From: Masami Hiramatsu <mhiramat@redhat.com>
To: systemtap<systemtap@sources.redhat.com>
Subject: [PATCH 2/3] Signal-based file switching support for old relay
Date: Wed, 09 Sep 2009 16:33:00 -0000 [thread overview]
Message-ID: <20090909163432.22599.64729.stgit@localhost.localdomain> (raw)
In-Reply-To: <20090909163420.22599.87922.stgit@localhost.localdomain>
* runtime/staprun/relay_old.c (switch_oldoutfile): New function for file
switching.
(process_subbufs): Use switch_oldoutfile.
(reader_thread): Block SIGUSR1 and SIGUSR2 in default, and use ppoll()
instead of poll() for receiving SIGUSR2.
(switchfile_handler): Send SIGUSR2 signal to reader threads for file
switching.
(init_oldrelayfs): Assign switchfile_handler to SIGUSR1.
---
runtime/staprun/relay_old.c | 83 +++++++++++++++++++++++++++++++++++++------
1 files changed, 71 insertions(+), 12 deletions(-)
diff --git a/runtime/staprun/relay_old.c b/runtime/staprun/relay_old.c
index 0254173..64bdf1c 100644
--- a/runtime/staprun/relay_old.c
+++ b/runtime/staprun/relay_old.c
@@ -19,6 +19,7 @@ static int proc_fd[NR_CPUS];
static FILE *percpu_tmpfile[NR_CPUS];
static char *relay_buffer[NR_CPUS];
static pthread_t reader[NR_CPUS];
+static int switch_file[NR_CPUS];
static int bulkmode = 0;
unsigned subbuf_size = 0;
unsigned n_subbufs = 0;
@@ -214,6 +215,22 @@ err1:
}
+static int switch_oldoutfile(int cpu, struct switchfile_ctrl_block *scb)
+{
+ dbug(3, "thread %d switching file\n", cpu);
+ if (percpu_tmpfile[cpu])
+ fclose(percpu_tmpfile[cpu]);
+ else
+ close(out_fd[cpu]);
+ scb->fnum ++;
+ if (fnum_max && scb->fnum == fnum_max)
+ scb->rmfile = 1;
+ if (open_oldoutfile(scb->fnum, cpu, scb->rmfile) < 0) {
+ perr("Couldn't open file for cpu %d, exiting.", cpu);
+ return -1;
+ }
+ return 0;
+}
/**
* process_subbufs - write ready subbufs to disk
*/
@@ -238,11 +255,7 @@ static int process_subbufs(struct _stp_buf_info *info,
len = (subbuf_size - sizeof(padding)) - padding;
scb->wsize += len;
if (fsize_max && scb->wsize > fsize_max) {
- fclose(percpu_tmpfile[cpu]);
- scb->fnum ++;
- if (fnum_max && scb->fnum == fnum_max)
- scb->rmfile = 1;
- if (open_oldoutfile(scb->fnum, cpu, scb->rmfile) < 0) {
+ if (switch_oldoutfile(cpu, scb) < 0) {
perr("Couldn't open file for cpu %d, exiting.", cpu);
return -1;
}
@@ -264,6 +277,8 @@ static int process_subbufs(struct _stp_buf_info *info,
/**
* reader_thread - per-cpu channel buffer reader
*/
+static void empty_handler(int __attribute__((unused)) sig) { /* do nothing */ }
+
static void *reader_thread(void *data)
{
int rc;
@@ -272,7 +287,23 @@ static void *reader_thread(void *data)
struct _stp_consumed_info consumed_info;
unsigned subbufs_consumed;
cpu_set_t cpu_mask;
+ struct timespec tim = {.tv_sec=0, .tv_nsec=200000000}, *timeout = &tim;
struct switchfile_ctrl_block scb = {0, 0, 0};
+ sigset_t sigs;
+ struct sigaction sa;
+
+ sigemptyset(&sigs);
+ sigaddset(&sigs,SIGUSR1);
+ sigaddset(&sigs,SIGUSR2);
+ pthread_sigmask(SIG_BLOCK, &sigs, NULL);
