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drivers/base/node.c: use bin_attribute to break the size limitation of cpumap ABI

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Reading /sys/devices/system/cpu/cpuX/nodeX/ returns cpumap and cpulist.
However, the size of this file is limited to PAGE_SIZE because of the
limitation for sysfs attribute.

This patch moves to use bin_attribute to extend the ABI to be more
than one page so that cpumap bitmask and list won't be potentially
trimmed.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Tian Tao <tiantao6@hisilicon.com>
Signed-off-by: Barry Song <song.bao.hua@hisilicon.com>
Link: https://lore.kernel.org/r/20210806110251.560-5-song.bao.hua@hisilicon.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Tian Tao 2021-08-06 23:02:50 +12:00 committed by Greg Kroah-Hartman
parent bb9ec13d15
commit 75bd50fa84
1 changed files with 42 additions and 25 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

67
drivers/base/node.c
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@ -26,43 +26,47 @@ static struct bus_type node_subsys = {
.dev_name = "node",
};
static ssize_t node_read_cpumap(struct device *dev, bool list, char *buf)
static inline ssize_t cpumap_read(struct file *file, struct kobject *kobj,
struct bin_attribute *attr, char *buf,
loff_t off, size_t count)
{
ssize_t n;
cpumask_var_t mask;
struct device *dev = kobj_to_dev(kobj);
struct node *node_dev = to_node(dev);
/* 2008/04/07: buf currently PAGE_SIZE, need 9 chars per 32 bits. */
BUILD_BUG_ON((NR_CPUS/32 * 9) > (PAGE_SIZE-1));
cpumask_var_t mask;
ssize_t n;
if (!alloc_cpumask_var(&mask, GFP_KERNEL))
return 0;
cpumask_and(mask, cpumask_of_node(node_dev->dev.id), cpu_online_mask);
n = cpumap_print_to_pagebuf(list, buf, mask);
n = cpumap_print_bitmask_to_buf(buf, mask, off, count);
free_cpumask_var(mask);
return n;
}
static inline ssize_t cpumap_show(struct device *dev,
struct device_attribute *attr,
char *buf)
static BIN_ATTR_RO(cpumap, 0);
static inline ssize_t cpulist_read(struct file *file, struct kobject *kobj,
struct bin_attribute *attr, char *buf,
loff_t off, size_t count)
{
return node_read_cpumap(dev, false, buf);
struct device *dev = kobj_to_dev(kobj);
struct node *node_dev = to_node(dev);
cpumask_var_t mask;
ssize_t n;
if (!alloc_cpumask_var(&mask, GFP_KERNEL))
return 0;
cpumask_and(mask, cpumask_of_node(node_dev->dev.id), cpu_online_mask);
n = cpumap_print_list_to_buf(buf, mask, off, count);
free_cpumask_var(mask);
return n;
}
static DEVICE_ATTR_RO(cpumap);
static inline ssize_t cpulist_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
return node_read_cpumap(dev, true, buf);
}
static DEVICE_ATTR_RO(cpulist);
static BIN_ATTR_RO(cpulist, 0);
/**
* struct node_access_nodes - Access class device to hold user visible
@ -557,15 +561,28 @@ static ssize_t node_read_distance(struct device *dev,
static DEVICE_ATTR(distance, 0444, node_read_distance, NULL);
static struct attribute *node_dev_attrs[] = {
&dev_attr_cpumap.attr,
&dev_attr_cpulist.attr,
&dev_attr_meminfo.attr,
&dev_attr_numastat.attr,
&dev_attr_distance.attr,
&dev_attr_vmstat.attr,
NULL
};
ATTRIBUTE_GROUPS(node_dev);
static struct bin_attribute *node_dev_bin_attrs[] = {
&bin_attr_cpumap,
&bin_attr_cpulist,
NULL
};
static const struct attribute_group node_dev_group = {
.attrs = node_dev_attrs,
.bin_attrs = node_dev_bin_attrs
};
static const struct attribute_group *node_dev_groups[] = {
&node_dev_group,
NULL
};
#ifdef CONFIG_HUGETLBFS
/*