diff options
| author |   David Rientjes <rientjes@google.com> | 2007-05-08 00:31:43 -0700 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-05-08 11:15:14 -0700 |
| commit | 6f7f02e78a75a09195d963e0392b195bc2d55c5c (patch) | |
| tree | a0ead177a4faaafdfa400ff9de3c992603e42f4d /kernel/cpuset.c | |
| parent | procfs: use simple_read_from_buffer() (diff) | |
| download | linux-dev-6f7f02e78a75a09195d963e0392b195bc2d55c5c.tar.xz linux-dev-6f7f02e78a75a09195d963e0392b195bc2d55c5c.zip | |
cpusets: allow empty {cpus,mems}_allowed to be set for unpopulated cpuset
You currently cannot remove all cpus or mems from cpus_allowed or
mems_allowed of a cpuset. We now allow both if there are no attached
tasks.
Acked-by: Paul Jackson <pj@sgi.com>
Cc: Christoph Lameter <clameter@engr.sgi.com>
Signed-off-by: Paul Menage <menage@google.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/cpuset.c')
| -rw-r--r-- | kernel/cpuset.c | 38 |
1 files changed, 30 insertions, 8 deletions
diff --git a/kernel/cpuset.c b/kernel/cpuset.c index e6d002fc7392..88b416dfbc72 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -821,11 +821,22 @@ static int update_cpumask(struct cpuset *cs, char *buf) return -EACCES; trialcs = *cs; - retval = cpulist_parse(buf, trialcs.cpus_allowed); - if (retval < 0) - return retval; + + /* + * We allow a cpuset's cpus_allowed to be empty; if it has attached + * tasks, we'll catch it later when we validate the change and return + * -ENOSPC. + */ + if (!buf[0] || (buf[0] == '\n' && !buf[1])) { + cpus_clear(trialcs.cpus_allowed); + } else { + retval = cpulist_parse(buf, trialcs.cpus_allowed); + if (retval < 0) + return retval; + } cpus_and(trialcs.cpus_allowed, trialcs.cpus_allowed, cpu_online_map); - if (cpus_empty(trialcs.cpus_allowed)) + /* cpus_allowed cannot be empty for a cpuset with attached tasks. */ + if (atomic_read(&cs->count) && cpus_empty(trialcs.cpus_allowed)) return -ENOSPC; retval = validate_change(cs, &trialcs); if (retval < 0) @@ -918,16 +929,27 @@ static int update_nodemask(struct cpuset *cs, char *buf) return -EACCES; trialcs = *cs; - retval = nodelist_parse(buf, trialcs.mems_allowed); - if (retval < 0) - goto done; + + /* + * We allow a cpuset's mems_allowed to be empty; if it has attached + * tasks, we'll catch it later when we validate the change and return + * -ENOSPC. + */ + if (!buf[0] || (buf[0] == '\n' && !buf[1])) { + nodes_clear(trialcs.mems_allowed); + } else { + retval = nodelist_parse(buf, trialcs.mems_allowed); + if (retval < 0) + goto done; + } nodes_and(trialcs.mems_allowed, trialcs.mems_allowed, node_online_map); oldmem = cs->mems_allowed; if (nodes_equal(oldmem, trialcs.mems_allowed)) { retval = 0; /* Too easy - nothing to do */ goto done; } - if (nodes_empty(trialcs.mems_allowed)) { + /* mems_allowed cannot be empty for a cpuset with attached tasks. */ + if (atomic_read(&cs->count) && nodes_empty(trialcs.mems_allowed)) { retval = -ENOSPC; goto done; } |