+
+ sigfillset(&sigs);
+ sigdelset(&sigs,SIGUSR2);
+
+ sa.sa_handler = empty_handler;
+ sa.sa_flags = 0;
+ sigemptyset(&sa.sa_mask);
+ sigaction(SIGUSR2, &sa, NULL);
CPU_ZERO(&cpu_mask);
CPU_SET(cpu, &cpu_mask);
@@ -281,9 +312,17 @@ static void *reader_thread(void *data)
pollfd.fd = relay_fd[cpu];
pollfd.events = POLLIN;
+#ifdef NEED_PPOLL
+ /* Without a real ppoll, there is a small race condition that could */
+ /* block ppoll(). So use a timeout to prevent that. */
+ timeout->tv_sec = 10;
+ timeout->tv_nsec = 0;
+#else
+ timeout = NULL;
+#endif
do {
- rc = poll(&pollfd, 1, -1);
+ rc = ppoll(&pollfd, 1, timeout, &sigs);
if (rc < 0) {
if (errno != EINTR) {
_perr("poll error");
@@ -292,6 +331,12 @@ static void *reader_thread(void *data)
err("WARNING: poll warning: %s\n", strerror(errno));
rc = 0;
}
+ if (switch_file[cpu]) {
+ switch_file[cpu] = 0;
+ if (switch_oldoutfile(cpu, &scb) < 0)
+ break;
+ scb.wsize = 0;
+ }
rc = read(proc_fd[cpu], &status[cpu].info, sizeof(struct _stp_buf_info));
rc = process_subbufs(&status[cpu].info, &scb);
@@ -324,12 +369,7 @@ int write_realtime_data(void *data, ssize_t nb)
ssize_t bw;
global_scb.wsize += nb;
if (fsize_max && global_scb.wsize > fsize_max) {
- close(out_fd[0]);
- global_scb.fnum++;
- if (fnum_max && global_scb.fnum == fnum_max)
- global_scb.rmfile = 1;
- if (open_oldoutfile(global_scb.fnum, 0,
- global_scb.rmfile) < 0) {
+ if (switch_oldoutfile(0, &global_scb) < 0) {
perr("Couldn't open file, exiting.");
return -1;
}
@@ -343,6 +383,19 @@ int write_realtime_data(void *data, ssize_t nb)
return bw != nb;
}
+static void switchfile_handler(int sig)
+{
+ int i;
+ dbug(3, "file switching signal %d received\n", sig);
+ for (i = 0; i < ncpus; i++) {
+ if (reader[i]) {
+ switch_file[i] = 1;
+ pthread_kill(reader[i], SIGUSR2);
+ } else
+ break;
+ }
+}
+
/**
* init_relayfs - create files and threads for relayfs processing
*
@@ -353,6 +406,12 @@ int init_oldrelayfs(void)
int i, j;
struct statfs st;
char relay_filebase[PATH_MAX], proc_filebase[PATH_MAX];
+ struct sigaction sa;
+
+ sa.sa_handler = switchfile_handler;
+ sa.sa_flags = 0;
+ sigemptyset(&sa.sa_mask);
+ sigaction(SIGUSR1, &sa, NULL);
dbug(2, "initializing relayfs.n_subbufs=%d subbuf_size=%d\n", n_subbufs, subbuf_size);
--
Masami Hiramatsu
Software Engineer
Hitachi Computer Products (America), Inc.
Software Solutions Division
e-mail: mhiramat@redhat.com
next prev parent reply other threads:[~2009-09-09 16:33 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-09-09 16:32 [PATCH 0/3] Signal-based file switching support Masami Hiramatsu
2009-09-09 16:33 ` Masami Hiramatsu [this message]
2009-09-09 16:33 ` [PATCH 3/3] Add signal based file switching testcase Masami Hiramatsu
2009-09-09 16:33 ` [PATCH 1/3] Signal-based file switching support for relay/ring buffer Masami Hiramatsu
2009-09-12 0:48 ` [PATCH 0/3] Signal-based file switching support Masami Hiramatsu
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