From e162b39a368f0401e41b558f430c354d12a85b37 Mon Sep 17 00:00:00 2001 From: Mandeep Singh Baines Date: Thu, 15 Jan 2009 11:08:40 -0800 Subject: softlockup: decouple hung tasks check from softlockup detection Decoupling allows: * hung tasks check to happen at very low priority * hung tasks check and softlockup to be enabled/disabled independently at compile and/or run-time * individual panic settings to be enabled disabled independently at compile and/or run-time * softlockup threshold to be reduced without increasing hung tasks poll frequency (hung task check is expensive relative to softlock watchdog) * hung task check to be zero over-head when disabled at run-time Signed-off-by: Mandeep Singh Baines Signed-off-by: Ingo Molnar --- lib/Kconfig.debug | 38 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 38 insertions(+) (limited to 'lib') diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 4c9ae6085c75..883ecea22f37 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -186,6 +186,44 @@ config BOOTPARAM_SOFTLOCKUP_PANIC_VALUE default 0 if !BOOTPARAM_SOFTLOCKUP_PANIC default 1 if BOOTPARAM_SOFTLOCKUP_PANIC +config DETECT_HUNG_TASK + bool "Detect Hung Tasks" + depends on DEBUG_KERNEL + default y + help + Say Y here to enable the kernel to detect "hung tasks", + which are bugs that cause the task to be stuck in + uninterruptible "D" state indefinitiley. + + When a hung task is detected, the kernel will print the + current stack trace (which you should report), but the + task will stay in uninterruptible state. If lockdep is + enabled then all held locks will also be reported. This + feature has negligible overhead. + +config BOOTPARAM_HUNG_TASK_PANIC + bool "Panic (Reboot) On Hung Tasks" + depends on DETECT_HUNG_TASK + help + Say Y here to enable the kernel to panic on "hung tasks", + which are bugs that cause the kernel to leave a task stuck + in uninterruptible "D" state. + + The panic can be used in combination with panic_timeout, + to cause the system to reboot automatically after a + hung task has been detected. This feature is useful for + high-availability systems that have uptime guarantees and + where a hung tasks must be resolved ASAP. + + Say N if unsure. + +config BOOTPARAM_HUNG_TASK_PANIC_VALUE + int + depends on DETECT_HUNG_TASK + range 0 1 + default 0 if !BOOTPARAM_HUNG_TASK_PANIC + default 1 if BOOTPARAM_HUNG_TASK_PANIC + config SCHED_DEBUG bool "Collect scheduler debugging info" depends on DEBUG_KERNEL && PROC_FS -- cgit v1.2.2 From 77d05632baee21b1cef8730d7c06aa69601e4dca Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Tue, 7 Apr 2009 08:55:36 +0200 Subject: softlockup: make DETECT_HUNG_TASK default depend on DETECT_SOFTLOCKUP Don't offer a default-y option when the user has turned off CONFIG_DETECT_SOFTLOCKUP already. Do offer it as 'y' only if DETECT_SOFTLOCKUP is on already. This makes it match previous behavior - where the hung-task check was embedded i CONFIG_DETECT_SOFTLOCKUP code. Cc: Linus Torvalds Signed-off-by: Ingo Molnar --- lib/Kconfig.debug | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'lib') diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 4934eaa21e1e..898e07c33c3c 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -189,7 +189,7 @@ config BOOTPARAM_SOFTLOCKUP_PANIC_VALUE config DETECT_HUNG_TASK bool "Detect Hung Tasks" depends on DEBUG_KERNEL - default y + default DETECT_SOFTLOCKUP help Say Y here to enable the kernel to detect "hung tasks", which are bugs that cause the task to be stuck in -- cgit v1.2.2 From 284901a90a9e0b812ca3f5f852cbbfb60d10249d Mon Sep 17 00:00:00 2001 From: Yang Hongyang Date: Mon, 6 Apr 2009 19:01:15 -0700 Subject: dma-mapping: replace all DMA_32BIT_MASK macro with DMA_BIT_MASK(32) Replace all DMA_32BIT_MASK macro with DMA_BIT_MASK(32) Signed-off-by: Yang Hongyang Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/swiotlb.