Enhance perf to collect KVM guest os statistics from host side
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From: Ingo Molnar on 17 Mar 2010 04:20 * Frank Ch. Eigler <fche(a)redhat.com> wrote: > Hi - > > On Tue, Mar 16, 2010 at 06:04:10PM -0500, Anthony Liguori wrote: > > [...] > > The only way to really address this is to change the interaction. > > Instead of running perf externally to qemu, we should support a perf > > command in the qemu monitor that can then tie directly to the perf > > tooling. That gives us the best possible user experience. > > To what extent could this be solved with less crossing of > isolation/abstraction layers, if the perfctr facilities were properly > virtualized? [...] Note, 'perfctr' is a different out-of-tree Linux kernel project run by someone else: it offers the /dev/perfctr special-purpose device that allows raw, unabstracted, low-level access to the PMU. I suspect the one you wanted to mention here is called 'perf' or 'perf events'. (and used to be called 'performance counters' or 'perfcounters' until it got renamed about a year ago) Thanks, Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Avi Kivity on 17 Mar 2010 04:30 On 03/17/2010 10:16 AM, Ingo Molnar wrote: > * Avi Kivity<avi(a)redhat.com> wrote: > > >> Monitoring guests from the host is useful for kvm developers, but less so >> for users. >> > Guest space profiling is easy, and 'perf kvm' is not about that. (plain 'perf' > will work if a proper paravirt channel is opened to the host) > > I think you might have misunderstood the purpose and role of the 'perf kvm' > patch here? 'perf kvm' is aimed at KVM developers: it is them who improve KVM > code, not guest kernel users. > Of course I understood it. My point was that 'perf kvm' serves a tiny minority of users. That doesn't mean it isn't useful, just that it doesn't satisfy all needs by itself. -- Do not meddle in the internals of kernels, for they are subtle and quick to panic. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Ingo Molnar on 17 Mar 2010 05:00 * Avi Kivity <avi(a)redhat.com> wrote: > On 03/17/2010 10:16 AM, Ingo Molnar wrote: > >* Avi Kivity<avi(a)redhat.com> wrote: > > > >> Monitoring guests from the host is useful for kvm developers, but less so > >> for users. > > > > Guest space profiling is easy, and 'perf kvm' is not about that. (plain > > 'perf' will work if a proper paravirt channel is opened to the host) > > > > I think you might have misunderstood the purpose and role of the 'perf > > kvm' patch here? 'perf kvm' is aimed at KVM developers: it is them who > > improve KVM code, not guest kernel users. > > Of course I understood it. My point was that 'perf kvm' serves a tiny > minority of users. [...] I hope you wont be disappointed to learn that 100% of Linux, all 13+ million lines of it, was and is being developed by a tiny, tiny, tiny minority of users ;-) > [...] That doesn't mean it isn't useful, just that it doesn't satisfy all > needs by itself. Of course - and it doesnt bring world peace either. One step at a time. Thanks, Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Zhang, Yanmin on 17 Mar 2010 05:30 On Tue, 2010-03-16 at 10:47 +0100, Ingo Molnar wrote: > * Zhang, Yanmin <yanmin_zhang(a)linux.intel.com> wrote: > > > On Tue, 2010-03-16 at 15:48 +0800, Zhang, Yanmin wrote: > > > On Tue, 2010-03-16 at 07:41 +0200, Avi Kivity wrote: > > > > On 03/16/2010 07:27 AM, Zhang, Yanmin wrote: > > > > > From: Zhang, Yanmin<yanmin_zhang(a)linux.intel.com> > > > > > > > > > > Based on the discussion in KVM community, I worked out the patch to support > > > > > perf to collect guest os statistics from host side. This patch is implemented > > > > > with Ingo, Peter and some other guys' kind help. Yang Sheng pointed out a > > > > > critical bug and provided good suggestions with other guys. I really appreciate > > > > > their kind help. > > > > > > > > > > The patch adds new subcommand kvm to perf. > > > > > > > > > > perf kvm top > > > > > perf kvm record > > > > > perf kvm report > > > > > perf kvm diff > > > > > > > > > > The new perf could profile guest os kernel except guest os user space, but it > > > > > could summarize guest os user space utilization per guest os. > > > > > > > > > > Below are some examples. > > > > > 1) perf kvm top > > > > > [root(a)lkp-ne01 norm]# perf kvm --host --guest --guestkallsyms=/home/ymzhang/guest/kallsyms > > > > > --guestmodules=/home/ymzhang/guest/modules top > > > > > > > > > > > > > > > > > Thanks for your kind comments. > > > > > > > Excellent, support for guest kernel != host kernel is critical (I can't > > > > remember the last time I ran same kernels). > > > > > > > > How would we support multiple guests with different kernels? > > > With the patch, 'perf kvm report --sort pid" could show > > > summary statistics for all guest os instances. Then, use > > > parameter --pid of 'perf kvm record' to collect single problematic instance data. > > Sorry. I found currently --pid isn't process but a thread (main thread). > > > > Ingo, > > > > Is it possible to support a new parameter or extend --inherit, so 'perf > > record' and 'perf top' could collect data on all threads of a process when > > the process is running? > > > > If not, I need add a new ugly parameter which is similar to --pid to filter > > out process data in userspace. > > Yeah. For maximum utility i'd suggest to extend --pid to include this, and > introduce --tid for the previous, limited-to-a-single-task functionality. > > Most users would expect --pid to work like a 'late attach' - i.e. to work like > strace -f or like a gdb attach. Thanks Ingo, Avi. I worked out below patch against tip/master of March 15th. Subject: [PATCH] Change perf's parameter --pid to process-wide collection From: Zhang, Yanmin <yanmin_zhang(a)linux.intel.com> Change parameter -p (--pid) to real process pid and add -t (--tid) meaning thread id. Now, --pid means perf collects the statistics of all threads of the process, while --tid means perf just collect the statistics of that thread. BTW, the patch fixes a bug of 'perf stat -p'. 'perf stat' always configures attr->disabled=1 if it isn't a system-wide collection. If there is a '-p' and no forks, 'perf stat -p' doesn't collect any data. In addition, the while(!done) in run_perf_stat consumes 100% single cpu time which has bad impact on running workload. I added a sleep(1) in the loop. Signed-off-by: Zhang Yanmin <yanmin_zhang(a)linux.intel.com> --- diff -Nraup linux-2.6_tipmaster0315/tools/perf/builtin-record.c linux-2.6_tipmaster0315_perfpid/tools/perf/builtin-record.c --- linux-2.6_tipmaster0315/tools/perf/builtin-record.c 2010-03-16 08:59:54.896488489 +0800 +++ linux-2.6_tipmaster0315_perfpid/tools/perf/builtin-record.c 2010-03-17 16:30:17.755551706 +0800 @@ -27,7 +27,7 @@ #include <unistd.h> #include <sched.h> -static int fd[MAX_NR_CPUS][MAX_COUNTERS]; +static int *fd[MAX_NR_CPUS][MAX_COUNTERS]; static long default_interval = 0; @@ -43,6 +43,9 @@ static int raw_samples = 0; static int system_wide = 0; static int profile_cpu = -1; static pid_t target_pid = -1; +static pid_t target_tid = -1; +static int *all_tids = NULL; +static int thread_num = 0; static pid_t child_pid = -1; static int inherit = 1; static int force = 0; @@ -60,7 +63,7 @@ static struct timeval this_read; static u64 bytes_written = 0; -static struct pollfd event_array[MAX_NR_CPUS * MAX_COUNTERS]; +static struct pollfd *event_array; static int nr_poll = 0; static int nr_cpu = 0; @@ -77,7 +80,7 @@ struct mmap_data { unsigned int prev; }; -static struct mmap_data mmap_array[MAX_NR_CPUS][MAX_COUNTERS]; +static struct mmap_data *mmap_array[MAX_NR_CPUS][MAX_COUNTERS]; static unsigned long mmap_read_head(struct mmap_data *md) { @@ -225,11 +228,12 @@ static struct perf_header_attr *get_head return h_attr; } -static void create_counter(int counter, int cpu, pid_t pid, bool forks) +static void create_counter(int counter, int cpu, bool forks) { char *filter = filters[counter]; struct perf_event_attr *attr = attrs + counter; struct perf_header_attr *h_attr; + int thread_index; int track = !counter; /* only the first counter needs these */ int ret; struct { @@ -280,117 +284,124 @@ static void create_counter(int counter, if (forks) attr->enable_on_exec = 1; + for (thread_index = 0; thread_index < thread_num; thread_index++) { try_again: - fd[nr_cpu][counter] = sys_perf_event_open(attr, pid, cpu, group_fd, 0); + fd[nr_cpu][counter][thread_index] = sys_perf_event_open(attr, + all_tids[thread_index], cpu, group_fd, 0); - if (fd[nr_cpu][counter] < 0) { - int err = errno; + if (fd[nr_cpu][counter][thread_index] < 0) { + int err = errno; - if (err == EPERM || err == EACCES) - die("Permission error - are you root?\n" - "\t Consider tweaking /proc/sys/kernel/perf_event_paranoid.\n"); - else if (err == ENODEV && profile_cpu != -1) - die("No such device - did you specify an out-of-range profile CPU?