Android 11 init过程中日志丢失

增加kernel log缓存和输出频率

diff --git a/kernel/include/linux/ratelimit.h b/kernel/linux-4.9.y/include/linux/ratelimit.h
index 57c9e0622..d8cc7dba9 100644
--- a/kernel/include/linux/ratelimit.h
+++ b/kernel/include/linux/ratelimit.h
@@ -6,7 +6,7 @@
 #include <linux/spinlock.h>
 
 #define DEFAULT_RATELIMIT_INTERVAL     (5 * HZ)
-#define DEFAULT_RATELIMIT_BURST                10
+#define DEFAULT_RATELIMIT_BURST                100000
 
 /* issue num suppressed message on exit */
 #define RATELIMIT_MSG_ON_RELEASE       BIT(0)
diff --git a/kernel/kernel/printk/printk.c b/kernel/kernel/printk/printk.c
index 20fc294fb..9701e0f5a 100644
--- a/kernel/kernel/printk/printk.c
+++ b/kernel/kernel/printk/printk.c
@@ -388,7 +388,7 @@ static u32 clear_idx;
 
 /* record buffer */
 #define LOG_ALIGN __alignof__(struct printk_log)
-#define __LOG_BUF_LEN (1 << CONFIG_LOG_BUF_SHIFT)
+#define __LOG_BUF_LEN ( 4*1024 *1024 )
+#define LOG_BUF_LEN_MAX (4*1024 *1024)
 static char __log_buf[__LOG_BUF_LEN] __aligned(LOG_ALIGN);
 static char *log_buf = __log_buf;
 static u32 log_buf_len = __LOG_BUF_LEN;