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authorLinus Torvalds <torvalds@linux-foundation.org>2019-07-09 07:35:12 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2019-07-09 07:35:12 +0300
commit92c1d6522135050cb377a18cc6e30d08dfb87efb (patch)
tree5d2fa3051c975f1c459b6949f9e71cac2edf74de /kernel
parentdf2a40f549e6b73aad98b0c03f400c00d284816b (diff)
parent99c8b231ae6c6ca4ca2fd1c0b3701071f589661f (diff)
downloadlinux-92c1d6522135050cb377a18cc6e30d08dfb87efb.tar.xz
Merge branch 'for-5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup updates from Tejun Heo: "Documentation updates and the addition of cgroup_parse_float() which will be used by new controllers including blk-iocost" * 'for-5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: docs: cgroup-v1: convert docs to ReST and rename to *.rst cgroup: Move cgroup_parse_float() implementation out of CONFIG_SYSFS cgroup: add cgroup_parse_float()
Diffstat (limited to 'kernel')
-rw-r--r--kernel/cgroup/cgroup.c43
-rw-r--r--kernel/cgroup/cpuset.c2
2 files changed, 44 insertions, 1 deletions
diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index cdbeff87fa99..aaba2a41562a 100644
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -6240,6 +6240,48 @@ struct cgroup *cgroup_get_from_fd(int fd)
}
EXPORT_SYMBOL_GPL(cgroup_get_from_fd);
+static u64 power_of_ten(int power)
+{
+ u64 v = 1;
+ while (power--)
+ v *= 10;
+ return v;
+}
+
+/**
+ * cgroup_parse_float - parse a floating number
+ * @input: input string
+ * @dec_shift: number of decimal digits to shift
+ * @v: output
+ *
+ * Parse a decimal floating point number in @input and store the result in
+ * @v with decimal point right shifted @dec_shift times. For example, if
+ * @input is "12.3456" and @dec_shift is 3, *@v will be set to 12345.
+ * Returns 0 on success, -errno otherwise.
+ *
+ * There's nothing cgroup specific about this function except that it's
+ * currently the only user.
+ */
+int cgroup_parse_float(const char *input, unsigned dec_shift, s64 *v)
+{
+ s64 whole, frac = 0;
+ int fstart = 0, fend = 0, flen;
+
+ if (!sscanf(input, "%lld.%n%lld%n", &whole, &fstart, &frac, &fend))
+ return -EINVAL;
+ if (frac < 0)
+ return -EINVAL;
+
+ flen = fend > fstart ? fend - fstart : 0;
+ if (flen < dec_shift)
+ frac *= power_of_ten(dec_shift - flen);
+ else
+ frac = DIV_ROUND_CLOSEST_ULL(frac, power_of_ten(flen - dec_shift));
+
+ *v = whole * power_of_ten(dec_shift) + frac;
+ return 0;
+}
+
/*
* sock->sk_cgrp_data handling. For more info, see sock_cgroup_data
* definition in cgroup-defs.h.
@@ -6402,4 +6444,5 @@ static int __init cgroup_sysfs_init(void)
return sysfs_create_group(kernel_kobj, &cgroup_sysfs_attr_group);
}
subsys_initcall(cgroup_sysfs_init);
+
#endif /* CONFIG_SYSFS */
diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
index a1590e244f5f..b3b02b9c4405 100644
--- a/kernel/cgroup/cpuset.c
+++ b/kernel/cgroup/cpuset.c
@@ -729,7 +729,7 @@ static inline int nr_cpusets(void)
* load balancing domains (sched domains) as specified by that partial
* partition.
*
- * See "What is sched_load_balance" in Documentation/cgroup-v1/cpusets.txt
+ * See "What is sched_load_balance" in Documentation/cgroup-v1/cpusets.rst
* for a background explanation of this.
*
* Does not return errors, on the theory that the callers of this