From: Denys Vlasenko Stop using unsigned _longs_ for printk buffer indexes. Log buffer is way smaller than 2 gigabytes and unsigned ints will work too . Indeed, they do work nicely on all 32-bit platforms where longs and ints are the same. With this patch, we have following size savings on amd64: text data bss dec hex filename 5997 313 17736 24046 5dee 2.6.23.1.t64/kernel/printk.o 5858 313 17700 23871 5d3f 2.6.23.1.printk.t64/kernel/printk.o Signed-off-by: Denys Vlasenko Signed-off-by: Andrew Morton --- kernel/printk.c | 36 ++++++++++++++++++------------------ 1 file changed, 18 insertions(+), 18 deletions(-) diff -puN kernel/printk.c~printkc-use-ints-instead-of-longs-for-logbuf-index kernel/printk.c --- a/kernel/printk.c~printkc-use-ints-instead-of-longs-for-logbuf-index +++ a/kernel/printk.c @@ -86,16 +86,16 @@ static int console_locked, console_suspe */ static DEFINE_SPINLOCK(logbuf_lock); -#define LOG_BUF_MASK (log_buf_len-1) +#define LOG_BUF_MASK (log_buf_len-1) #define LOG_BUF(idx) (log_buf[(idx) & LOG_BUF_MASK]) /* * The indices into log_buf are not constrained to log_buf_len - they * must be masked before subscripting */ -static unsigned long log_start; /* Index into log_buf: next char to be read by syslog() */ -static unsigned long con_start; /* Index into log_buf: next char to be sent to consoles */ -static unsigned long log_end; /* Index into log_buf: most-recently-written-char + 1 */ +static unsigned log_start; /* Index into log_buf: next char to be read by syslog() */ +static unsigned con_start; /* Index into log_buf: next char to be sent to consoles */ +static unsigned log_end; /* Index into log_buf: most-recently-written-char + 1 */ /* * Array of consoles built from command line options (console=) @@ -121,17 +121,17 @@ static int console_may_schedule; static char __log_buf[__LOG_BUF_LEN]; static char *log_buf = __log_buf; static int log_buf_len = __LOG_BUF_LEN; -static unsigned long logged_chars; /* Number of chars produced since last read+clear operation */ +static unsigned logged_chars; /* Number of chars produced since last read+clear operation */ static int __init log_buf_len_setup(char *str) { - unsigned long size = memparse(str, &str); + unsigned size = memparse(str, &str); unsigned long flags; if (size) size = roundup_pow_of_two(size); if (size > log_buf_len) { - unsigned long start, dest_idx, offset; + unsigned start, dest_idx, offset; char *new_log_buf; new_log_buf = alloc_bootmem(size); @@ -288,7 +288,7 @@ int log_buf_read(int idx) */ int do_syslog(int type, char __user *buf, int len) { - unsigned long i, j, limit, count; + unsigned i, j, limit, count; int do_clear = 0; char c; int error = 0; @@ -429,7 +429,7 @@ asmlinkage long sys_syslog(int type, cha /* * Call the console drivers on a range of log_buf */ -static void __call_console_drivers(unsigned long start, unsigned long end) +static void __call_console_drivers(unsigned start, unsigned end) { struct console *con; @@ -456,8 +456,8 @@ __setup("ignore_loglevel", ignore_loglev /* * Write out chars from start to end - 1 inclusive */ -static void _call_console_drivers(unsigned long start, - unsigned long end, int msg_log_level) +static void _call_console_drivers(unsigned start, + unsigned end, int msg_log_level) { if ((msg_log_level < console_loglevel || ignore_loglevel) && console_drivers && start != end) { @@ -477,12 +477,12 @@ static void _call_console_drivers(unsign * log_buf[start] to log_buf[end - 1]. * The console_sem must be held. */ -static void call_console_drivers(unsigned long start, unsigned long end) +static void call_console_drivers(unsigned start, unsigned end) { - unsigned long cur_index, start_print; + unsigned cur_index, start_print; static int msg_level = -1; - BUG_ON(((long)(start - end)) > 0); + BUG_ON(((int)(start - end)) > 0); cur_index = start; start_print = start; @@ -760,7 +760,7 @@ asmlinkage long sys_syslog(int type, cha return -ENOSYS; } -static void call_console_drivers(unsigned long start, unsigned long end) +static void call_console_drivers(unsigned start, unsigned end) { } @@ -953,8 +953,8 @@ void wake_up_klogd(void) void release_console_sem(void) { unsigned long flags; - unsigned long _con_start, _log_end; - unsigned long wake_klogd = 0; + unsigned _con_start, _log_end; + unsigned wake_klogd = 0; if (console_suspended) { up(&secondary_console_sem); @@ -1245,7 +1245,7 @@ void tty_write_message(struct tty_struct int __printk_ratelimit(int ratelimit_jiffies, int ratelimit_burst) { static DEFINE_SPINLOCK(ratelimit_lock); - static unsigned long toks = 10 * 5 * HZ; + static unsigned toks = 10 * 5 * HZ; static unsigned long last_msg; static int missed; unsigned long flags; _