\n"); + if (err == EPERM || err == EACCES) + die("Permission error - are you root?\n" + "\t Consider tweaking /proc/sys/kernel/perf_event_paranoid.\n"); + else if (err == ENODEV && profile_cpu != -1) + die("No such device - did you specify an out-of-range profile CPU?\n"); - /* - * If it's cycles then fall back to hrtimer - * based cpu-clock-tick sw counter, which - * is always available even if no PMU support: - */ - if (attr->type == PERF_TYPE_HARDWARE - && attr->config == PERF_COUNT_HW_CPU_CYCLES) { + /* + * If it's cycles then fall back to hrtimer + * based cpu-clock-tick sw counter, which + * is always available even if no PMU support: + */ + if (attr->type == PERF_TYPE_HARDWARE + && attr->config == PERF_COUNT_HW_CPU_CYCLES) { - if (verbose) - warning(" ... trying to fall back to cpu-clock-ticks\n"); - attr->type = PERF_TYPE_SOFTWARE; - attr->config = PERF_COUNT_SW_CPU_CLOCK; - goto try_again; - } - printf("\n"); - error("perfcounter syscall returned with %d (%s)\n", - fd[nr_cpu][counter], strerror(err)); + if (verbose) + warning(" ... trying to fall back to cpu-clock-ticks\n"); + attr->type = PERF_TYPE_SOFTWARE; + attr->config = PERF_COUNT_SW_CPU_CLOCK; + goto try_again; + } + printf("\n"); + error("perfcounter syscall returned with %d (%s)\n", + fd[nr_cpu][counter][thread_index], + strerror(err)); #if defined(__i386__) || defined(__x86_64__) - if (attr->type == PERF_TYPE_HARDWARE && err == EOPNOTSUPP) - die("No hardware sampling interrupt available. No APIC? If so then you can boot the kernel with the \"lapic\" boot parameter to force-enable it.\n"); + if (attr->type == PERF_TYPE_HARDWARE && err == EOPNOTSUPP) + die("No hardware sampling interrupt available. No APIC? If so then you can boot the kernel with the \"lapic\" boot parameter to force-enable it.\n"); #endif - die("No CONFIG_PERF_EVENTS=y kernel support configured?\n"); - exit(-1); - } + die("No CONFIG_PERF_EVENTS=y kernel support configured?\n"); + exit(-1); + } - h_attr = get_header_attr(attr, counter); - if (h_attr == NULL) - die("nomem\n"); + h_attr = get_header_attr(attr, counter); + if (h_attr == NULL) + die("nomem\n"); + + if (!file_new) { + if (memcmp(&h_attr->attr, attr, sizeof(*attr))) { + fprintf(stderr, "incompatible append\n"); + exit(-1); + } + } - if (!file_new) { - if (memcmp(&h_attr->attr, attr, sizeof(*attr))) { - fprintf(stderr, "incompatible append\n"); + if (read(fd[nr_cpu][counter][thread_index], &read_data, sizeof(read_data)) == -1) { + perror("Unable to read perf file descriptor\n"); exit(-1); } - } - - if (read(fd[nr_cpu][counter], &read_data, sizeof(read_data)) == -1) { - perror("Unable to read perf file descriptor\n"); - exit(-1); - } - if (perf_header_attr__add_id(h_attr, read_data.id) < 0) { - pr_warning("Not enough memory to add id\n"); - exit(-1); - } + if (perf_header_attr__add_id(h_attr, read_data.id) < 0) { + pr_warning("Not enough memory to add id\n"); + exit(-1); + } - assert(fd[nr_cpu][counter] >= 0); - fcntl(fd[nr_cpu][counter], F_SETFL, O_NONBLOCK); + assert(fd[nr_cpu][counter][thread_index] >= 0); + fcntl(fd[nr_cpu][counter][thread_index], F_SETFL, O_NONBLOCK); - /* - * First counter acts as the group leader: - */ - if (group && group_fd == -1) - group_fd = fd[nr_cpu][counter]; - if (multiplex && multiplex_fd == -1) - multiplex_fd = fd[nr_cpu][counter]; + /* + * First counter acts as the group leader: + */ + if (group && group_fd == -1) + group_fd = fd[nr_cpu][counter][thread_index]; + if (multiplex && multiplex_fd == -1) + multiplex_fd = fd[nr_cpu][counter][thread_index]; - if (multiplex && fd[nr_cpu][counter] != multiplex_fd) { + if (multiplex && fd[nr_cpu][counter][thread_index] != multiplex_fd) { - ret = ioctl(fd[nr_cpu][counter], PERF_EVENT_IOC_SET_OUTPUT, multiplex_fd); - assert(ret != -1); - } else { - event_array[nr_poll].fd = fd[nr_cpu][counter]; - event_array[nr_poll].events = POLLIN; - nr_poll++; - - mmap_array[nr_cpu][counter].counter = counter; - mmap_array[nr_cpu][counter].prev = 0; - mmap_array[nr_cpu][counter].mask = mmap_pages*page_size - 1; - mmap_array[nr_cpu][counter].base = mmap(NULL, (mmap_pages+1)*page_size, - PROT_READ|PROT_WRITE, MAP_SHARED, fd[nr_cpu][counter], 0); - if (mmap_array[nr_cpu][counter].base == MAP_FAILED) { - error("failed to mmap with %d (%s)\n", errno, strerror(errno)); - exit(-1); + ret = ioctl(fd[nr_cpu][counter][thread_index], PERF_EVENT_IOC_SET_OUTPUT, multiplex_fd); + assert(ret != -1); + } else { + event_array[nr_poll].fd = fd[nr_cpu][counter][thread_index]; + event_array[nr_poll].events = POLLIN; + nr_poll++; + + mmap_array[nr_cpu][counter][thread_index].counter = counter; + mmap_array[nr_cpu][counter][thread_index].prev = 0; + mmap_array[nr_cpu][counter][thread_index].mask = mmap_pages*page_size - 1; + mmap_array[nr_cpu][counter][thread_index].base = mmap(NULL, + (mmap_pages+1)*page_size, + PROT_READ|PROT_WRITE, MAP_SHARED, + fd[nr_cpu][counter][thread_index], + 0); + if (mmap_array[nr_cpu][counter][thread_index].base == MAP_FAILED) { + error("failed to mmap with %d (%s)\n", errno, strerror(errno)); + exit(-1); + } } - } - if (filter != NULL) { - ret = ioctl(fd[nr_cpu][counter], - PERF_EVENT_IOC_SET_FILTER, filter); - if (ret) { - error("failed to set filter with %d (%s)\n", errno, - strerror(errno)); - exit(-1); + if (filter != NULL) { + ret = ioctl(fd[nr_cpu][counter][thread_index], + PERF_EVENT_IOC_SET_FILTER, filter); + if (ret) { + error("failed to set filter with %d (%s)\n", errno, + strerror(errno)); + exit(-1); + } } - } - ioctl(fd[nr_cpu][counter], PERF_EVENT_IOC_ENABLE); + ioctl(fd[nr_cpu][counter][thread_index], PERF_EVENT_IOC_ENABLE); + } } -static void open_counters(int cpu, pid_t pid, bool forks) +static void open_counters(int cpu, bool forks) { int counter; group_fd = -1; for (counter = 0; counter < nr_counters; counter++) - create_counter(counter, cpu, pid, forks); + create_counter(counter, cpu, forks); nr_cpu++; } @@ -425,7 +436,7 @@ static int __cmd_record(int argc, const int err; unsigned long waking = 0; int child_ready_pipe[2], go_pipe[2]; - const bool forks = target_pid == -1 && argc > 0; + const bool forks = target_tid == -1 && argc > 0; char buf; page_size = sysconf(_SC_PAGE_SIZE); @@ -534,7 +545,7 @@ static int __cmd_record(int argc, const child_pid = pid; if (!system_wide) - target_pid = pid; + target_tid = pid; close(child_ready_pipe[1]); close(go_pipe[0]); @@ -550,11 +561,11 @@ static int __cmd_record(int argc, const if ((!system_wide && !inherit) || profile_cpu != -1) { - open_counters(profile_cpu, target_pid, forks); + open_counters(profile_cpu, forks); } else { nr_cpus = read_cpu_map(); for (i = 0; i < nr_cpus; i++) - open_counters(cpumap[i], target_pid, forks); + open_counters(cpumap[i], forks); } if (file_new) { @@ -579,7 +590,7 @@ static int __cmd_record(int argc, const } if (!system_wide && profile_cpu == -1) - event__synthesize_thread(target_pid, process_synthesized_event, + event__synthesize_thread(target_tid, process_synthesized_event, session); else event__synthesize_threads(process_synthesized_event, session); @@ -602,11 +613,15 @@ static int __cmd_record(int argc, const for (;;) { int hits = samples; + int thread; for (i = 0; i < nr_cpu; i++) { for (counter = 0; counter < nr_counters; counter++) { - if (mmap_array[i][counter].base) - mmap_read(&mmap_array[i][counter]); + for (thread = 0; + thread < thread_num; thread++) { + if (mmap_array[i][counter][thread].base) + mmap_read(&mmap_array[i][counter][thread]); + } } } @@ -619,8 +634,13 @@ static int __cmd_record(int argc, const if (done) { for (i = 0; i < nr_cpu; i++) { - for (counter = 0; counter < nr_counters; counter++) - ioctl(fd[i][counter], PERF_EVENT_IOC_DISABLE); + for (counter = 0; counter < nr_counters; + counter++) { + for (thread = 0; + thread < thread_num; thread++) + ioctl(fd[i][counter][thread], + PERF_EVENT_IOC_DISABLE); + } } } } @@ -653,6 +673,8 @@ static const struct option options[] = { "event filter", parse_filter), OPT_INTEGER('p', "pid", &target_pid, "record events on existing pid"), + OPT_INTEGER('t', "tid", &target_tid, + "record events on existing thread id"), OPT_INTEGER('r', "realtime", &realtime_prio, "collect data with this RT SCHED_FIFO priority"), OPT_BOOLEAN('R', "raw-samples", &raw_samples, @@ -693,10 +715,11 @@ static const struct option options[] = { int cmd_record(int argc, const char **argv, const char *prefix __used) { int counter; + int i,j; argc = parse_options(argc, argv, options, record_usage, PARSE_OPT_STOP_AT_NON_OPTION); - if (!argc && target_pid == -1 && !system_wide && profile_cpu == -1) + if (!argc && target_tid == -1 && !system_wide && profile_cpu == -1) usage_with_options(record_usage, options); symbol__init(); @@ -707,6 +730,37 @@ int cmd_record(int argc, const char **ar attrs[0].config = PERF_COUNT_HW_CPU_CYCLES; } + if (target_pid != -1) { + target_tid = target_pid; + thread_num = find_all_tid(target_pid, &all_tids); + if (thread_num <= 0) { + fprintf(stderr, "Can't find all threads of pid %d\n", + target_pid); + usage_with_options(record_usage, options); + } + } else { + all_tids=malloc(sizeof(int)); + if (!all_tids) + return -ENOMEM; + + all_tids[0] = target_tid; + thread_num = 1; + } + + for (i = 0; i < MAX_NR_CPUS; i++) { + for (j = 0; j < MAX_COUNTERS; j++) { + fd[i][j] = malloc(sizeof(int)*thread_num); + mmap_array[i][j] = malloc( + sizeof(struct mmap_data)*thread_num); + if (!fd[i][j] || !mmap_array[i][j]) + return -ENOMEM; + } + } + event_array = malloc( + sizeof(struct pollfd)*MAX_NR_CPUS*MAX_COUNTERS*thread_num); + if (!event_array) + return -ENOMEM; + /* * User specified count overrides default frequency. */ diff -Nraup linux-2.6_tipmaster0315/tools/perf/builtin-stat.c linux-2.6_tipmaster0315_perfpid/tools/perf/builtin-stat.c --- linux-2.6_tipmaster0315/tools/perf/builtin-stat.c 2010-03-16 08:59:54.892460680 +0800 +++ linux-2.6_tipmaster0315_perfpid/tools/perf/builtin-stat.c 2010-03-17 16:30:25.484062179 +0800 @@ -46,6 +46,7 @@ #include "util/debug.h" #include "util/header.h" #include "util/cpumap.h" +#include "util/thread.h" #include <sys/prctl.h> #include <math.h> @@ -74,10 +75,14 @@ static int run_count = 1; static int inherit = 1; static int scale = 1; static pid_t target_pid = -1; +static pid_t target_tid = -1; +static int *all_tids = NULL; +static int thread_num = 0; static pid_t child_pid = -1; static int null_run = 0; +static bool forks = false; -static int fd[MAX_NR_CPUS][MAX_COUNTERS]; +static int *fd[MAX_NR_CPUS][MAX_COUNTERS]; static int event_scaled[MAX_COUNTERS]; @@ -140,9 +145,10 @@ struct stats runtime_branches_stats; #define ERR_PERF_OPEN \ "Error: counter %d, sys_perf_event_open() syscall returned with %d (%s)\n" -static void create_perf_stat_counter(int counter, int pid) +static void create_perf_stat_counter(int counter) { struct perf_event_attr *attr = attrs + counter; + int thread; if (scale) attr->read_format = PERF_FORMAT_TOTAL_TIME_ENABLED | @@ -152,20 +158,24 @@ static void create_perf_stat_counter(int unsigned int cpu; for (cpu = 0; cpu < nr_cpus; cpu++) { - fd[cpu][counter] = sys_perf_event_open(attr, -1, cpumap[cpu], -1, 0); - if (fd[cpu][counter] < 0 && verbose) + fd[cpu][counter][0] = sys_perf_event_open(attr, -1, cpumap[cpu], -1, 0); + if (fd[cpu][counter][0] < 0 && verbose) fprintf(stderr, ERR_PERF_OPEN, counter, - fd[cpu][counter], strerror(errno)); + fd[cpu][counter][0], strerror(errno)); } } else { attr->inherit = inherit; - attr->disabled = 1; + if (forks) + attr->disabled = 1; attr->enable_on_exec = 1; - fd[0][counter] = sys_perf_event_open(attr, pid, -1, -1, 0); - if (fd[0][counter] < 0 && verbose) - fprintf(stderr, ERR_PERF_OPEN, counter, - fd[0][counter], strerror(errno)); + for (thread = 0; thread < thread_num; thread++) { + fd[0][counter][thread] = sys_perf_event_open(attr, + all_tids[thread], -1, -1, 0); + if (fd[0][counter][thread] < 0 && verbose) + fprintf(stderr, ERR_PERF_OPEN, counter, + fd[0][counter][thread], strerror(errno)); + } } } @@ -190,25 +200,29 @@ static void read_counter(int counter) unsigned int cpu; size_t res, nv; int scaled; - int i; + int i, thread; count[0] = count[1] = count[2] = 0; nv = scale ? 3 : 1; for (cpu = 0; cpu < nr_cpus; cpu++) { - if (fd[cpu][counter] < 0) - continue; - - res = read(fd[cpu][counter], single_count, nv * sizeof(u64)); - assert(res == nv * sizeof(u64)); - - close(fd[cpu][counter]); - fd[cpu][counter] = -1; - - count[0] += single_count[0]; - if (scale) { - count[1] += single_count[1]; - count[2] += single_count[2]; + + for (thread = 0; thread < thread_num; thread++) { + if (fd[cpu][counter][thread] < 0) + continue; + + res = read(fd[cpu][counter][thread], + single_count, nv * sizeof(u64)); + assert(res == nv * sizeof(u64)); + + close(fd[cpu][counter][thread]); + fd[cpu][counter][thread] = -1; + + count[0] += single_count[0]; + if (scale) { + count[1] += single_count[1]; + count[2] += single_count[2]; + } } } @@ -251,11 +265,11 @@ static int run_perf_stat(int argc __used unsigned long long t0, t1; int status = 0; int counter; - int pid = target_pid; + int pid = target_tid; int child_ready_pipe[2], go_pipe[2]; - const bool forks = (target_pid == -1 && argc > 0); char buf; + forks = (target_tid == -1 && argc > 0); if (!system_wide) nr_cpus = 1; @@ -307,10 +321,12 @@ static int run_perf_stat(int argc __used if (read(child_ready_pipe[0], &buf, 1) == -1) perror("unable to read pipe"); close(child_ready_pipe[0]); + + all_tids[0] = pid; } for (counter = 0; counter < nr_counters; counter++) - create_perf_stat_counter(counter, pid); + create_perf_stat_counter(counter); /* * Enable