Messages in this thread Patch in this message | | | Date | Wed, 28 Jan 2009 16:50:20 -0800 | From | Jeremy Fitzhardinge <> | Subject | [PATCH] xen: make sysfs files behave as their names suggest |
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1: make "target_kb" only accept and produce a memory size in kilobytes. 2: add a second "target" file which produces output in bytes, and will accept memparse input (scaled bytes)
This fixes the rather irritating problem that writing the same value read back into target_kb would end up shrinking the domain by a factor of 1024, with generally bad results.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> --- drivers/xen/balloon.c | 33 ++++++++++++++++++++++++++++++++- 1 file changed, 32 insertions(+), 1 deletion(-)
=================================================================== --- a/drivers/xen/balloon.c +++ b/drivers/xen/balloon.c @@ -586,7 +586,7 @@ if (!capable(CAP_SYS_ADMIN)) return -EPERM; - target_bytes = memparse(buf, &endchar); + target_bytes = simple_strtoull(buf, &endchar, 0) * 1024; balloon_set_new_target(target_bytes >> PAGE_SHIFT); @@ -596,8 +596,39 @@ static SYSDEV_ATTR(target_kb, S_IRUGO | S_IWUSR, show_target_kb, store_target_kb); + +static ssize_t show_target(struct sys_device *dev, struct sysdev_attribute *attr, + char *buf) +{ + return sprintf(buf, "%llu\n", + (u64)balloon_stats.target_pages << PAGE_SHIFT); +} + +static ssize_t store_target(struct sys_device *dev, + struct sysdev_attribute *attr, + const char *buf, + size_t count) +{ + char *endchar; + unsigned long long target_bytes; + + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + target_bytes = memparse(buf, &endchar); + + balloon_set_new_target(target_bytes >> PAGE_SHIFT); + + return count; +} + +static SYSDEV_ATTR(target, S_IRUGO | S_IWUSR, + show_target, store_target); + + static struct sysdev_attribute *balloon_attrs[] = { &attr_target_kb, + &attr_target, }; static struct attribute *balloon_info_attrs[] = {
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