1 files changed, 18 insertions, 0 deletions

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 396c38b3cb69..7d16e6433302 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -413,6 +413,24 @@ config FORCED_INLINING
           become the default in the future, until then this option is there to
           test gcc for this.
 
+config BOOT_PRINTK_DELAY
+        bool "Delay each boot printk message by N milliseconds"
+        depends on DEBUG_KERNEL && PRINTK && GENERIC_CALIBRATE_DELAY
+        help
+          This build option allows you to read kernel boot messages
+          by inserting a short delay after each one.  The delay is
+          specified in milliseconds on the kernel command line,
+          using "boot_delay=N".
+
+          It is likely that you would also need to use "lpj=M" to preset
+          the "loops per jiffie" value.
+          See a previous boot log for the "lpj" value to use for your
+          system, and then set "lpj=M" before setting "boot_delay=N".
+          NOTE:  Using this option may adversely affect SMP systems.
+          I.e., processors other than the first one may not boot up.
+          BOOT_PRINTK_DELAY also may cause DETECT_SOFTLOCKUP to detect
+          what it believes to be lockup conditions.
+
 config RCU_TORTURE_TEST
         tristate "torture tests for RCU"
         depends on DEBUG_KERNEL