X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=lib%2Ftimeval.c;h=f687c96520fda0feda1115e2ba0d204043072fc5;hb=4816a18f33380a33d381b77d41df39113c94500d;hp=e5071403227f111c56fa8d5e95b8e3ebb0138fa1;hpb=fdce775cc57314913b663c3efbdce25cdf61591e;p=sliver-openvswitch.git diff --git a/lib/timeval.c b/lib/timeval.c index e50714032..f687c9652 100644 --- a/lib/timeval.c +++ b/lib/timeval.c @@ -1,5 +1,5 @@ /* - * Copyright (c) 2008, 2009, 2010, 2011, 2012 Nicira, Inc. + * Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013 Nicira, Inc. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. @@ -16,11 +16,7 @@ #include #include "timeval.h" -#include #include -#if HAVE_EXECINFO_H -#include -#endif #include #include #include @@ -32,13 +28,20 @@ #include "dummy.h" #include "dynamic-string.h" #include "fatal-signal.h" +#include "hash.h" +#include "hmap.h" #include "signals.h" #include "unixctl.h" #include "util.h" #include "vlog.h" -#ifndef HAVE_EXECINFO_H -#define HAVE_EXECINFO_H 0 +/* backtrace() from is really useful, but it is not signal safe + * everywhere, such as on x86-64. */ +#if HAVE_BACKTRACE && !defined __x86_64__ +# define USE_BACKTRACE 1 +# include +#else +# define USE_BACKTRACE 0 #endif VLOG_DEFINE_THIS_MODULE(timeval); @@ -72,6 +75,10 @@ static long long int deadline = LLONG_MAX; struct trace { void *backtrace[32]; /* Populated by backtrace(). */ size_t n_frames; /* Number of frames in 'backtrace'. */ + + /* format_backtraces() helper data. */ + struct hmap_node node; + size_t count; }; #define MAX_TRACES 50 @@ -92,6 +99,20 @@ static void timespec_add(struct timespec *sum, const struct timespec *a, const struct timespec *b); static unixctl_cb_func backtrace_cb; +#if !USE_BACKTRACE +static int +backtrace(void **buffer OVS_UNUSED, int size OVS_UNUSED) +{ + NOT_REACHED(); +} + +static char ** +backtrace_symbols(void *const *buffer OVS_UNUSED, int size OVS_UNUSED) +{ + NOT_REACHED(); +} +#endif /* !USE_BACKTRACE */ + /* Initializes the timetracking module, if not already initialized. */ static void time_init(void) @@ -103,9 +124,19 @@ time_init(void) } inited = true; + /* The implementation of backtrace() in glibc does some one time + * initialization which is not signal safe. This can cause deadlocks if + * run from the signal handler. As a workaround, force the initialization + * to happen here. */ + if (USE_BACKTRACE) { + void *bt[1]; + + backtrace(bt, ARRAY_SIZE(bt)); + } + memset(traces, 0, sizeof traces); - if (HAVE_EXECINFO_H && CACHE_TIME) { + if (USE_BACKTRACE && CACHE_TIME) { unixctl_command_register("backtrace", "", 0, 0, backtrace_cb, NULL); } @@ -301,7 +332,7 @@ time_alarm(unsigned int secs) time_refresh(); now = time_msec(); - msecs = secs * 1000; + msecs = secs * 1000LL; block_sigalrm(&oldsigs); deadline = now < LLONG_MAX - msecs ? now + msecs : LLONG_MAX; @@ -392,15 +423,13 @@ sigalrm_handler(int sig_nr OVS_UNUSED) wall_tick = true; monotonic_tick = true; -#if HAVE_EXECINFO_H - if (CACHE_TIME) { + if (USE_BACKTRACE && CACHE_TIME) { struct trace *trace = &traces[trace_head]; trace->n_frames = backtrace(trace->backtrace, ARRAY_SIZE(trace->backtrace)); trace_head = (trace_head + 1) % MAX_TRACES; } -#endif } static void @@ -425,13 +454,13 @@ block_sigalrm(sigset_t *oldsigs) sigset_t sigalrm; sigemptyset(&sigalrm); sigaddset(&sigalrm, SIGALRM); - xsigprocmask(SIG_BLOCK, &sigalrm, oldsigs); + xpthread_sigmask(SIG_BLOCK, &sigalrm, oldsigs); } static void unblock_sigalrm(const sigset_t *oldsigs) { - xsigprocmask(SIG_SETMASK, oldsigs, NULL); + xpthread_sigmask(SIG_SETMASK, oldsigs, NULL); } long long int @@ -491,7 +520,7 @@ log_poll_interval(long long int last_wakeup) { long long int interval = time_msec() - last_wakeup; - if (interval >= 1000) { + if (interval >= 1000 && !warp_offset.tv_sec && !warp_offset.tv_nsec) { const struct rusage *last_rusage = get_recent_rusage(); struct rusage rusage; @@ -577,13 +606,40 @@ get_cpu_usage(void) return cpu_usage; } -static void -format_backtraces(struct ds *ds) +static uint32_t +hash_trace(struct trace *trace) +{ + return hash_bytes(trace->backtrace, + trace->n_frames * sizeof *trace->backtrace, 0); +} + +static struct trace * +trace_map_lookup(struct hmap *trace_map, struct trace *key) +{ + struct trace *value; + + HMAP_FOR_EACH_WITH_HASH (value, node, hash_trace(key), trace_map) { + if (key->n_frames == value->n_frames + && !memcmp(key->backtrace, value->backtrace, + key->n_frames * sizeof *key->backtrace)) { + return value; + } + } + return NULL; +} + +/* Appends a string to 'ds' representing backtraces recorded at regular + * intervals in the recent past. This information can be used to get a sense + * of what the process has been spending the majority of time doing. Will + * ommit any backtraces which have not occurred at least 'min_count' times. */ +void +format_backtraces(struct ds *ds, size_t min_count) { time_init(); -#if HAVE_EXECINFO_H - if (CACHE_TIME) { + if (USE_BACKTRACE && CACHE_TIME) { + struct hmap trace_map = HMAP_INITIALIZER(&trace_map); + struct trace *trace, *next; sigset_t oldsigs; size_t i; @@ -591,16 +647,34 @@ format_backtraces(struct ds *ds) for (i = 0; i < MAX_TRACES; i++) { struct trace *trace = &traces[i]; + struct trace *map_trace; + + if (!trace->n_frames) { + continue; + } + + map_trace = trace_map_lookup(&trace_map, trace); + if (map_trace) { + map_trace->count++; + } else { + hmap_insert(&trace_map, &trace->node, hash_trace(trace)); + trace->count = 1; + } + } + + HMAP_FOR_EACH_SAFE (trace, next, node, &trace_map) { char **frame_strs; size_t j; - if (!trace->n_frames) { + hmap_remove(&trace_map, &trace->node); + + if (trace->count < min_count) { continue; } frame_strs = backtrace_symbols(trace->backtrace, trace->n_frames); - ds_put_format(ds, "Backtrace %zu\n", i + 1); + ds_put_format(ds, "Count %zu\n", trace->count); for (j = 0; j < trace->n_frames; j++) { ds_put_format(ds, "%s\n", frame_strs[j]); } @@ -608,10 +682,11 @@ format_backtraces(struct ds *ds) free(frame_strs); } + hmap_destroy(&trace_map); + ds_chomp(ds, '\n'); unblock_sigalrm(&oldsigs); } -#endif } /* Unixctl interface. */ @@ -659,8 +734,8 @@ backtrace_cb(struct unixctl_conn *conn, { struct ds ds = DS_EMPTY_INITIALIZER; - assert(HAVE_EXECINFO_H && CACHE_TIME); - format_backtraces(&ds); + ovs_assert(USE_BACKTRACE && CACHE_TIME); + format_backtraces(&ds, 0); unixctl_command_reply(conn, ds_cstr(&ds)); ds_destroy(&ds); }