given region.
cpu_set_t *OsLayer::FindCoreMask(int32 region) {
sat_assert(region >= 0);
region %= num_nodes_;
if (!cpu_sets_valid_[region]) {
CPU_ZERO(&cpu_sets_[region]);
for (int i = 0; i < num_cpus_per_node_; ++i) {
CPU_SET(i + region * num_cpus_per_node_, &cpu_sets_[region]);
}
cpu_sets_valid_[region] = true;
logprintf(5, "Log: Region %d mask 0x%s\n",
region, FindCoreMaskFormat(region).c_str());
}
return &cpu_sets_[region];
}
// Return cores associated with a given region in hex string.
string OsLayer::FindCoreMaskFormat(int32 region) {
cpu_set_t* mask = FindCoreMask(region);
string format = cpuset_format(mask);
if (format.size() < 8)
format = string(8 - format.size(), '0') + format;
return format;
}
// Report an error in an easily parseable way.
bool OsLayer::ErrorReport(const char *part, const char *symptom, int count) {
time_t now = clock_->Now();
int ttf = now - time_initialized_;
if (strlen(symptom) && strlen(part)) {
logprintf(0, "Report Error: %s : %s : %d : %ds\n",
symptom, part, count, ttf);
} else {
// Log something so the error still shows up, but this won't break the
// parser.
logprintf(0, "Warning: Invalid Report Error: "
"%s : %s : %d : %ds\n", symptom, part, count, ttf);
}
return true;
}
// Read the number of hugepages out of the kernel interface in proc.
int64 OsLayer::FindHugePages() {
char buf[65] = "0";
// This is a kernel interface to query the numebr of hugepages
// available in the system.
static const char *hugepages_info_file = "/proc/sys/vm/nr_hugepages";
int hpfile = open(hugepages_info_file, O_RDONLY);
ssize_t bytes_read = read(hpfile, buf, 64);
close(hpfile);
if (bytes_read <= 0) {
logprintf(12, "Log: /proc/sys/vm/nr_hugepages "
"read did not provide data\n");
return 0;
}
if (bytes_read == 64) {
logprintf(0, "Process Error: /proc/sys/vm/nr_hugepages "
"is surprisingly large\n");
return 0;
}
// Add a null termintation to be string safe.
buf[bytes_read] = '\0';
// Read the page count.
int64 pages = strtoull(buf, NULL, 10); // NOLINT
return pages;
}
int64 OsLayer::FindFreeMemSize() {
int64 size = 0;
int64 minsize = 0;
if (totalmemsize_ > 0)
return totalmemsize_;
int64 pages = sysconf(_SC_PHYS_PAGES);
int64 avpages = sysconf(_SC_AVPHYS_PAGES);
int64 pagesize = sysconf(_SC_PAGESIZE);
int64 physsize = pages * pagesize;
int64 avphyssize = avpages * pagesize;
// Assume 2MB hugepages.
int64 hugepagesize = FindHugePages() * 2 * kMegabyte;
if ((pages == -1) || (pagesize == -1)) {
logprintf(0, "Process Error: sysconf could not determine memory size.\n");
return 0;
}
// We want to leave enough stuff for things to run.
// If the user specified a minimum amount of memory to expect, require that.
// Otherwise, if more than 2GB is present, leave 192M + 5% for other stuff.
// If less than 2GB is present use 85% of what's available.
// These are fairly arbitrary numbers that seem to work OK.
