From 7e96287ddc4f42081e18248b6167041c0908004c Mon Sep 17 00:00:00 2001 From: Vivek Goyal Date: Wed, 27 Sep 2006 01:50:44 -0700 Subject: [PATCH] kdump: introduce "reset_devices" command line option Resetting the devices during driver initialization can be a costly operation in terms of time (especially scsi devices). This option can be used by drivers to know that user forcibly wants the devices to be reset during initialization. This option can be useful while kernel is booting in unreliable environment. For ex. during kdump boot where devices are in unknown random state and BIOS execution has been skipped. Signed-off-by: Vivek Goyal Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/init.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/init.h') diff --git a/include/linux/init.h b/include/linux/init.h index 6667785dd1ff..e92b1455d7af 100644 --- a/include/linux/init.h +++ b/include/linux/init.h @@ -68,6 +68,7 @@ extern initcall_t __security_initcall_start[], __security_initcall_end[]; /* Defined in init/main.c */ extern char saved_command_line[]; +extern unsigned int reset_devices; /* used by init/main.c */ extern void setup_arch(char **); -- cgit v1.2.3 From 735a7ffb739b6efeaeb1e720306ba308eaaeb20e Mon Sep 17 00:00:00 2001 From: Andrew Morton Date: Fri, 27 Oct 2006 11:42:37 -0700 Subject: [PATCH] drivers: wait for threaded probes between initcall levels The multithreaded-probing code has a problem: after one initcall level (eg, core_initcall) has been processed, we will then start processing the next level (postcore_initcall) while the kernel threads which are handling core_initcall are still executing. This breaks the guarantees which the layered initcalls previously gave us. IOW, we want to be multithreaded _within_ an initcall level, but not between different levels. Fix that up by causing the probing code to wait for all outstanding probes at one level to complete before we start processing the next level. Cc: Greg KH Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/base/dd.c | 30 ++++++++++++++++++++++++++++++ include/asm-generic/vmlinux.lds.h | 9 ++++++++- include/linux/init.h | 28 +++++++++++++++++++--------- 3 files changed, 57 insertions(+), 10 deletions(-) (limited to 'include/linux/init.h') diff --git a/drivers/base/dd.c b/drivers/base/dd.c index db01b95a47a5..c5d6bb4290ad 100644 --- a/drivers/base/dd.c +++ b/drivers/base/dd.c @@ -18,6 +18,7 @@ #include #include #include +#include #include "base.h" #include "power/power.h" @@ -70,6 +71,8 @@ struct stupid_thread_structure { }; static atomic_t probe_count = ATOMIC_INIT(0); +static DECLARE_WAIT_QUEUE_HEAD(probe_waitqueue); + static int really_probe(void *void_data) { struct stupid_thread_structure *data = void_data; @@ -121,6 +124,7 @@ probe_failed: done: kfree(data); atomic_dec(&probe_count); + wake_up(&probe_waitqueue); return ret; } @@ -337,6 +341,32 @@ void driver_detach(struct device_driver * drv) } } +#ifdef CONFIG_PCI_MULTITHREAD_PROBE +static int __init wait_for_probes(void) +{ + DEFINE_WAIT(wait); + + printk(KERN_INFO "%s: waiting for %d threads\n", __FUNCTION__, + atomic_read(&probe_count)); + if (!atomic_read(&probe_count)) + return 0; + while (atomic_read(&probe_count)) { + prepare_to_wait(&probe_waitqueue, &wait, TASK_UNINTERRUPTIBLE); + if (atomic_read(&probe_count)) + schedule(); + } + finish_wait(&probe_waitqueue, &wait); + return 0; +} + +core_initcall_sync(wait_for_probes); +postcore_initcall_sync(wait_for_probes); +arch_initcall_sync(wait_for_probes); +subsys_initcall_sync(wait_for_probes); +fs_initcall_sync(wait_for_probes); +device_initcall_sync(wait_for_probes); +late_initcall_sync(wait_for_probes); +#endif EXPORT_SYMBOL_GPL(device_bind_driver); EXPORT_SYMBOL_GPL(device_release_driver); diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index e3e83bcaf710..9d873163a7ab 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -216,10 +216,17 @@ #define INITCALLS \ *(.initcall1.init) \ + *(.initcall1s.init) \ *(.initcall2.init) \ + *(.initcall2s.init) \ *(.initcall3.init) \ + *(.initcall3s.init) \ *(.initcall4.init) \ + *(.initcall4s.init) \ *(.initcall5.init) \ + *(.initcall5s.init) \ *(.initcall6.init) \ - *(.initcall7.init) + *(.initcall6s.init) \ + *(.initcall7.init) \ + *(.initcall7s.init) diff --git a/include/linux/init.h b/include/linux/init.h index e92b1455d7af..ff40ea118e3a 100644 --- a/include/linux/init.h +++ b/include/linux/init.h @@ -84,19 +84,29 @@ extern void setup_arch(char **); * by link order. * For backwards compatibility, initcall() puts the call in * the device init subsection. + * + * The `id' arg to __define_initcall() is needed so that multiple initcalls + * can point at the same handler without causing duplicate-symbol build errors. */ -#define __define_initcall(level,fn) \ - static initcall_t __initcall_##fn __attribute_used__ \ +#define __define_initcall(level,fn,id) \ + static initcall_t __initcall_##fn##id __attribute_used__ \ __attribute__((__section__(".initcall" level ".init"))) = fn -#define core_initcall(fn) __define_initcall("1",fn) -#define postcore_initcall(fn) __define_initcall("2",fn) -#define arch_initcall(fn) __define_initcall("3",fn) -#define subsys_initcall(fn) __define_initcall("4",fn) -#define fs_initcall(fn) __define_initcall("5",fn) -#define device_initcall(fn) __define_initcall("6",fn) -#define late_initcall(fn) __define_initcall("7",fn) +#define core_initcall(fn) __define_initcall("1",fn,1) +#define core_initcall_sync(fn) __define_initcall("1s",fn,1s) +#define postcore_initcall(fn) __define_initcall("2",fn,2) +#define postcore_initcall_sync(fn) __define_initcall("2s",fn,2s) +#define arch_initcall(fn) __define_initcall("3",fn,3) +#define arch_initcall_sync(fn) __define_initcall("3s",fn,3s) +#define subsys_initcall(fn) __define_initcall("4",fn,4) +#define subsys_initcall_sync(fn) __define_initcall("4s",fn,4s) +#define fs_initcall(fn) __define_initcall("5",fn,5) +#define fs_initcall_sync(fn) __define_initcall("5s",fn,5s) +#define device_initcall(fn) __define_initcall("6",fn,6) +#define device_initcall_sync(fn) __define_initcall("6s",fn,6s) +#define late_initcall(fn) __define_initcall("7",fn,7) +#define late_initcall_sync(fn) __define_initcall("7s",fn,7s) #define __initcall(fn) device_initcall(fn) -- cgit v1.2.3 From b3438f8266cb1f5010085ac47d7ad6a36a212164 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Mon, 20 Nov 2006 11:47:18 -0800 Subject: Add "pure_initcall" for static variable initialization This is a quick hack to overcome the fact that SRCU currently does not allow static initializers, and we need to sometimes initialize those things before any other initializers (even "core" ones) can do so. Currently we don't allow this at all for modules, and the only user that needs is right now is cpufreq. As reported by Thomas Gleixner: "Commit b4dfdbb3c707474a2254c5b4d7e62be31a4b7da9 ("[PATCH] cpufreq: make the transition_notifier chain use SRCU breaks cpu frequency notification users, which register the callback > on core_init level." Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Arjan van de Ven Cc: Andrew Morton , Signed-off-by: Linus Torvalds --- drivers/cpufreq/cpufreq.c | 2 +- include/asm-generic/vmlinux.lds.h | 2 ++ include/linux/init.h | 8 ++++++++ 3 files changed, 11 insertions(+), 1 deletion(-) (limited to 'include/linux/init.h') diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index 86e69b7f9122..dd0c2623e27b 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -59,7 +59,7 @@ static int __init init_cpufreq_transition_notifier_list(void) srcu_init_notifier_head(&cpufreq_transition_notifier_list); return 0; } -core_initcall(init_cpufreq_transition_notifier_list); +pure_initcall(init_cpufreq_transition_notifier_list); static LIST_HEAD(cpufreq_governor_list); static DEFINE_MUTEX (cpufreq_governor_mutex); diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index 9d873163a7ab..e60d6f21fa62 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -215,6 +215,8 @@ .notes : { *(.note.