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'lib') diff --git a/lib/swiotlb.c b/lib/swiotlb.c index 32e2bd3b1142..2b0b5a7d2ced 100644 --- a/lib/swiotlb.c +++ b/lib/swiotlb.c @@ -549,7 +549,7 @@ swiotlb_alloc_coherent(struct device *hwdev, size_t size, dma_addr_t dev_addr; void *ret; int order = get_order(size); - u64 dma_mask = DMA_32BIT_MASK; + u64 dma_mask = DMA_BIT_MASK(32); if (hwdev && hwdev->coherent_dma_mask) dma_mask = hwdev->coherent_dma_mask; -- cgit v1.2.2 From 022624a758dc9489388a99ad29577b4c8c09237c Mon Sep 17 00:00:00 2001 From: Zhaolei Date: Fri, 27 Mar 2009 17:09:10 +0800 Subject: printk: fix wrong format string iter for printk printk("%Q"); Output before patch: %QQ Output after patch: %Q Signed-off-by: Zhao Lei Acked-by: Lai Jiangshan Acked-by: Frederic Weisbecker Cc: torvalds@linux-foundation.org Cc: Steven Rostedt LKML-Reference: <49CC97B6.7040809@cn.fujitsu.com> Signed-off-by: Ingo Molnar --- lib/vsprintf.c | 16 ---------------- 1 file changed, 16 deletions(-) (limited to 'lib') diff --git a/lib/vsprintf.c b/lib/vsprintf.c index be3001f912e4..7536acea135b 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -1051,13 +1051,6 @@ int vsnprintf(char *buf, size_t size, const char *fmt, va_list args) if (str < end) *str = '%'; ++str; - if (*fmt) { - if (str < end) - *str = *fmt; - ++str; - } else { - --fmt; - } break; case FORMAT_TYPE_NRCHARS: { @@ -1339,8 +1332,6 @@ do { \ break; case FORMAT_TYPE_INVALID: - if (!*fmt) - --fmt; break; case FORMAT_TYPE_NRCHARS: { @@ -1523,13 +1514,6 @@ int bstr_printf(char *buf, size_t size, const char *fmt, const u32 *bin_buf) if (str < end) *str = '%'; ++str; - if (*fmt) { - if (str < end) - *str = *fmt; - ++str; - } else { - --fmt; - } break; case FORMAT_TYPE_NRCHARS: -- cgit v1.2.2 From 9eeba6138cefc0435695463ddadb0d95e0a6bcd2 Mon Sep 17 00:00:00 2001 From: Frederic Weisbecker Date: Sat, 11 Apr 2009 03:17:17 +0200 Subject: lockdep: warn about lockdep disabling after kernel taint Impact: provide useful missing info for developers Kernel taint can occur in several situations such as warnings, load of prorietary or staging modules, bad page, etc... But when such taint happens, a developer might still be working on the kernel, expecting that lockdep is still enabled. But a taint disables lockdep without ever warning about it. Such a kernel behaviour doesn't really help for kernel development. This patch adds this missing warning. Since the taint is done most of the time after the main message that explain the real source issue, it seems safe to warn about it inside add_taint() so that it appears at last, without hurting the main information. v2: Use a generic helper to disable lockdep instead of an open coded xchg(). Signed-off-by: Frederic Weisbecker Cc: Peter Zijlstra LKML-Reference: <1239412638-6739-1-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar --- lib/debug_locks.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'lib') diff --git a/lib/debug_locks.c b/lib/debug_locks.c index 0218b4693dd8..bc3b11731b9c 100644 --- a/lib/debug_locks.c +++ b/lib/debug_locks.c @@ -36,7 +36,7 @@ int debug_locks_silent; */ int debug_locks_off(void) { - if (xchg(&debug_locks, 0)) { + if (__debug_locks_off()) { if (!debug_locks_silent) { oops_in_progress = 1; console_verbose(); -- cgit v1.2.2 From 05f54c13cd0c33694eec39a265475c5d6cf223cf Mon Sep 17 00:00:00 2001 From: Hugh Dickins Date: Thu, 16 Apr 2009 21:55:29 +0100 Subject: Revert "kobject: don't block for each kobject_uevent". This reverts commit f520360d93cdc37de5d972dac4bf3bdef6a7f6a7. Tetsuo Handa, running a kernel with CONFIG_DEBUG_PAGEALLOC=y and CONFIG_UEVENT_HELPER_PATH=/sbin/hotplug, has been hitting RCU detected CPU stalls: it's been