# HG changeset patch
# User Michael.Fetterman@xxxxxxxxxxxx
# Date 1202591471 0
# Node ID f904468403b4d47dbebc54c76473c28b24066681
# Parent 9ff80e7b54528e06c8e0dc0ad8d8da09afca7f16
Improve xentrace to use VIRQ_TBUF interrupts as well as a user-specified
polling interval in order to determine when to empty the trace buffers.
Removed the old and unused/unimplemented new_data_threshold logic.
Signed-off-by: Michael A Fetterman <Michael.Fetterman@xxxxxxxxxxxx>
diff -r 9ff80e7b5452 -r f904468403b4 tools/xentrace/xentrace.c
--- a/tools/xentrace/xentrace.c Sat Feb 09 21:11:09 2008 +0000
+++ b/tools/xentrace/xentrace.c Sat Feb 09 21:11:11 2008 +0000
@@ -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;
@@ -63,23 +60,13 @@ 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;
}
/**
@@ -143,13 +130,7 @@ void write_buffer(unsigned int cpu, unsi
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
perror("Couldn't enable trace buffers");
exit(1);
}
-
- xc_interface_close(xc_handle);
}
/**
@@ -176,22 +155,12 @@ struct t_buf *map_tbufs(unsigned long tb
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 @@ void set_mask(uint32_t mask, int type)
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 int get_num_cpus(void)
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);
@@ -306,9 +271,68 @@ 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);
+ }
+ }
}
@@ -329,6 +353,9 @@ int monitor_tbufs(int outfd)
unsigned long size; /* size of a single trace buffer */
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();
@@ -405,7 +432,7 @@ int monitor_tbufs(int outfd)
meta[i]->cons = prod;
}
- nanosleep(&opts.poll_sleep, NULL);
+ wait_for_event_or_timeout(opts.poll_sleep);
}
/* cleanup */
@@ -425,7 +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@xxxxxxxxx>";
void usage(void)
@@ -444,9 +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" \
@@ -525,12 +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*/
@@ -574,13 +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);
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