*) } :note #define INITCALLS \ + *(.initcall0.init) \ + *(.initcall0s.init) \ *(.initcall1.init) \ *(.initcall1s.init) \ *(.initcall2.init) \ diff --git a/include/linux/init.h b/include/linux/init.h index ff40ea118e3a..5eb5d24b7680 100644 --- a/include/linux/init.h +++ b/include/linux/init.h @@ -93,6 +93,14 @@ extern void setup_arch(char **); static initcall_t __initcall_##fn##id __attribute_used__ \ __attribute__((__section__(".initcall" level ".init"))) = fn +/* + * A "pure" initcall has no dependencies on anything else, and purely + * initializes variables that couldn't be statically initialized. + * + * This only exists for built-in code, not for modules. + */ +#define pure_initcall(fn) __define_initcall("0",fn,1) + #define core_initcall(fn) __define_initcall("1",fn,1) #define core_initcall_sync(fn) __define_initcall("1s",fn,1s) #define postcore_initcall(fn) __define_initcall("2",fn,2) -- cgit v1.2.3 From 8d610dd52dd1da696e199e4b4545f33a2a5de5c6 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Mon, 11 Dec 2006 12:12:04 -0800 Subject: Make sure we populate the initroot filesystem late enough We should not initialize rootfs before all the core initializers have run. So do it as a separate stage just before starting the regular driver initializers. Signed-off-by: Linus Torvalds --- include/asm-generic/vmlinux.lds.h | 1 + include/linux/init.h | 1 + init/initramfs.c | 6 ++++-- init/main.c | 7 ------- 4 files changed, 6 insertions(+), 9 deletions(-) (limited to 'include/linux/init.h') diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index 6e9fcebbf89f..7437ccaada77 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -242,6 +242,7 @@ *(.initcall4s.init) \ *(.initcall5.init) \ *(.initcall5s.init) \ + *(.initcallrootfs.init) \ *(.initcall6.init) \ *(.initcall6s.init) \ *(.initcall7.init) \ diff --git a/include/linux/init.h b/include/linux/init.h index 5eb5d24b7680..5a593a1dec1e 100644 --- a/include/linux/init.h +++ b/include/linux/init.h @@ -111,6 +111,7 @@ extern void setup_arch(char **); #define subsys_initcall_sync(fn) __define_initcall("4s",fn,4s) #define fs_initcall(fn) __define_initcall("5",fn,5) #define fs_initcall_sync(fn) __define_initcall("5s",fn,5s) +#define rootfs_initcall(fn) __define_initcall("rootfs",fn,rootfs) #define device_initcall(fn) __define_initcall("6",fn,6) #define device_initcall_sync(fn) __define_initcall("6s",fn,6s) #define late_initcall(fn) __define_initcall("7",fn,7) diff --git a/init/initramfs.c b/init/initramfs.c index 85f04037ade1..4fa0f7977de1 100644 --- a/init/initramfs.c +++ b/init/initramfs.c @@ -526,7 +526,7 @@ static void __init free_initrd(void) #endif -void __init populate_rootfs(void) +static int __init populate_rootfs(void) { char *err = unpack_to_rootfs(__initramfs_start, __initramfs_end - __initramfs_start, 0); @@ -544,7 +544,7 @@ void __init populate_rootfs(void) unpack_to_rootfs((char *)initrd_start, initrd_end - initrd_start, 0); free_initrd(); - return; + return 0; } printk("it isn't (%s); looks like an initrd\n", err); fd = sys_open("/initrd.image", O_WRONLY|O_CREAT, 0700); @@ -565,4 +565,6 @@ void __init populate_rootfs(void) #endif } #endif + return 0; } +rootfs_initcall(populate_rootfs); diff --git a/init/main.c b/init/main.c index fcd9ddc3ccf5..e3f0bb20b4dd 100644 --- a/init/main.c +++ b/init/main.c @@ -94,7 +94,6 @@ extern void pidmap_init(void); extern void prio_tree_init(void); extern void radix_tree_init(void); extern void free_initmem(void); -extern void populate_rootfs(void); extern void driver_init(void); extern void prepare_namespace(void); #ifdef CONFIG_ACPI @@ -745,12 +744,6 @@ static int init(void * unused) cpuset_init_smp(); - /* - * Do this before initcalls, because some drivers want to access - * firmware files. - */ - populate_rootfs(); - do_basic_setup(); /* -- cgit v1.2.3