//
// TODO(nsanders): is there a more correct way to determine target
// memory size?
if (hugepagesize > 0) {
if (min_hugepages_bytes_ > 0) {
minsize = min_hugepages_bytes_;
} else {
minsize = hugepagesize;
}
} else {
if (physsize < 2048LL * kMegabyte) {
minsize = ((pages * 85) / 100) * pagesize;
} else {
minsize = ((pages * 95) / 100) * pagesize - (192 * kMegabyte);
}
// Make sure that at least reserve_mb_ is left for the system.
if (reserve_mb_ > 0) {
int64 totalsize = pages * pagesize;
int64 reserve_kb = reserve_mb_ * kMegabyte;
if (reserve_kb > totalsize) {
logprintf(0, "Procedural Error: %lld is bigger than the total memory "
"available %lld\n", reserve_kb, totalsize);
} else if (reserve_kb > totalsize - minsize) {
logprintf(5, "Warning: Overriding memory to use: original %lld, "
"current %lld\n", minsize, totalsize - reserve_kb);
minsize = totalsize - reserve_kb;
}
}
}
// Use hugepage sizing if available.
if (hugepagesize > 0) {
if (hugepagesize < minsize) {
logprintf(0, "Procedural Error: Not enough hugepages. "
"%lldMB available < %lldMB required.\n",
hugepagesize / kMegabyte,
minsize / kMegabyte);
// Require the calculated minimum amount of memory.
size = minsize;
} else {
// Require that we get all hugepages.
size = hugepagesize;
}
} else {
// Require the calculated minimum amount of memory.
size = minsize;
}
logprintf(5, "Log: Total %lld MB. Free %lld MB. Hugepages %lld MB. "
"Targeting %lld MB (%lld%%)\n",
physsize / kMegabyte,
avphyssize / kMegabyte,
hugepagesize / kMegabyte,
size / kMegabyte,
size * 100 / physsize);
totalmemsize_ = size;
return size;
}
// Allocates all memory available.
int64 OsLayer::AllocateAllMem() {
int64 length = FindFreeMemSize();
bool retval = AllocateTestMem(length, 0);
if (retval)
return length;
else
return 0;
}
// Allocate the target memory. This may be from malloc, hugepage pool
// or other platform specific sources.
bool OsLayer::AllocateTestMem(int64 length, uint64 paddr_base) {
// Try hugepages first.
void *buf = 0;
sat_assert(length >= 0);
if (paddr_base)
logprintf(0, "Process Error: non zero paddr_base %#llx is not supported,"
" ignore.\n", paddr_base);
// Determine optimal memory allocation path.
bool prefer_hugepages = false;
bool prefer_posix_shm = false;
bool prefer_dynamic_mapping = false;
// Are there enough hugepages?
int64 hugepagesize = FindHugePages() * 2 * kMegabyte;
// TODO(nsanders): Is there enough /dev/shm? Is there enough free memeory?
if ((length >= 1400LL * kMegabyte) && (address_mode_ == 32)) {
prefer_dynamic_mapping = true;
prefer_posix_shm = true;
logprintf(3, "Log: Prefer POSIX shared memory allocation.\n");
logprintf(3, "Log: You may need to run "
"'sudo mount -o remount,size=100\% /dev/shm.'\n");
} else if (hugepagesize >= length) {
prefer_hugepages = true;
logprintf(3, "Log: Prefer using hugepage allocation.\n");
} else {
logprintf(3, "Log: Prefer plain malloc memory allocation.\n");
}
#ifdef HAVE_SYS_SHM_H
// Allocate hugepage mapped memory.
if (prefer_hugepages) {
do { // Allow break statement.
