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authorPaul Menage <menage@google.com>2008-04-29 04:00:06 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2008-04-29 11:06:09 -0400
commite73d2c61d1fcbd3621688ae457b49509c8d4c601 (patch)
treee54b1543e786afd036b7884776a6753d8a8973f6 /kernel
parent418d7d875ce7f33ef0d48d7cc3a95f31302dcf56 (diff)
CGroups _s64 files: add cgroups read_s64/write_s64 file methods
These patches add cgroups read_s64 and write_s64 control file methods (the signed equivalent of read_u64/write_u64) and use them to implement the cpu.rt_runtime_us control file in the CFS cgroup subsystem. This patch: These are the signed equivalents of the read_u64/write_u64 methods Signed-off-by: Paul Menage <menage@google.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/cgroup.c38
1 files changed, 28 insertions, 10 deletions
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index b5ef0c4772f7..bd6122ccc0ba 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -1299,14 +1299,13 @@ enum cgroup_filetype {
1299 FILE_RELEASE_AGENT, 1299 FILE_RELEASE_AGENT,
1300}; 1300};
1301 1301
1302static ssize_t cgroup_write_u64(struct cgroup *cgrp, struct cftype *cft, 1302static ssize_t cgroup_write_X64(struct cgroup *cgrp, struct cftype *cft,
1303 struct file *file, 1303 struct file *file,
1304 const char __user *userbuf, 1304 const char __user *userbuf,
1305 size_t nbytes, loff_t *unused_ppos) 1305 size_t nbytes, loff_t *unused_ppos)
1306{ 1306{
1307 char buffer[64]; 1307 char buffer[64];
1308 int retval = 0; 1308 int retval = 0;
1309 u64 val;
1310 char *end; 1309 char *end;
1311 1310
1312 if (!nbytes) 1311 if (!nbytes)
@@ -1318,12 +1317,17 @@ static ssize_t cgroup_write_u64(struct cgroup *cgrp, struct cftype *cft,
1318 1317
1319 buffer[nbytes] = 0; /* nul-terminate */ 1318 buffer[nbytes] = 0; /* nul-terminate */
1320 strstrip(buffer); 1319 strstrip(buffer);
1321 val = simple_strtoull(buffer, &end, 0); 1320 if (cft->write_u64) {
1322 if (*end) 1321 u64 val = simple_strtoull(buffer, &end, 0);
1323 return -EINVAL; 1322 if (*end)
1324 1323 return -EINVAL;
1325 /* Pass to subsystem */ 1324 retval = cft->write_u64(cgrp, cft, val);
1326 retval = cft->write_u64(cgrp, cft, val); 1325 } else {
1326 s64 val = simple_strtoll(buffer, &end, 0);
1327 if (*end)
1328 return -EINVAL;
1329 retval = cft->write_s64(cgrp, cft, val);
1330 }
1327 if (!retval) 1331 if (!retval)
1328 retval = nbytes; 1332 retval = nbytes;
1329 return retval; 1333 return retval;
@@ -1404,8 +1408,8 @@ static ssize_t cgroup_file_write(struct file *file, const char __user *buf,
1404 return -ENODEV; 1408 return -ENODEV;
1405 if (cft->write) 1409 if (cft->write)
1406 return cft->write(cgrp, cft, file, buf, nbytes, ppos); 1410 return cft->write(cgrp, cft, file, buf, nbytes, ppos);
1407 if (cft->write_u64) 1411 if (cft->write_u64 || cft->write_s64)
1408 return cgroup_write_u64(cgrp, cft, file, buf, nbytes, ppos); 1412 return cgroup_write_X64(cgrp, cft, file, buf, nbytes, ppos);
1409 return -EINVAL; 1413 return -EINVAL;
1410} 1414}
1411 1415
@@ -1421,6 +1425,18 @@ static ssize_t cgroup_read_u64(struct cgroup *cgrp, struct cftype *cft,
1421 return simple_read_from_buffer(buf, nbytes, ppos, tmp, len); 1425 return simple_read_from_buffer(buf, nbytes, ppos, tmp, len);
1422} 1426}
1423 1427
1428static ssize_t cgroup_read_s64(struct cgroup *cgrp, struct cftype *cft,
1429 struct file *file,
1430 char __user *buf, size_t nbytes,
1431 loff_t *ppos)
1432{
1433 char tmp[64];
1434 s64 val = cft->read_s64(cgrp, cft);
1435 int len = sprintf(tmp, "%lld\n", (long long) val);
1436
1437 return simple_read_from_buffer(buf, nbytes, ppos, tmp, len);
1438}
1439
1424static ssize_t cgroup_common_file_read(struct cgroup *cgrp, 1440static ssize_t cgroup_common_file_read(struct cgroup *cgrp,
1425 struct cftype *cft, 1441 struct cftype *cft,
1426 struct file *file, 1442 struct file *file,
@@ -1477,6 +1493,8 @@ static ssize_t cgroup_file_read(struct file *file, char __user *buf,
1477 return cft->read(cgrp, cft, file, buf, nbytes, ppos); 1493 return cft->read(cgrp, cft, file, buf, nbytes, ppos);
1478 if (cft->read_u64) 1494 if (cft->read_u64)
1479 return cgroup_read_u64(cgrp, cft, file, buf, nbytes, ppos); 1495 return cgroup_read_u64(cgrp, cft, file, buf, nbytes, ppos);
1496 if (cft->read_s64)
1497 return cgroup_read_s64(cgrp, cft, file, buf, nbytes, ppos);
1480 return -EINVAL; 1498 return -EINVAL;
1481} 1499}
1482 1500