diff options
| author | Mike Travis <travis@sgi.com> | 2008-03-25 15:06:55 -0700 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-04-19 19:44:58 +0200 |
| commit | 30ca60c15a725f655e5d3f14e0238a066bc5aeb7 (patch) | |
| tree | 96d36a2cf12e7a964ce4cd0c49d30b2d40f94b52 | |
| parent | 9f0e738f492522a2f70ad9a2a0287e4e966c633a (diff) | |
cpumask: add cpumask_scnprintf_len function
Add a new function cpumask_scnprintf_len() to return the number of
characters needed to display "len" cpumask bits. The current method
of allocating NR_CPUS bytes is incorrect as what's really needed is
9 characters per 32-bit word of cpumask bits (8 hex digits plus the
seperator [','] or the terminating NULL.) This function provides the
caller the means to allocate the correct string length.
Cc: Paul Jackson <pj@sgi.com>
Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
| -rw-r--r-- | include/linux/bitmap.h | 1 | ||||
| -rw-r--r-- | include/linux/cpumask.h | 7 | ||||
| -rw-r--r-- | lib/bitmap.c | 16 |
3 files changed, 24 insertions, 0 deletions
diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h index acad1105d94..1dbe074f1c6 100644 --- a/include/linux/bitmap.h +++ b/include/linux/bitmap.h @@ -108,6 +108,7 @@ extern int __bitmap_weight(const unsigned long *bitmap, int bits); extern int bitmap_scnprintf(char *buf, unsigned int len, const unsigned long *src, int nbits); +extern int bitmap_scnprintf_len(unsigned int len); extern int __bitmap_parse(const char *buf, unsigned int buflen, int is_user, unsigned long *dst, int nbits); extern int bitmap_parse_user(const char __user *ubuf, unsigned int ulen, diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h index 7047f58306a..67e0e38d32b 100644 --- a/include/linux/cpumask.h +++ b/include/linux/cpumask.h @@ -273,6 +273,13 @@ static inline int __cpumask_scnprintf(char *buf, int len, return bitmap_scnprintf(buf, len, srcp->bits, nbits); } +#define cpumask_scnprintf_len(len) \ + __cpumask_scnprintf_len((len)) +static inline int __cpumask_scnprintf_len(int len) +{ + return bitmap_scnprintf_len(len); +} + #define cpumask_parse_user(ubuf, ulen, dst) \ __cpumask_parse_user((ubuf), (ulen), &(dst), NR_CPUS) static inline int __cpumask_parse_user(const char __user *buf, int len, diff --git a/lib/bitmap.c b/lib/bitmap.c index 2c9242e3fed..a6939e18d7b 100644 --- a/lib/bitmap.c +++ b/lib/bitmap.c @@ -316,6 +316,22 @@ int bitmap_scnprintf(char *buf, unsigned int buflen, EXPORT_SYMBOL(bitmap_scnprintf); /** + * bitmap_scnprintf_len - return buffer length needed to convert + * bitmap to an ASCII hex string. + * @len: number of bits to be converted + */ +int bitmap_scnprintf_len(unsigned int len) +{ + /* we need 9 chars per word for 32 bit words (8 hexdigits + sep/null) */ + int bitslen = ALIGN(len, CHUNKSZ); + int wordlen = CHUNKSZ / 4; + int buflen = (bitslen / wordlen) * (wordlen + 1) * sizeof(char); + + return buflen; +} +EXPORT_SYMBOL(bitmap_scnprintf_len); + +/** * __bitmap_parse - convert an ASCII hex string into a bitmap. * @buf: pointer to buffer containing string. * @buflen: buffer size in bytes. If string is smaller than this |