int shmid;
void *shmaddr;
if ((shmid = shmget(2, length,
SHM_HUGETLB | IPC_CREAT | SHM_R | SHM_W)) < 0) {
int err = errno;
string errtxt = ErrorString(err);
logprintf(3, "Log: failed to allocate shared hugepage "
"object - err %d (%s)\n",
err, errtxt.c_str());
logprintf(3, "Log: sysctl -w vm.nr_hugepages=XXX allows hugepages.\n");
break;
}
shmaddr = shmat(shmid, NULL, 0);
if (shmaddr == reinterpret_cast<void*>(-1)) {
int err = errno;
string errtxt = ErrorString(err);
logprintf(0, "Log: failed to attach shared "
"hugepage object - err %d (%s).\n",
err, errtxt.c_str());
if (shmctl(shmid, IPC_RMID, NULL) < 0) {
int err = errno;
string errtxt = ErrorString(err);
logprintf(0, "Log: failed to remove shared "
"hugepage object - err %d (%s).\n",
err, errtxt.c_str());
}
break;
}
use_hugepages_ = true;
shmid_ = shmid;
buf = shmaddr;
logprintf(0, "Log: Using shared hugepage object 0x%x at %p.\n",
shmid, shmaddr);
} while (0);
}
if ((!use_hugepages_) && prefer_posix_shm) {
do {
int shm_object;
void *shmaddr = NULL;
shm_object = shm_open("/stressapptest", O_CREAT | O_RDWR, S_IRWXU);
if (shm_object < 0) {
int err = errno;
string errtxt = ErrorString(err);
logprintf(3, "Log: failed to allocate shared "
"smallpage object - err %d (%s)\n",
err, errtxt.c_str());
break;
}
if (0 > ftruncate(shm_object, length)) {
int err = errno;
string errtxt = ErrorString(err);
logprintf(3, "Log: failed to ftruncate shared "
"smallpage object - err %d (%s)\n",
err, errtxt.c_str());
break;
}
// 32 bit linux apps can only use ~1.4G of address space.
// Use dynamic mapping for allocations larger than that.
// Currently perf hit is ~10% for this.
if (prefer_dynamic_mapping) {
dynamic_mapped_shmem_ = true;
} else {
// Do a full mapping here otherwise.
shmaddr = mmap64(NULL, length, PROT_READ | PROT_WRITE,
MAP_SHARED | MAP_NORESERVE | MAP_LOCKED | MAP_POPULATE,
shm_object, 0);
if (shmaddr == reinterpret_cast<void*>(-1)) {
int err = errno;
string errtxt = ErrorString(err);
logprintf(0, "Log: failed to map shared "
"smallpage object - err %d (%s).\n",
err, errtxt.c_str());
break;
}
}
use_posix_shm_ = true;
shmid_ = shm_object;
buf = shmaddr;
char location_message[256] = "";
if (dynamic_mapped_shmem_) {
sprintf(location_message, "mapped as needed");
} else {
sprintf(location_message, "at %p", shmaddr);
}
logprintf(0, "Log: Using posix shared memory object 0x%x %s.\n",
shm_object, location_message);
} while (0);
shm_unlink("/stressapptest");
}
#endif // HAVE_SYS_SHM_H
if (!use_hugepages_ && !use_posix_shm_) {
// If the page size is what SAT is expecting explicitly perform mmap()
// allocation.
if (sysconf(_SC_PAGESIZE) >= 4096) {
void *map_buf = mmap(NULL, length, PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
if (map_buf != MAP_FAILED) {
buf = map_buf;
mmapped_allocation_ = true;
logprintf(0, "Log: Using mmap() allocation at %p.\n", buf);
}
}
if (!mmapped_allocation_) {
// Use memalign to ensure that blocks are aligned enough for disk direct
// IO.
buf = static_cast<char*>(memalign(4096, length));
if (buf) {
logprintf(0, "Log: Using memaligned allocation at %p.\n", buf);
} else {
logprintf(0, "Process Error: memalign returned 0\n");
if ((length >= 1499LL * kMegabyte) && (address_mode_ == 32)) {
logprintf(0, "Log: You are trying to allocate > 1.4G on a 32 "
"bit process. Please setup shared memory.\n");
}
}
}
}
testmem_ = buf;
if (buf || dynamic_mapped_shmem_) {
testmemsize_ = length;
} else {
testmemsize_ = 0;
}
return (buf != 0) || dynamic_mapped_shmem_;
}
// Free the test memory.
