Support variable sized subbuffers

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>

diff --git a/configure.in b/configure.in
index 82cc2c30cd46f079dfe6987f4c0b449ed1cd6628..173bef82f1c7c8df3ede01d84e228783e8dc6a40 100644 (file)
--- a/configure.in
+++ b/configure.in
@@ -23,7 +23,7 @@
 AC_PREREQ(2.57)
 AC_INIT(FULL-PACKAGE-NAME, VERSION, BUG-REPORT-ADDRESS)
 #AC_WITH_LTDL  # not needed ?
-AM_INIT_AUTOMAKE(ltt-control,0.75-15112009)
+AM_INIT_AUTOMAKE(ltt-control,0.76-16112009)
 AM_CONFIG_HEADER(config.h)
 AM_PROG_LIBTOOL
 

diff --git a/lttd/lttd.c b/lttd/lttd.c
index b2e7127833141da0f66515918f73af51444398d1..773cb234108350df3ac15ef1b5f1e4e7e5f97c22 100644 (file)
--- a/lttd/lttd.c
+++ b/lttd/lttd.c
@@ -42,13 +42,16 @@
 #include <asm/types.h>
 
 /* Get the next sub buffer that can be read. */
-#define RELAY_GET_SUBBUF        _IOR(0xF5, 0x00,__u32)
+#define RELAY_GET_SB           _IOR(0xF5, 0x00,__u32)
 /* Release the oldest reserved (by "get") sub buffer. */
-#define RELAY_PUT_SUBBUF        _IOW(0xF5, 0x01,__u32)
+#define RELAY_PUT_SB           _IOW(0xF5, 0x01,__u32)
 /* returns the number of sub buffers in the per cpu channel. */
-#define RELAY_GET_N_SUBBUFS     _IOR(0xF5, 0x02,__u32)
-/* returns the size of the sub buffers. */
-#define RELAY_GET_SUBBUF_SIZE   _IOR(0xF5, 0x03,__u32)
+#define RELAY_GET_N_SB         _IOR(0xF5, 0x02,__u32)
+/* returns the size of the current sub buffer. */
+#define RELAY_GET_SB_SIZE      _IOR(0xF5, 0x03, __u32)
+/* returns the size of data to consume in the current sub-buffer. */
+#define RELAY_GET_MAX_SB_SIZE  _IOR(0xF5, 0x04, __u32)
+
 
 #if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,14)
 #include <sys/inotify.h>
@@ -88,18 +91,11 @@ static inline int inotify_rm_watch (int fd, __u32 wd)
 #undef HAS_INOTIFY
 #endif
 
-enum {
-       GET_SUBBUF,
-       PUT_SUBBUF,
-       GET_N_BUBBUFS,
-       GET_SUBBUF_SIZE
-};
-
 struct fd_pair {
        int channel;
        int trace;
-       unsigned int n_subbufs;
-       unsigned int subbuf_size;
+       unsigned int n_sb;
+       unsigned int max_sb_size;
        void *mmap;
        pthread_mutex_t mutex;
 };
@@ -455,14 +451,13 @@ end:
 
 int read_subbuffer(struct fd_pair *pair)
 {
-       unsigned int consumed_old;
+       unsigned int consumed_old, len;
        int err;
        long ret;
-       unsigned long len;
        off_t offset;
 
 
-       err = ioctl(pair->channel, RELAY_GET_SUBBUF, &consumed_old);
+       err = ioctl(pair->channel, RELAY_GET_SB, &consumed_old);
        printf_verbose("cookie : %u\n", consumed_old);
        if(err != 0) {
                ret = errno;
@@ -481,7 +476,13 @@ int read_subbuffer(struct fd_pair *pair)
                goto write_error;
        }
 #endif //0
-       len = pair->subbuf_size;
+       err = ioctl(pair->channel, RELAY_GET_SB_SIZE, &len);
+       if(err != 0) {
+               ret = errno;
+               perror("Getting sub-buffer len failed.");
+               goto get_error;
+       }
+
        offset = 0;
        while (len > 0) {
                printf_verbose("splice chan to pipe offset %lu\n",
@@ -513,14 +514,14 @@ int read_subbuffer(struct fd_pair *pair)
 #endif //0
 write_error:
        ret = 0;
-       err = ioctl(pair->channel, RELAY_PUT_SUBBUF, &consumed_old);
+       err = ioctl(pair->channel, RELAY_PUT_SB, &consumed_old);
        if(err != 0) {
                ret = errno;
                if(errno == EFAULT) {
                        perror("Error in unreserving sub buffer\n");
                } else if(errno == EIO) {
-                       perror("Reader has been pushed by the writer, last subbuffer corrupted.");
-                       /* FIXME : we may delete the last written buffer if we wish. */
+                       /* Should never happen with newer LTTng versions */
+                       perror("Reader has been pushed by the writer, last sub-buffer corrupted.");
                }
                goto get_error;
        }
@@ -546,16 +547,15 @@ int map_channels(struct channel_trace_fd *fd_pairs,
        for(i=idx_begin;i<idx_end;i++) {
                struct fd_pair *pair = &fd_pairs->pair[i];
 
-               ret = ioctl(pair->channel, RELAY_GET_N_SUBBUFS, 
-                                                       &pair->n_subbufs);
+               ret = ioctl(pair->channel, RELAY_GET_N_SB, &pair->n_sb);
                if(ret != 0) {
-                       perror("Error in getting the number of subbuffers");
+                       perror("Error in getting the number of sub-buffers");
                        goto end;
                }
-               ret = ioctl(pair->channel, RELAY_GET_SUBBUF_SIZE, 
-                                                       &pair->subbuf_size);
+               ret = ioctl(pair->channel, RELAY_GET_MAX_SB_SIZE, 
+                           &pair->max_sb_size);
                if(ret != 0) {
-                       perror("Error in getting the size of the subbuffers");
+                       perror("Error in getting the max sub-buffer size");
                        goto end;
                }
                ret = pthread_mutex_init(&pair->mutex, NULL);   /* Fast mutex */
@@ -824,7 +824,7 @@ int read_channels(unsigned long thread_num, struct channel_trace_fd *fd_pairs,
                                                        pollfd[i].fd);
                                                /* Take care of high priority channels first. */
                                                high_prio = 1;
-                                               /* it's ok to have an unavailable subbuffer */
+                                               /* it's ok to have an unavailable sub-buffer */
                                                ret = read_subbuffer(&fd_pairs->pair[i-inotify_fds]);
                                                if(ret == EAGAIN) ret = 0;