On Thu, 26 Feb 2015 19:05:57 +0800 Zefan Li <[email protected]> wrote:
> Make it return -ENOMEM ? Or make it a global variable and allocate memory for > it > in cpuset_init(). Here you are. This addresses your concern, as well as the issue David Rientjes found earlier. ---8<--- Subject: cpusets,isolcpus: add file to show isolated cpus in cpuset The previous patch makes it so the code skips over isolcpus when building scheduler load balancing domains. This makes it hard to see for a user which of the CPUs in a cpuset are participating in load balancing, and which ones are isolated cpus. Add a cpuset.isolcpus file with info on which cpus in a cpuset are isolated CPUs. This file is read-only for now. In the future we could extend things so isolcpus can be changed at run time, for the root (system wide) cpuset only. Acked-by: David Rientjes <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Clark Williams <[email protected]> Cc: Li Zefan <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Luiz Capitulino <[email protected]> Cc: David Rientjes <[email protected]> Cc: Mike Galbraith <[email protected]> Cc: [email protected] Signed-off-by: Rik van Riel <[email protected]> --- kernel/cpuset.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) diff --git a/kernel/cpuset.c b/kernel/cpuset.c index b544e5229d99..5462e1ca90bd 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -1563,6 +1563,7 @@ typedef enum { FILE_MEMORY_PRESSURE, FILE_SPREAD_PAGE, FILE_SPREAD_SLAB, + FILE_ISOLCPUS, } cpuset_filetype_t; static int cpuset_write_u64(struct cgroup_subsys_state *css, struct cftype *cft, @@ -1704,6 +1705,16 @@ static ssize_t cpuset_write_resmask(struct kernfs_open_file *of, return retval ?: nbytes; } +/* protected by the lock in cpuset_common_seq_show */ +static cpumask_var_t print_isolated_cpus; + +static void cpuset_seq_print_isolcpus(struct seq_file *sf, struct cpuset *cs) +{ + cpumask_and(print_isolated_cpus, cs->cpus_allowed, cpu_isolated_map); + + seq_printf(sf, "%*pbl\n", cpumask_pr_args(print_isolated_cpus)); +} + /* * These ascii lists should be read in a single call, by using a user * buffer large enough to hold the entire map. If read in smaller @@ -1733,6 +1744,9 @@ static int cpuset_common_seq_show(struct seq_file *sf, void *v) case FILE_EFFECTIVE_MEMLIST: seq_printf(sf, "%*pbl\n", nodemask_pr_args(&cs->effective_mems)); break; + case FILE_ISOLCPUS: + cpuset_seq_print_isolcpus(sf, cs); + break; default: ret = -EINVAL; } @@ -1893,6 +1907,12 @@ static struct cftype files[] = { .private = FILE_MEMORY_PRESSURE_ENABLED, }, + { + .name = "isolcpus", + .seq_show = cpuset_common_seq_show, + .private = FILE_ISOLCPUS, + }, + { } /* terminate */ }; @@ -2070,6 +2090,8 @@ int __init cpuset_init(void) BUG(); if (!alloc_cpumask_var(&top_cpuset.effective_cpus, GFP_KERNEL)) BUG(); + if (!alloc_cpumask_var(&print_isolated_cpus, GFP_KERNEL)) + BUG(); cpumask_setall(top_cpuset.cpus_allowed); nodes_setall(top_cpuset.mems_allowed); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