counters and exec the command: @@ -321,7 +337,7 @@ static int run_perf_stat(int argc __used close(go_pipe[1]); wait(&status); } else { - while(!done); + while(!done) sleep(1); } t1 = rdclock(); @@ -429,12 +445,12 @@ static void print_stat(int argc, const c fprintf(stderr, "\n"); fprintf(stderr, " Performance counter stats for "); - if(target_pid == -1) { + if(target_tid == -1) { fprintf(stderr, "\'%s", argv[0]); for (i = 1; i < argc; i++) fprintf(stderr, " %s", argv[i]); }else - fprintf(stderr, "task pid \'%d", target_pid); + fprintf(stderr, "task pid \'%d", target_tid); fprintf(stderr, "\'"); if (run_count > 1) @@ -459,7 +475,7 @@ static volatile int signr = -1; static void skip_signal(int signo) { - if(target_pid != -1) + if(target_tid != -1) done = 1; signr = signo; @@ -488,8 +504,10 @@ static const struct option options[] = { parse_events), OPT_BOOLEAN('i', "inherit", &inherit, "child tasks inherit counters"), - OPT_INTEGER('p', "pid", &target_pid, + OPT_INTEGER('p', "pid", &target_tid, "stat events on existing pid"), + OPT_INTEGER('t', "tid", &target_tid, + "stat events on existing tid"), OPT_BOOLEAN('a', "all-cpus", &system_wide, "system-wide collection from all CPUs"), OPT_BOOLEAN('c', "scale", &scale, @@ -506,10 +524,11 @@ static const struct option options[] = { int cmd_stat(int argc, const char **argv, const char *prefix __used) { int status; + int i,j; argc = parse_options(argc, argv, options, stat_usage, PARSE_OPT_STOP_AT_NON_OPTION); - if (!argc && target_pid == -1) + if (!argc && (target_pid == -1 || target_tid == -1)) usage_with_options(stat_usage, options); if (run_count <= 0) usage_with_options(stat_usage, options); @@ -525,6 +544,32 @@ int cmd_stat(int argc, const char **argv else nr_cpus = 1; + if (target_pid != -1) { + target_tid = target_pid; + thread_num = find_all_tid(target_pid, &all_tids); + if (thread_num <= 0) { + fprintf(stderr, "Can't find all threads of pid %d\n", + target_pid); + usage_with_options(stat_usage, options); + } + + } else { + all_tids=malloc(sizeof(int)); + if (!all_tids) + return -ENOMEM; + + all_tids[0] = target_tid; + thread_num = 1; + } + + for (i = 0; i < MAX_NR_CPUS; i++) { + for (j = 0; j < MAX_COUNTERS; j++) { + fd[i][j] = malloc(sizeof(int)*thread_num); + if (!fd[i][j]) + return -ENOMEM; + } + } + /* * We dont want to block the signals - that would cause * child tasks to inherit that and Ctrl-C would not work. diff -Nraup linux-2.6_tipmaster0315/tools/perf/builtin-top.c linux-2.6_tipmaster0315_perfpid/tools/perf/builtin-top.c --- linux-2.6_tipmaster0315/tools/perf/builtin-top.c 2010-03-16 08:59:54.760470652 +0800 +++ linux-2.6_tipmaster0315_perfpid/tools/perf/builtin-top.c 2010-03-17 16:30:35.316716557 +0800 @@ -55,7 +55,8 @@ #include <linux/unistd.h> #include <linux/types.h> -static int fd[MAX_NR_CPUS][MAX_COUNTERS]; +static int *fd[MAX_NR_CPUS][MAX_COUNTERS]; +static int *all_tids = NULL; static int system_wide = 0; @@ -64,7 +65,9 @@ static int default_interval = 0; static int count_filter = 5; static int print_entries; +static int target_tid = -1; static int target_pid = -1; +static int thread_num = 0; static int inherit = 0; static int profile_cpu = -1; static int nr_cpus = 0; @@ -524,13 +527,15 @@ static void print_sym_table(void) if (target_pid != -1) printf(" (target_pid: %d", target_pid); + else if (target_tid != -1) + printf(" (target_tid: %d", target_tid); else printf(" (all"); if (profile_cpu != -1) printf(", cpu: %d)\n", profile_cpu); else { - if (target_pid != -1) + if (target_tid != -1) printf(")\n"); else printf(", %d CPUs)\n", nr_cpus); @@ -1124,16 +1129,21 @@ static void perf_session__mmap_read_coun md->prev = old; } -static struct pollfd event_array[MAX_NR_CPUS * MAX_COUNTERS]; -static struct mmap_data mmap_array[MAX_NR_CPUS][MAX_COUNTERS]; +static struct pollfd *event_array; +static struct mmap_data *mmap_array[MAX_NR_CPUS][MAX_COUNTERS]; static void perf_session__mmap_read(struct perf_session *self) { - int i, counter; + int i, counter, thread_index; for (i = 0; i < nr_cpus; i++) { for (counter = 0; counter < nr_counters; counter++) - perf_session__mmap_read_counter(self, &mmap_array[i][counter]); + for (thread_index = 0; + thread_index < thread_num; + thread_index++) { + perf_session__mmap_read_counter(self, + &mmap_array[i][counter][thread_index]); + } } } @@ -1144,9 +1154,10 @@ static void start_counter(int i, int cou { struct perf_event_attr *attr; int cpu; + int