void OsLayer::FreeTestMem() {
if (testmem_) {
if (use_hugepages_) {
#ifdef HAVE_SYS_SHM_H
shmdt(testmem_);
shmctl(shmid_, IPC_RMID, NULL);
#endif
} else if (use_posix_shm_) {
if (!dynamic_mapped_shmem_) {
munmap(testmem_, testmemsize_);
}
close(shmid_);
} else if (mmapped_allocation_) {
munmap(testmem_, testmemsize_);
} else {
free(testmem_);
}
testmem_ = 0;
testmemsize_ = 0;
}
}
// Prepare the target memory. It may requre mapping in, or this may be a noop.
void *OsLayer::PrepareTestMem(uint64 offset, uint64 length) {
sat_assert((offset + length) <= testmemsize_);
if (dynamic_mapped_shmem_) {
// TODO(nsanders): Check if we can support MAP_NONBLOCK,
// and evaluate performance hit from not using it.
#ifdef HAVE_MMAP64
void * mapping = mmap64(NULL, length, PROT_READ | PROT_WRITE,
MAP_SHARED | MAP_NORESERVE | MAP_LOCKED | MAP_POPULATE,
shmid_, offset);
#else
void * mapping = mmap(NULL, length, PROT_READ | PROT_WRITE,
MAP_SHARED | MAP_NORESERVE | MAP_LOCKED | MAP_POPULATE,
shmid_, offset);
#endif
if (mapping == MAP_FAILED) {
string errtxt = ErrorString(errno);
logprintf(0, "Process Error: PrepareTestMem mmap64(%llx, %llx) failed. "
"error: %s.\n",
offset, length, errtxt.c_str());
sat_assert(0);
}
return mapping;
}
return reinterpret_cast<void*>(reinterpret_cast<char*>(testmem_) + offset);
}
// Release the test memory resources, if any.
void OsLayer::ReleaseTestMem(void *addr, uint64 offset, uint64 length) {
if (dynamic_mapped_shmem_) {
int retval = munmap(addr, length);
if (retval == -1) {
string errtxt = ErrorString(errno);
logprintf(0, "Process Error: ReleaseTestMem munmap(%p, %llx) failed. "
"error: %s.\n",
addr, length, errtxt.c_str());
sat_assert(0);
}
}
}
// No error polling on unknown systems.
int OsLayer::ErrorPoll() {
return 0;
}
// Generally, poll for errors once per second.
void OsLayer::ErrorWait() {
sat_sleep(1);
return;
}
// Open a PCI bus-dev-func as a file and return its file descriptor.
// Error is indicated by return value less than zero.
int OsLayer::PciOpen(int bus, int device, int function) {
char dev_file[256];
snprintf(dev_file, sizeof(dev_file), "/proc/bus/pci/%02x/%02x.%x",
bus, device, function);
int fd = open(dev_file, O_RDWR);
if (fd == -1) {
logprintf(0, "Process Error: Unable to open PCI bus %d, device %d, "
"function %d (errno %d).\n",
bus, device, function, errno);
return -1;
}
return fd;
}
// Read and write functions to access PCI config.
uint32 OsLayer::PciRead(int fd, uint32 offset, int width) {
// Strict aliasing rules lawyers will cause data corruption
// on cast pointers in some gccs.
union {
uint32 l32;
uint16 l16;
uint8 l8;
} datacast;
datacast.l32 = 0;
uint32 size = width / 8;
sat_assert((width == 32) || (width == 16) || (width == 8));
sat_assert(offset <= (256 - size));
if (lseek(fd, offset, SEEK_SET) < 0) {
logprintf(0, "Process Error: Can't seek %x\n", offset);
return 0;
}
if (read(fd, &datacast, size) != static_cast<ssize_t>(size)) {
logprintf(0, "Process Error: Can't read %x\n", offset);
return 0;
}
// Extract the data.
