From 8446f1d391f3d27e6bf9c43d4cbcdac0ca720417 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Tue, 6 Sep 2005 15:16:27 -0700 Subject: [PATCH] detect soft lockups This patch adds a new kernel debug feature: CONFIG_DETECT_SOFTLOCKUP. When enabled then per-CPU watchdog threads are started, which try to run once per second. If they get delayed for more than 10 seconds then a callback from the timer interrupt detects this condition and prints out a warning message and a stack dump (once per lockup incident). The feature is otherwise non-intrusive, it doesnt try to unlock the box in any way, it only gets the debug info out, automatically, and on all CPUs affected by the lockup. Signed-off-by: Ingo Molnar Signed-off-by: Nishanth Aravamudan Signed-Off-By: Matthias Urlichs Signed-off-by: Richard Purdie Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- init/main.c | 1 + 1 file changed, 1 insertion(+) (limited to 'init/main.c') diff --git a/init/main.c b/init/main.c index ff410063e4e1..a29fb2ac7240 100644 --- a/init/main.c +++ b/init/main.c @@ -614,6 +614,7 @@ static void do_pre_smp_initcalls(void) migration_init(); #endif spawn_ksoftirqd(); + spawn_softlockup_task(); } static void run_init_process(char *init_filename) -- cgit v1.2.2 From c1d7ef70a71eb54fb389a9a411d331661be73056 Mon Sep 17 00:00:00 2001 From: "Avery, Brian" Date: Tue, 6 Sep 2005 15:16:56 -0700 Subject: [PATCH] Add warning `init=' to init/main.c I passed init=/mylinuxrc to the kernel on the command line. The kernel silently dropped down to exec /sbin/init. It turned out that /mylinuxrc had improper permissions. Without any warning message from the kernel that something was wrong it took awhile to find the issue. The patch below adds a warning. Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- init/main.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'init/main.c') diff --git a/init/main.c b/init/main.c index a29fb2ac7240..e4dbcbcd26cf 100644 --- a/init/main.c +++ b/init/main.c @@ -708,10 +708,11 @@ static int init(void * unused) * The Bourne shell can be used instead of init if we are * trying to recover a really broken machine. */ - - if (execute_command) + if (execute_command) { run_init_process(execute_command); - + printk(KERN_WARNING "Failed to execute %s. Attempting " + "defaults...\n", execute_command); + } run_init_process("/sbin/init"); run_init_process("/etc/init"); run_init_process("/bin/init"); -- cgit v1.2.2 From ffdfc40976dda18d923cd001d44bf0ee55da1af4 Mon Sep 17 00:00:00 2001 From: Olof Johansson Date: Tue, 6 Sep 2005 15:17:19 -0700 Subject: [PATCH] Add rdinit parameter to pick early userspace init Since early userspace was added, there's no way to override which init to run from it. Some people tack on an extra cpio archive with a link from /init depending on what they want to run, but that's sometimes impractical. Changing the "init=" to also override the early userspace isn't feasible, since it is still used to indicate what init to run from disk when early userspace has completed doing whatever it's doing (i.e. load filesystem modules and drivers). Instead, introduce "rdinit=" and make it override the default "/init" if specified. Signed-off-by: Olof Johansson Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- init/main.c | 31 +++++++++++++++++++++++++++---- 1 file changed, 27 insertions(+), 4 deletions(-) (limited to 'init/main.c') diff --git a/init/main.c b/init/main.c index e4dbcbcd26cf..f142d4035341 100644 --- a/init/main.c +++ b/init/main.c @@ -123,6 +123,7 @@ extern void softirq_init(void); char saved_command_line[COMMAND_LINE_SIZE]; static char *execute_command; +static char *ramdisk_execute_command; /* Setup configured maximum number of CPUs to activate */ static unsigned int max_cpus = NR_CPUS; @@ -297,6 +298,18 @@ static int __init init_setup(char *str) } __setup("init=", init_setup); +static int __init rdinit_setup(char *str) +{ + unsigned int i; + + ramdisk_execute_command = str; + /* See "auto" comment in init_setup */ + for (i = 1; i < MAX_INIT_ARGS; i++) + argv_init[i] = NULL; + return 1; +} +__setup("rdinit=", rdinit_setup); + extern void setup_arch(char **); #ifndef CONFIG_SMP @@ -681,10 +694,14 @@ static int init(void * unused) * check if there is an early userspace init. If yes, let it do all * the work */ - if (sys_access((const char __user *) "/init", 0) == 0) - execute_command = "/init"; - else + + if (!ramdisk_execute_command) + ramdisk_execute_command = "/init"; + + if (sys_access((const char __user *) ramdisk_execute_command, 0) != 0) { + ramdisk_execute_command = NULL; prepare_namespace(); + } /* * Ok, we have completed the initial bootup, and @@ -701,7 +718,13 @@ static int init(void * unused) (void) sys_dup(0); (void) sys_dup(0); - + + if (ramdisk_execute_command) { + run_init_process(ramdisk_execute_command); + printk(KERN_WARNING "Failed to execute %s\n", + ramdisk_execute_command); + } + /* * We try each of these until one succeeds. * -- cgit v1.2.2