thread_index; cpu = profile_cpu; - if (target_pid == -1 && profile_cpu == -1) + if (target_tid == -1 && profile_cpu == -1) cpu = cpumap[i]; attr = attrs + counter; @@ -1162,55 +1173,58 @@ static void start_counter(int i, int cou attr->inherit = (cpu < 0) && inherit; attr->mmap = 1; + for (thread_index = 0; thread_index < thread_num; thread_index++) { try_again: - fd[i][counter] = sys_perf_event_open(attr, target_pid, cpu, group_fd, 0); + fd[i][counter][thread_index] = sys_perf_event_open(attr, + all_tids[thread_index], cpu, group_fd, 0); + + if (fd[i][counter][thread_index] < 0) { + int err = errno; - if (fd[i][counter] < 0) { - int err = errno; + if (err == EPERM || err == EACCES) + die("No permission - are you root?\n"); + /* + * If it's cycles then fall back to hrtimer + * based cpu-clock-tick sw counter, which + * is always available even if no PMU support: + */ + if (attr->type == PERF_TYPE_HARDWARE + && attr->config == PERF_COUNT_HW_CPU_CYCLES) { + + if (verbose) + warning(" ... trying to fall back to cpu-clock-ticks\n"); + + attr->type = PERF_TYPE_SOFTWARE; + attr->config = PERF_COUNT_SW_CPU_CLOCK; + goto try_again; + } + printf("\n"); + error("perfcounter syscall returned with %d (%s)\n", + fd[i][counter][thread_index], strerror(err)); + die("No CONFIG_PERF_EVENTS=y kernel support configured?\n"); + exit(-1); + } + assert(fd[i][counter][thread_index] >= 0); + fcntl(fd[i][counter][thread_index], F_SETFL, O_NONBLOCK); - if (err == EPERM || err == EACCES) - die("No permission - are you root?\n"); /* - * If it's cycles then fall back to hrtimer - * based cpu-clock-tick sw counter, which - * is always available even if no PMU support: + * First counter acts as the group leader: */ - if (attr->type == PERF_TYPE_HARDWARE - && attr->config == PERF_COUNT_HW_CPU_CYCLES) { + if (group && group_fd == -1) + group_fd = fd[i][counter][thread_index]; - if (verbose) - warning(" ... trying to fall back to cpu-clock-ticks\n"); - - attr->type = PERF_TYPE_SOFTWARE; - attr->config = PERF_COUNT_SW_CPU_CLOCK; - goto try_again; - } - printf("\n"); - error("perfcounter syscall returned with %d (%s)\n", - fd[i][counter], strerror(err)); - die("No CONFIG_PERF_EVENTS=y kernel support configured?\n"); - exit(-1); + event_array[nr_poll].fd = fd[i][counter][thread_index]; + event_array[nr_poll].events = POLLIN; + nr_poll++; + + mmap_array[i][counter][thread_index].counter = counter; + mmap_array[i][counter][thread_index].prev = 0; + mmap_array[i][counter][thread_index].mask = mmap_pages*page_size - 1; + mmap_array[i][counter][thread_index].base = mmap(NULL, (mmap_pages+1)*page_size, + PROT_READ, MAP_SHARED, fd[i][counter][thread_index], 0); + if (mmap_array[i][counter][thread_index].base == MAP_FAILED) + die("failed to mmap with %d (%s)\n", errno, strerror(errno)); } - assert(fd[i][counter] >= 0); - fcntl(fd[i][counter], F_SETFL, O_NONBLOCK); - - /* - * First counter acts as the group leader: - */ - if (group && group_fd == -1) - group_fd = fd[i][counter]; - - event_array[nr_poll].fd = fd[i][counter]; - event_array[nr_poll].events = POLLIN; - nr_poll++; - - mmap_array[i][counter].counter = counter; - mmap_array[i][counter].prev = 0; - mmap_array[i][counter].mask = mmap_pages*page_size - 1; - mmap_array[i][counter].base = mmap(NULL, (mmap_pages+1)*page_size, - PROT_READ, MAP_SHARED, fd[i][counter], 0); - if (mmap_array[i][counter].base == MAP_FAILED) - die("failed to mmap with %d (%s)\n", errno, strerror(errno)); } static int __cmd_top(void) @@ -1226,8 +1240,8 @@ static int __cmd_top(void) if (session == NULL) return -ENOMEM; - if (target_pid != -1) - event__synthesize_thread(target_pid, event__process, session); + if (target_tid != -1) + event__synthesize_thread(target_tid, event__process, session); else event__synthesize_threads(event__process, session); @@ -1238,7 +1252,7 @@ static int __cmd_top(void) } /* Wait for a minimal set of events before starting the snapshot */ - poll(event_array, nr_poll, 100); + poll(&event_array[0], nr_poll, 100); perf_session__mmap_read(session); @@ -1282,6 +1296,8 @@ static const struct option options[] = { "event period to sample"), OPT_INTEGER('p', "pid", &target_pid, "profile events on existing pid"), + OPT_INTEGER('t', "tid", &target_tid, + "profile events on existing tid"), OPT_BOOLEAN('a', "all-cpus", &system_wide, "system-wide collection from all CPUs"), OPT_INTEGER('C', "CPU", &profile_cpu, @@ -1322,6 +1338,7 @@ static const struct option options[] = { int cmd_top(int argc, const