linux/Documentation/ABI/testing/sysfs-profiling

What:		/sys/kernel/profiling
Date:		September 2008
Contact:	Dave Hansen <dave@linux.vnet.ibm.com>
Description:
		/sys/kernel/profiling is the runtime equivalent
		of the boot-time profile= option.

		You can get the same effect running:

			echo 2 > /sys/kernel/profiling

		as you would by issuing profile=2 on the boot
		command line.
doc: Update the name of profiling based on sysfs The ./kernel/ksysfs.c defines 'profiling' w/o 'profile' like "KERNEL_ATTR_RW(profiling)". We need to synchronize the content between ksys.c source and kernel doc. Signed-off-by: Hyeonjun Lim <hjoon0510@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz> 2012-12-03 06:31:31 +00:00			`What: /sys/kernel/profiling`
profiling: dynamically enable readprofile at runtime Way too often, I have a machine that exhibits some kind of crappy behavior. The CPU looks wedged in the kernel or it is spending way too much system time and I wonder what is responsible. I try to run readprofile. But, of course, Ubuntu doesn't enable it by default. Dang! The reason we boot-time enable it is that it takes a big bufffer that we generally can only bootmem alloc. But, does it hurt to at least try and runtime-alloc it? To use: echo 2 > /sys/kernel/profile Then run readprofile like normal. This should fix the compile issue with allmodconfig. I've compile-tested on a bunch more configs now including a few more architectures. Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 2008-10-16 05:01:46 +00:00			`Date: September 2008`
			`Contact: Dave Hansen <dave@linux.vnet.ibm.com>`
			`Description:`
doc: Update the name of profiling based on sysfs The ./kernel/ksysfs.c defines 'profiling' w/o 'profile' like "KERNEL_ATTR_RW(profiling)". We need to synchronize the content between ksys.c source and kernel doc. Signed-off-by: Hyeonjun Lim <hjoon0510@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz> 2012-12-03 06:31:31 +00:00			`/sys/kernel/profiling is the runtime equivalent`
profiling: dynamically enable readprofile at runtime Way too often, I have a machine that exhibits some kind of crappy behavior. The CPU looks wedged in the kernel or it is spending way too much system time and I wonder what is responsible. I try to run readprofile. But, of course, Ubuntu doesn't enable it by default. Dang! The reason we boot-time enable it is that it takes a big bufffer that we generally can only bootmem alloc. But, does it hurt to at least try and runtime-alloc it? To use: echo 2 > /sys/kernel/profile Then run readprofile like normal. This should fix the compile issue with allmodconfig. I've compile-tested on a bunch more configs now including a few more architectures. Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 2008-10-16 05:01:46 +00:00			`of the boot-time profile= option.`

			`You can get the same effect running:`

doc: Update the name of profiling based on sysfs The ./kernel/ksysfs.c defines 'profiling' w/o 'profile' like "KERNEL_ATTR_RW(profiling)". We need to synchronize the content between ksys.c source and kernel doc. Signed-off-by: Hyeonjun Lim <hjoon0510@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz> 2012-12-03 06:31:31 +00:00			`echo 2 > /sys/kernel/profiling`
profiling: dynamically enable readprofile at runtime Way too often, I have a machine that exhibits some kind of crappy behavior. The CPU looks wedged in the kernel or it is spending way too much system time and I wonder what is responsible. I try to run readprofile. But, of course, Ubuntu doesn't enable it by default. Dang! The reason we boot-time enable it is that it takes a big bufffer that we generally can only bootmem alloc. But, does it hurt to at least try and runtime-alloc it? To use: echo 2 > /sys/kernel/profile Then run readprofile like normal. This should fix the compile issue with allmodconfig. I've compile-tested on a bunch more configs now including a few more architectures. Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 2008-10-16 05:01:46 +00:00
			`as you would by issuing profile=2 on the boot`
			`command line.`