diff options
| author | Zhang Yanfei <zhangyanfei@cn.fujitsu.com> | 2013-03-28 16:15:35 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-03-29 09:17:22 -0700 |
| commit | eca4549f57a19f8881dcd7b9cef719b3452003c0 (patch) | |
| tree | e7b156e0d7c9344337263ed81d683d15203b08fa /drivers/base/cpu.c | |
| parent | 6ae07f27ab202069bd567967a0099070eb7f77d5 (diff) | |
sysfs: Add crash_notes_size to export percpu note size
For percpu notes, we are exporting only address and not size. So
the userspace tool kexec-tools is putting an upper limit of 1024
and putting the value in p_memsz and p_filesz fields. So the patch
add the new sysfile crash_notes_size to export the exact percpu
note size and let the kexec-tools parse it intead of using 1024.
The idea came from Vivek Goyal. And a later patch will be sent to
kexec-tools to let it parse the size.
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Acked-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/base/cpu.c')
| -rw-r--r-- | drivers/base/cpu.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c index fb10728f6372..a55b5909176f 100644 --- a/drivers/base/cpu.c +++ b/drivers/base/cpu.c @@ -132,6 +132,17 @@ static ssize_t show_crash_notes(struct device *dev, struct device_attribute *att return rc; } static DEVICE_ATTR(crash_notes, 0400, show_crash_notes, NULL); + +static ssize_t show_crash_notes_size(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + ssize_t rc; + + rc = sprintf(buf, "%lu\n", sizeof(note_buf_t)); + return rc; +} +static DEVICE_ATTR(crash_notes_size, 0400, show_crash_notes_size, NULL); #endif /* @@ -259,6 +270,9 @@ int __cpuinit register_cpu(struct cpu *cpu, int num) #ifdef CONFIG_KEXEC if (!error) error = device_create_file(&cpu->dev, &dev_attr_crash_notes); + if (!error) + error = device_create_file(&cpu->dev, + &dev_attr_crash_notes_size); #endif return error; } |