diff options
| -rw-r--r-- | docs/busybox.sgml | 34 | ||||
| -rw-r--r-- | include/usage.h | 8 | ||||
| -rw-r--r-- | sysklogd/Config.in | 19 | ||||
| -rw-r--r-- | sysklogd/logread.c | 7 | ||||
| -rw-r--r-- | sysklogd/syslogd.c | 14 |
5 files changed, 70 insertions, 12 deletions
diff --git a/docs/busybox.sgml b/docs/busybox.sgml index 1d2e9268a..ac400c7c8 100644 --- a/docs/busybox.sgml +++ b/docs/busybox.sgml @@ -1976,6 +1976,38 @@ </para> </sect1> + <sect1 id="logread"> + <title>logread</title> + + <para> + Usage: logread [OPTION]... + </para> + + <para> + Shows the messages from syslogd (using circular buffer). + </para> + + <para> + Options: + </para> + + <para> + <screen> + -f Output data as the log grows. + </screen> + </para> + + <para> + Example: + </para> + + <para> + <screen> + $ logread + </screen> + </para> + </sect1> + <sect1 id="ls"> <title>ls</title> @@ -3110,7 +3142,7 @@ -O FILE Use an alternate log file (default=/var/log/messages) -R HOST[:PORT] Log remotely to IP or hostname on PORT (default PORT=514/UDP) -L Log locally as well as network logging (default is network only) - -C Log to a circular buffer. Read this buffer using 'logread' + -C [size(KiB)] Log to a circular buffer. Read this buffer using 'logread' </screen> </para> diff --git a/include/usage.h b/include/usage.h index 6db0385fb..ea1b5d5fe 100644 --- a/include/usage.h +++ b/include/usage.h @@ -1458,10 +1458,12 @@ "root\n" #define logread_trivial_usage \ - "" + "[OPTION]..." #define logread_full_usage \ - "Shows the messages from syslogd (using circular buffer)." + "Shows the messages from syslogd (using circular buffer).\n\n" + "Options:\n" \ + "\t-f\t\toutput data as the log grows" #define losetup_trivial_usage \ "[OPTION]... LOOPDEVICE FILE\n" \ @@ -2280,7 +2282,7 @@ "\n\t-R HOST[:PORT]\tLog to IP or hostname on PORT (default PORT=514/UDP)\n" \ "\t-L\t\tLog locally and via network logging (default is network only)") \ USAGE_IPC_LOG( \ - "\n\t-C\t\tLog to a circular buffer (read the buffer using logread)") + "\n\t-C [size(KiB)]\tLog to a circular buffer (read the buffer using logread)") #define syslogd_example_usage \ "$ syslogd -R masterlog:514\n" \ "$ syslogd -R 192.168.1.1:601\n" diff --git a/sysklogd/Config.in b/sysklogd/Config.in index cb2ee0865..a671f59f1 100644 --- a/sysklogd/Config.in +++ b/sysklogd/Config.in @@ -56,6 +56,14 @@ config CONFIG_FEATURE_IPC_SYSLOG entire filesystem, which may cause your system to break badly. +config CONFIG_FEATURE_IPC_SYSLOG_BUFFER_SIZE + int " Circular buffer size in Kbytes (minimum 4KB)" + default 16 + depends on CONFIG_FEATURE_IPC_SYSLOG + help + This option sets the size of the circular buffer + used to record system log messages. + config CONFIG_LOGREAD bool " logread" default y @@ -66,6 +74,17 @@ config CONFIG_LOGREAD utility will allow you to read the messages that are stored in the syslogd circular buffer. +config CONFIG_FEATURE_LOGREAD_REDUCED_LOCKING + bool " logread double buffering" + default n + depends on CONFIG_LOGREAD + help + 'logread' ouput to slow serial terminals can have + side effects on syslog because of the semaphore. + This option make logread to double buffer copy + from circular buffer, minimizing semaphore + contention at some minor memory expense. + config CONFIG_KLOGD bool "klogd" default n diff --git a/sysklogd/logread.c b/sysklogd/logread.c index 524178fe8..207e78b57 100644 --- a/sysklogd/logread.c +++ b/sysklogd/logread.c @@ -108,8 +108,7 @@ extern int logread_main(int argc, char **argv) i = follow ? buf->tail : buf->head; do { -#undef RC_LOGREAD -#ifdef RC_LOGREAD +#ifdef CONFIG_FEATURE_LOGREAD_REDUCED_LOCKING char *buf_data; int log_len,j; #endif @@ -128,7 +127,7 @@ extern int logread_main(int argc, char **argv) } // Read Memory -#ifdef RC_LOGREAD +#ifdef CONFIG_FEATURE_LOGREAD_REDUCED_LOCKING log_len = buf->tail - i; if (log_len < 0) log_len += buf->size; @@ -155,7 +154,7 @@ extern int logread_main(int argc, char **argv) // release the lock on the log chain sem_up(log_semid); -#ifdef RC_LOGREAD +#ifdef CONFIG_FEATURE_LOGREAD_REDUCED_LOCKING for (j=0; j < log_len; j+=strlen(buf_data+j)+1) { printf("%s", buf_data+j); if (follow) diff --git a/sysklogd/syslogd.c b/sysklogd/syslogd.c index 622500e48..42426ed80 100644 --- a/sysklogd/syslogd.c +++ b/sysklogd/syslogd.c @@ -94,6 +94,12 @@ static int local_logging = FALSE; /* circular buffer variables/structures */ #ifdef CONFIG_FEATURE_IPC_SYSLOG + +#if CONFIG_FEATURE_IPC_SYSLOG_BUFFER_SIZE < 4 +#error Sorry, you must set the syslogd buffer size to at least 4KB. +#error Please check CONFIG_FEATURE_IPC_SYSLOG_BUFFER_SIZE +#endif + #include <sys/ipc.h> #include <sys/sem.h> #include <sys/shm.h> @@ -114,7 +120,7 @@ static struct sembuf SMwdn[3] = { {0, 0}, {1, 0}, {1, +1} }; // set SMwdn static int shmid = -1; // ipc shared memory id static int s_semid = -1; // ipc semaphore id -static int data_size = 16000; // default data size +static int shm_size = ((CONFIG_FEATURE_IPC_SYSLOG_BUFFER_SIZE)*1024); // default shm size static int circular_logging = FALSE; /* @@ -156,7 +162,7 @@ void ipcsyslog_cleanup(void) void ipcsyslog_init(void) { if (buf == NULL) { - if ((shmid = shmget(KEY_ID, data_size, IPC_CREAT | 1023)) == -1) { + if ((shmid = shmget(KEY_ID, shm_size, IPC_CREAT | 1023)) == -1) { bb_perror_msg_and_die("shmget"); } @@ -164,7 +170,7 @@ void ipcsyslog_init(void) bb_perror_msg_and_die("shmat"); } - buf->size = data_size - sizeof(*buf); + buf->size = shm_size - sizeof(*buf); buf->head = buf->tail = 0; // we'll trust the OS to set initial semval to 0 (let's hope) @@ -654,7 +660,7 @@ extern int syslogd_main(int argc, char **argv) if (optarg) { int buf_size = atoi(optarg); if (buf_size >= 4) { - data_size = buf_size; + shm_size = buf_size; } } circular_logging = TRUE; |