diff options
Diffstat (limited to 'tools/xentrace/xentrace.c')
| -rw-r--r-- | tools/xentrace/xentrace.c | 157 |
1 files changed, 96 insertions, 61 deletions
diff --git a/tools/xentrace/xentrace.c b/tools/xentrace/xentrace.c index 26415bdb7d..7f394d2af0 100644 --- a/tools/xentrace/xentrace.c +++ b/tools/xentrace/xentrace.c @@ -23,6 +23,7 @@ #include <string.h> #include <getopt.h> #include <assert.h> +#include <sys/poll.h> #include <xen/xen.h> #include <xen/trace.h> @@ -40,9 +41,6 @@ do { \ /***** Compile time configuration of defaults ********************************/ -/* when we've got more records than this waiting, we log it to the output */ -#define NEW_DATA_THRESH 1 - /* sleep for this long (milliseconds) between checking the trace buffers */ #define POLL_SLEEP_MILLIS 100 @@ -51,8 +49,7 @@ do { \ typedef struct settings_st { char *outfile; - struct timespec poll_sleep; - unsigned long new_data_thresh; + unsigned long poll_sleep; /* milliseconds to sleep between polls */ uint32_t evt_mask; uint32_t cpu_mask; unsigned long tbuf_size; @@ -63,26 +60,16 @@ settings_t opts; int interrupted = 0; /* gets set if we get a SIGHUP */ +static int xc_handle = -1; +static int event_fd = -1; +static int virq_port = -1; + void close_handler(int signal) { interrupted = 1; } /** - * millis_to_timespec - convert a time in milliseconds to a struct timespec - * @millis: time interval in milliseconds - */ -struct timespec millis_to_timespec(unsigned long millis) -{ - struct timespec spec; - - spec.tv_sec = millis / 1000; - spec.tv_nsec = (millis % 1000) * 1000; - - return spec; -} - -/** * write_buffer - write a section of the trace buffer * @cpu - source buffer CPU ID * @start @@ -143,14 +130,8 @@ void write_buffer(unsigned int cpu, unsigned char *start, int size, static void get_tbufs(unsigned long *mfn, unsigned long *size) { - int xc_handle = xc_interface_open(); int ret; - if ( xc_handle < 0 ) - { - exit(EXIT_FAILURE); - } - if(!opts.tbuf_size) opts.tbuf_size = DEFAULT_TBUF_SIZE; @@ -161,8 +142,6 @@ static void get_tbufs(unsigned long *mfn, unsigned long *size) perror("Couldn't enable trace buffers"); exit(1); } - - xc_interface_close(xc_handle); } /** @@ -176,22 +155,12 @@ static void get_tbufs(unsigned long *mfn, unsigned long *size) struct t_buf *map_tbufs(unsigned long tbufs_mfn, unsigned int num, unsigned long size) { - int xc_handle; struct t_buf *tbufs_mapped; - xc_handle = xc_interface_open(); - - if ( xc_handle < 0 ) - { - exit(EXIT_FAILURE); - } - tbufs_mapped = xc_map_foreign_range(xc_handle, DOMID_XEN, size * num, PROT_READ | PROT_WRITE, tbufs_mfn); - xc_interface_close(xc_handle); - if ( tbufs_mapped == 0 ) { PERROR("Failed to mmap trace buffers"); @@ -210,7 +179,6 @@ struct t_buf *map_tbufs(unsigned long tbufs_mfn, unsigned int num, void set_mask(uint32_t mask, int type) { int ret = 0; - int xc_handle = xc_interface_open(); /* for accessing control interface */ if (type == 1) { ret = xc_tbuf_set_cpu_mask(xc_handle, mask); @@ -220,8 +188,6 @@ void set_mask(uint32_t mask, int type) fprintf(stderr, "change evtmask to 0x%x\n", mask); } - xc_interface_close(xc_handle); - if ( ret != 0 ) { PERROR("Failure to get trace buffer pointer from Xen and set the new mask"); @@ -295,7 +261,6 @@ unsigned char **init_rec_ptrs(struct t_buf **meta, unsigned int num) unsigned int get_num_cpus(void) { xc_physinfo_t physinfo = { 0 }; - int xc_handle = xc_interface_open(); int ret; ret = xc_physinfo(xc_handle, &physinfo); @@ -306,11 +271,70 @@ unsigned int get_num_cpus(void) exit(EXIT_FAILURE); } - xc_interface_close(xc_handle); - return physinfo.nr_cpus; } +/** + * event_init - setup to receive the VIRQ_TBUF event + */ +void event_init(void) +{ + int rc; + + rc = xc_evtchn_open(); + if (rc < 0) { + perror(xc_get_last_error()->message); + exit(EXIT_FAILURE); + } + event_fd = rc; + + rc = xc_evtchn_bind_virq(event_fd, VIRQ_TBUF); + if (rc == -1) { + PERROR("failed to bind to VIRQ port"); + exit(EXIT_FAILURE); + } + virq_port = rc; +} + +/** + * wait_for_event_or_timeout - sleep for the specified number of milliseconds, + * or until an VIRQ_TBUF event occurs + */ +void wait_for_event_or_timeout(unsigned long milliseconds) +{ + int rc; + struct pollfd fd = { .fd = event_fd, + .events = POLLIN | POLLERR }; + int port; + + rc = poll(&fd, 1, milliseconds); + if (rc == -1) { + if (errno == EINTR) + return; + PERROR("poll exitted with an error"); + exit(EXIT_FAILURE); + } + + if (rc == 1) { + port = xc_evtchn_pending(event_fd); + if (port == -1) { + PERROR("failed to read port from evtchn"); + exit(EXIT_FAILURE); + } + if (port != virq_port) { + fprintf(stderr, + "unexpected port returned from evtchn (got %d vs expected %d)\n", + port, virq_port); + exit(EXIT_FAILURE); + } + rc = xc_evtchn_unmask(event_fd, port); + if (rc == -1) { + PERROR("failed to write port to evtchn"); + exit(EXIT_FAILURE); + } + } +} + /** * monitor_tbufs - monitor the contents of tbufs and output to a file @@ -330,6 +354,9 @@ int monitor_tbufs(int outfd) unsigned long data_size; + /* prepare to listen for VIRQ_TBUF */ + event_init(); + /* get number of logical CPUs (and therefore number of trace buffers) */ num = get_num_cpus(); @@ -357,14 +384,23 @@ int monitor_tbufs(int outfd) /* Read window information only once. */ cons = meta[i]->cons; prod = meta[i]->prod; - rmb(); /* read prod, then read item. */ - + xen_rmb(); /* read prod, then read item. */ + if ( cons == prod ) continue; - assert(prod > cons); + assert(cons < 2*data_size); + assert(prod < 2*data_size); + + // NB: if (prod<cons), then (prod-cons)%data_size will not yield + // the correct answer because data_size is not a power of 2. + if ( prod < cons ) + window_size = (prod + 2*data_size) - cons; + else + window_size = prod - cons; + assert(window_size > 0); + assert(window_size <= data_size); - window_size = prod - cons; start_offset = cons % data_size; end_offset = prod % data_size; @@ -392,11 +428,11 @@ int monitor_tbufs(int outfd) outfd); } - mb(); /* read buffer, then update cons. */ + xen_mb(); /* read buffer, then update cons. */ meta[i]->cons = prod; } - nanosleep(&opts.poll_sleep, NULL); + wait_for_event_or_timeout(opts.poll_sleep); } /* cleanup */ @@ -416,7 +452,7 @@ int monitor_tbufs(int outfd) #define xstr(x) str(x) #define str(x) #x -const char *program_version = "xentrace v1.1"; +const char *program_version = "xentrace v1.2"; const char *program_bug_address = "<mark.a.williamson@intel.com>"; void usage(void) @@ -435,9 +471,6 @@ void usage(void) " N.B. that the trace buffer cannot be resized.\n" \ " if it has already been set this boot cycle,\n" \ " this argument will be ignored.\n" \ -" -t, --log-thresh=l Set number, l, of new records required to\n" \ -" trigger a write to output (default " \ - xstr(NEW_DATA_THRESH) ").\n" \ " -?, --help Show this message\n" \ " -V, --version Print program version\n" \ "\n" \ @@ -516,12 +549,8 @@ void parse_args(int argc, char **argv) { switch ( option ) { - case 't': /* set new records threshold for logging */ - opts.new_data_thresh = argtol(optarg, 0); - break; - case 's': /* set sleep time (given in milliseconds) */ - opts.poll_sleep = millis_to_timespec(argtol(optarg, 0)); + opts.poll_sleep = argtol(optarg, 0); break; case 'c': /* set new cpu mask for filtering*/ @@ -565,13 +594,19 @@ int main(int argc, char **argv) struct sigaction act; opts.outfile = 0; - opts.poll_sleep = millis_to_timespec(POLL_SLEEP_MILLIS); - opts.new_data_thresh = NEW_DATA_THRESH; + opts.poll_sleep = POLL_SLEEP_MILLIS; opts.evt_mask = 0; opts.cpu_mask = 0; parse_args(argc, argv); - + + xc_handle = xc_interface_open(); + if ( xc_handle < 0 ) + { + perror(xc_get_last_error()->message); + exit(EXIT_FAILURE); + } + if ( opts.evt_mask != 0 ) set_mask(opts.evt_mask, 0); |