spinning in the loop where do_execve() counts up the args (but why wasn't fixup_exception working? dunno). The recent change, switching kobject_uevent_env() from UMH_WAIT_EXEC to UMH_NO_WAIT, is broken: the exec uses args on the local stack here, and an env which is kfreed as soon as call_usermodehelper() returns. It very much needs to wait for the exec to be done. An alternative would be to keep the UMH_NO_WAIT, and complicate the code to allocate and free these resources correctly? but no, as GregKH pointed out when making the commit, CONFIG_UEVENT_HELPER_PATH="" is a much better optimization - though some distros are still saying /sbin/hotplug in their .config, yet with no such binary in their initrd or their root. Reported-by: Tetsuo Handa Signed-off-by: Hugh Dickins Acked-by: Greg Kroah-Hartman Acked-by: Arjan van de Ven Acked-by: Will Newton Signed-off-by: Linus Torvalds --- lib/kobject_uevent.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'lib') diff --git a/lib/kobject_uevent.c b/lib/kobject_uevent.c index 97a777ad4f59..dafeecf5b143 100644 --- a/lib/kobject_uevent.c +++ b/lib/kobject_uevent.c @@ -258,7 +258,7 @@ int kobject_uevent_env(struct kobject *kobj, enum kobject_action action, goto exit; retval = call_usermodehelper(argv[0], argv, - env->envp, UMH_NO_WAIT); + env->envp, UMH_WAIT_EXEC); } exit: -- cgit v1.2.2 From d094cbe998eb566d47552aa9d3c26c9123a7b858 Mon Sep 17 00:00:00 2001 From: Kay Sievers Date: Fri, 3 Apr 2009 19:04:15 +0200 Subject: driver core: allow non-root users to listen to uevents Users can read sysfs files, there is no reason they should not be allowed to listen to uevents. This lets xorg and other userspace programs properly get these messages without having to be root. Signed-off-by: Kay Sievers Signed-off-by: Greg Kroah-Hartman --- lib/kobject_uevent.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'lib') diff --git a/lib/kobject_uevent.c b/lib/kobject_uevent.c index dafeecf5b143..920a3ca6e259 100644 --- a/lib/kobject_uevent.c +++ b/lib/kobject_uevent.c @@ -328,7 +328,7 @@ static int __init kobject_uevent_init(void) "kobject_uevent: unable to create netlink socket!\n"); return -ENODEV; } - + netlink_set_nonroot(NETLINK_KOBJECT_UEVENT, NL_NONROOT_RECV); return 0; } -- cgit v1.2.2 From 8a577ffc75d9194fe8cdb7479236f2081c26ca1f Mon Sep 17 00:00:00 2001 From: Kay Sievers Date: Sat, 18 Apr 2009 15:05:45 -0700 Subject: driver: dont update dev_name via device_add path notice one system /proc/iomem some entries missed the name for pci_devices it turns that dev->dev.kobj name is changed after device_add. for pci code: via acpi_pci_root_driver.ops.add (aka acpi_pci_root_add) ==> pci_acpi_scan_root is used to scan pci bus/device, and at the same time we read the resource for pci_dev in the pci_read_bases, we have res->name = pci_name(pci_dev); pci_name is calling dev_name. later via acpi_pci_root_driver.ops.start (aka acpi_pci_root_start) ==> pci_bus_add_device to add all pci_dev in kobj tree. pci_bus_add_device will call device_add. actually in device_add /* first, register with generic layer. */ error = kobject_add(&dev->kobj, dev->kobj.parent, "%s", dev_name(dev)); if (error) goto Error; will get one new name for that kobj, old name is freed. [Impact: fix corrupted names in /proc/iomem ] Signed-off-by: Yinghai Lu Signed-off-by: Linus Torvalds --- lib/kobject.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'lib') diff --git a/lib/kobject.c b/lib/kobject.c index a6dec32f2ddd..bacf6fe4f7a0 100644 --- a/lib/kobject.c +++ b/lib/kobject.c @@ -218,6 +218,9 @@ int kobject_set_name_vargs(struct kobject *kobj, const char *fmt, const char *old_name = kobj->name; char *s; + if (kobj->name && !fmt) + return 0; + kobj->name = kvasprintf(GFP_KERNEL, fmt, vargs); if (!kobj->name) return -ENOMEM; -- cgit v1.2.2