From dc52ddc0e6f45b04780b26fc0813509f8e798c42 Mon Sep 17 00:00:00 2001 From: Matt Helsley Date: Sat, 18 Oct 2008 20:27:21 -0700 Subject: container freezer: implement freezer cgroup subsystem This patch implements a new freezer subsystem in the control groups framework. It provides a way to stop and resume execution of all tasks in a cgroup by writing in the cgroup filesystem. The freezer subsystem in the container filesystem defines a file named freezer.state. Writing "FROZEN" to the state file will freeze all tasks in the cgroup. Subsequently writing "RUNNING" will unfreeze the tasks in the cgroup. Reading will return the current state. * Examples of usage : # mkdir /containers/freezer # mount -t cgroup -ofreezer freezer /containers # mkdir /containers/0 # echo $some_pid > /containers/0/tasks to get status of the freezer subsystem : # cat /containers/0/freezer.state RUNNING to freeze all tasks in the container : # echo FROZEN > /containers/0/freezer.state # cat /containers/0/freezer.state FREEZING # cat /containers/0/freezer.state FROZEN to unfreeze all tasks in the container : # echo RUNNING > /containers/0/freezer.state # cat /containers/0/freezer.state RUNNING This is the basic mechanism which should do the right thing for user space task in a simple scenario. It's important to note that freezing can be incomplete. In that case we return EBUSY. This means that some tasks in the cgroup are busy doing something that prevents us from completely freezing the cgroup at this time. After EBUSY, the cgroup will remain partially frozen -- reflected by freezer.state reporting "FREEZING" when read. The state will remain "FREEZING" until one of these things happens: 1) Userspace cancels the freezing operation by writing "RUNNING" to the freezer.state file 2) Userspace retries the freezing operation by writing "FROZEN" to the freezer.state file (writing "FREEZING" is not legal and returns EIO) 3) The tasks that blocked the cgroup from entering the "FROZEN" state disappear from the cgroup's set of tasks. [akpm@linux-foundation.org: coding-style fixes] [akpm@linux-foundation.org: export thaw_process] Signed-off-by: Cedric Le Goater Signed-off-by: Matt Helsley Acked-by: Serge E. Hallyn Tested-by: Matt Helsley Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/m32r/Kconfig | 2 ++ 1 file changed, 2 insertions(+) (limited to 'arch/m32r/Kconfig') diff --git a/arch/m32r/Kconfig b/arch/m32r/Kconfig index 00289c178f89..dbaed4a63815 100644 --- a/arch/m32r/Kconfig +++ b/arch/m32r/Kconfig @@ -42,6 +42,8 @@ config HZ source "init/Kconfig" +source "kernel/Kconfig.freezer" + menu "Processor type and features" -- cgit v1.2.3 From ae1e9130bfb9ad55eb97ec3fb17a122b7a118f98 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Tue, 11 Nov 2008 09:05:16 +0100 Subject: sched: rename SCHED_NO_NO_OMIT_FRAME_POINTER => SCHED_OMIT_FRAME_POINTER Impact: cleanup, change .config option name We had this ugly config name for a long time for hysteric raisons. Rename it to a saner name. We still cannot get rid of it completely, until /proc//stack usage replaces WCHAN usage for good. We'll be able to do that in the v2.6.29/v2.6.30 timeframe. Signed-off-by: Ingo Molnar --- arch/ia64/Kconfig | 2 +- arch/m32r/Kconfig | 2 +- arch/mips/Kconfig | 2 +- arch/powerpc/Kconfig | 2 +- arch/x86/Kconfig | 2 +- include/asm-m32r/system.h | 2 +- kernel/Makefile | 2 +- 7 files changed, 7 insertions(+), 7 deletions(-) (limited to 'arch/m32r/Kconfig') diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig index 27eec71429b0..59d12788b60c 100644 --- a/arch/ia64/Kconfig +++ b/arch/ia64/Kconfig @@ -99,7 +99,7 @@ config GENERIC_IOMAP bool default y -config SCHED_NO_NO_OMIT_FRAME_POINTER +config SCHED_OMIT_FRAME_POINTER bool default y diff --git a/arch/m32r/Kconfig b/arch/m32r/Kconfig index dbaed4a63815..29047d5c259a 100644 --- a/arch/m32r/Kconfig +++ b/arch/m32r/Kconfig @@ -273,7 +273,7 @@ config GENERIC_CALIBRATE_DELAY bool default y -config SCHED_NO_NO_OMIT_FRAME_POINTER +config SCHED_OMIT_FRAME_POINTER bool default y diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig index f4af967a6b30..a5255e7c79e0 100644 --- a/arch/mips/Kconfig +++ b/arch/mips/Kconfig @@ -653,7 +653,7 @@ config GENERIC_CMOS_UPDATE bool default y -config SCHED_NO_NO_OMIT_FRAME_POINTER +config SCHED_OMIT_FRAME_POINTER bool default y diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 525c13a4de93..adb23ea1c1ef 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -141,7 +141,7 @@ config GENERIC_NVRAM bool default y if PPC32 -config SCHED_NO_NO_OMIT_FRAME_POINTER +config SCHED_OMIT_FRAME_POINTER bool default y diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 1d5550d19b66..74db682ec1ce 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -364,7 +364,7 @@ config X86_RDC321X as R-8610-(G). If you don't have one of these chips, you should say N here. -config SCHED_NO_NO_OMIT_FRAME_POINTER +config SCHED_OMIT_FRAME_POINTER def_bool y prompt "Single-depth WCHAN output" depends on X86 diff --git a/include/asm-m32r/system.h b/include/asm-m32r/system.h index 70a57c8c002b..c980f5ba8de7 100644 --- a/include/asm-m32r/system.h +++ b/include/asm-m32r/system.h @@ -23,7 +23,7 @@ */ #if defined(CONFIG_FRAME_POINTER) || \ - !defined(CONFIG_SCHED_NO_NO_OMIT_FRAME_POINTER) + !defined(CONFIG_SCHED_OMIT_FRAME_POINTER) #define M32R_PUSH_FP " push fp\n" #define M32R_POP_FP " pop fp\n" #else diff --git a/kernel/Makefile b/kernel/Makefile index e1af03972148..46e67a398495 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -91,7 +91,7 @@ obj-$(CONFIG_FUNCTION_TRACER) += trace/ obj-$(CONFIG_TRACING) += trace/ obj-$(CONFIG_SMP) += sched_cpupri.o -ifneq ($(CONFIG_SCHED_NO_NO_OMIT_FRAME_POINTER),y) +ifneq ($(CONFIG_SCHED_OMIT_FRAME_POINTER),y) # According to Alan Modra , the -fno-omit-frame-pointer is # needed for x86 only. Why this used to be enabled for all architectures is beyond # me. I suspect most platforms don't need this, but until we know that for sure -- cgit v1.2.3