switch (width) {
case 8:
sat_assert(&(datacast.l8) == reinterpret_cast<uint8*>(&datacast));
return datacast.l8;
case 16:
sat_assert(&(datacast.l16) == reinterpret_cast<uint16*>(&datacast));
return datacast.l16;
case 32:
return datacast.l32;
}
return 0;
}
void OsLayer::PciWrite(int fd, uint32 offset, uint32 value, int width) {
// Strict aliasing rules lawyers will cause data corruption
// on cast pointers in some gccs.
union {
uint32 l32;
uint16 l16;
uint8 l8;
} datacast;
datacast.l32 = 0;
uint32 size = width / 8;
sat_assert((width == 32) || (width == 16) || (width == 8));
sat_assert(offset <= (256 - size));
// Cram the data into the right alignment.
switch (width) {
case 8:
sat_assert(&(datacast.l8) == reinterpret_cast<uint8*>(&datacast));
datacast.l8 = value;
case 16:
sat_assert(&(datacast.l16) == reinterpret_cast<uint16*>(&datacast));
datacast.l16 = value;
case 32:
datacast.l32 = value;
}
if (lseek(fd, offset, SEEK_SET) < 0) {
logprintf(0, "Process Error: Can't seek %x\n", offset);
return;
}
if (write(fd, &datacast, size) != static_cast<ssize_t>(size)) {
logprintf(0, "Process Error: Can't write %x to %x\n", datacast.l32, offset);
return;
}
return;
}
// Open dev msr.
int OsLayer::OpenMSR(uint32 core, uint32 address) {
char buf[256];
snprintf(buf, sizeof(buf), "/dev/cpu/%d/msr", core);
int fd = open(buf, O_RDWR);
if (fd < 0)
return fd;
uint32 pos = lseek(fd, address, SEEK_SET);
if (pos != address) {
close(fd);
logprintf(5, "Log: can't seek to msr %x, cpu %d\n", address, core);
return -1;
}
return fd;
}
bool OsLayer::ReadMSR(uint32 core, uint32 address, uint64 *data) {
int fd = OpenMSR(core, address);
if (fd < 0)
return false;
// Read from the msr.
bool res = (sizeof(*data) == read(fd, data, sizeof(*data)));
if (!res)
logprintf(5, "Log: Failed to read msr %x core %d\n", address, core);
close(fd);
return res;
}
bool OsLayer::WriteMSR(uint32 core, uint32 address, uint64 *data) {
int fd = OpenMSR(core, address);
if (fd < 0)
return false;
// Write to the msr
bool res = (sizeof(*data) == write(fd, data, sizeof(*data)));
if (!res)
logprintf(5, "Log: Failed to write msr %x core %d\n", address, core);
close(fd);
return res;
}
// Extract bits [n+len-1, n] from a 32 bit word.
// so GetBitField(0x0f00, 8, 4) == 0xf.
uint32 OsLayer::GetBitField(uint32 val, uint32 n, uint32 len) {
return (val >> n) & ((1<<len) - 1);
}
// Generic CPU stress workload that would work on any CPU/Platform.
// Float-point array moving average calculation.
bool OsLayer::CpuStressWorkload() {
double float_arr[100];
double sum = 0;
#ifdef HAVE_RAND_R
unsigned int seed = 12345;
#endif
// Initialize array with random numbers.
for (int i = 0; i < 100; i++) {
#ifdef HAVE_RAND_R
float_arr[i] = rand_r(&seed);
if (rand_r(&seed) % 2)
float_arr[i] *= -1.0;
#else
srand(time(NULL));
float_arr[i] = rand(); // NOLINT
if (rand() % 2) // NOLINT
float_arr[i] *= -1.0;
#endif
}
// Calculate moving average.
for (int i = 0; i < 100000000; i++) {
float_arr[i % 100] =
(float_arr[i % 100] + float_arr[(i + 1) % 100] +
float_arr[(i + 99) % 100]) / 3;
sum += float_arr[i % 100];
}
// Artificial printf so the loops do not get optimized away.
if (sum == 0.0)
logprintf(12, "Log: I'm Feeling Lucky!\n");
return true;
}