char **argv, const char *prefix __used) { int counter; + int i,j; page_size = sysconf(_SC_PAGE_SIZE); @@ -1329,8 +1346,39 @@ int cmd_top(int argc, const char **argv, if (argc) usage_with_options(top_usage, options); + if (target_pid != -1) { + target_tid = target_pid; + thread_num = find_all_tid(target_pid, &all_tids); + if (thread_num <= 0) { + fprintf(stderr, "Can't find all threads of pid %d\n", + target_pid); + usage_with_options(top_usage, options); + } + } else { + all_tids=malloc(sizeof(int)); + if (!all_tids) + return -ENOMEM; + + all_tids[0] = target_tid; + thread_num = 1; + } + + for (i = 0; i < MAX_NR_CPUS; i++) { + for (j = 0; j < MAX_COUNTERS; j++) { + fd[i][j] = malloc(sizeof(int)*thread_num); + mmap_array[i][j] = malloc( + sizeof(struct mmap_data)*thread_num); + if (!fd[i][j] || !mmap_array[i][j]) + return -ENOMEM; + } + } + event_array = malloc( + sizeof(struct pollfd)*MAX_NR_CPUS*MAX_COUNTERS*thread_num); + if (!event_array) + return -ENOMEM; + /* CPU and PID are mutually exclusive */ - if (target_pid != -1 && profile_cpu != -1) { + if (target_tid > 0 && profile_cpu != -1) { printf("WARNING: PID switch overriding CPU\n"); sleep(1); profile_cpu = -1; @@ -1371,7 +1419,7 @@ int cmd_top(int argc, const char **argv, attrs[counter].sample_period = default_interval; } - if (target_pid != -1 || profile_cpu != -1) + if (target_tid != -1 || profile_cpu != -1) nr_cpus = 1; else nr_cpus = read_cpu_map(); diff -Nraup linux-2.6_tipmaster0315/tools/perf/util/thread.c linux-2.6_tipmaster0315_perfpid/tools/perf/util/thread.c --- linux-2.6_tipmaster0315/tools/perf/util/thread.c 2010-03-16 08:59:54.892460680 +0800 +++ linux-2.6_tipmaster0315_perfpid/tools/perf/util/thread.c 2010-03-17 14:07:25.725218425 +0800 @@ -7,6 +7,37 @@ #include "util.h" #include "debug.h" +int find_all_tid(int pid, int ** all_tid) +{ + char name[256]; + int items; + struct dirent **namelist = NULL; + int ret = 0; + int i; + + sprintf(name, "/proc/%d/task", pid); + items = scandir(name, &namelist, NULL, NULL); + if (items <= 0) + return -ENOENT; + *all_tid = malloc(sizeof(int) * items); + if (!*all_tid) { + ret = -ENOMEM; + goto failure; + } + + for (i = 0; i < items; i++) + (*all_tid)[i] = atoi(namelist[i]->d_name); + + ret = items; + +failure: + for (i=0; i<items; i++) + free(namelist[i]); + free(namelist); + + return ret; +} + void map_groups__init(struct map_groups *self) { int i; @@ -348,3 +379,4 @@ struct symbol *map_groups__find_symbol(s return NULL; } + diff -Nraup linux-2.6_tipmaster0315/tools/perf/util/thread.h linux-2.6_tipmaster0315_perfpid/tools/perf/util/thread.h --- linux-2.6_tipmaster0315/tools/perf/util/thread.h 2010-03-16 08:59:54.764469663 +0800 +++ linux-2.6_tipmaster0315_perfpid/tools/perf/util/thread.h 2010-03-17 14:03:09.628322688 +0800 @@ -23,6 +23,7 @@ struct thread { int comm_len; }; +int find_all_tid(int pid, int ** all_tid); void map_groups__init(struct map_groups *self); int thread__set_comm(struct thread *self, const char *comm); int thread__comm_len(struct thread *self); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Avi Kivity on 17 Mar 2010 05:50
On 03/17/2010 11:28 AM, Sheng Yang wrote: > >> I'm not sure if vmexit does break NMI context or not. Hardware NMI context >> isn't reentrant till a IRET. YangSheng would like to double check it. >> > After more check, I think VMX won't remained NMI block state for host. That's > means, if NMI happened and processor is in VMX non-root mode, it would only > result in VMExit, with a reason indicate that it's due to NMI happened, but no > more state change in the host. > > So in that meaning, there _is_ a window between VMExit and KVM handle the NMI. > Moreover, I think we _can't_ stop the re-entrance of NMI handling code because > "int $2" don't have effect to block following NMI. > That's pretty bad, as NMI runs on a separate stack (via IST). So if another NMI happens while our int $2 is running, the stack will be corrupted. > And if the NMI sequence is not important(I think so), then we need to generate > a real NMI in current vmexit-after code. Seems let APIC send a NMI IPI to > itself is a good idea. > > I am debugging a patch based on apic->send_IPI_self(NMI_VECTOR) to replace > "int $2". Something unexpected is happening... > I think you need DM_NMI for that to work correctly. An alternative is to call the NMI handler directly. -- error compiling committee.c: too many arguments to function -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |