From mboxrd@z Thu Jan 1 00:00:00 1970 From: riel@redhat.com Subject: [PATCH 2/2] cpusets,isolcpus: add file to show isolated cpus in cpuset Date: Mon, 23 Feb 2015 16:45:06 -0500 Message-ID: <1424727906-4460-3-git-send-email-riel@redhat.com> References: <1424727906-4460-1-git-send-email-riel@redhat.com> Return-path: In-Reply-To: <1424727906-4460-1-git-send-email-riel@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-kernel@vger.kernel.org Cc: Rik van Riel , Peter Zijlstra , Clark Williams , Li Zefan , Ingo Molnar , Luiz Capitulino , cgroups@vger.kernel.org From: Rik van Riel 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. Cc: Peter Zijlstra Cc: Clark Williams Cc: Li Zefan Cc: Ingo Molnar Cc: Luiz Capitulino Cc: cgroups@vger.kernel.org Signed-off-by: Rik van Riel --- kernel/cpuset.c | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) diff --git a/kernel/cpuset.c b/kernel/cpuset.c index 1ad63fa37cb4..19ad5d3377f8 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 +1705,23 @@ static ssize_t cpuset_write_resmask(struct kernfs_open_file *of, return retval ?: nbytes; } +static size_t cpuset_sprintf_isolcpus(char *s, ssize_t pos, struct cpuset *cs) +{ + cpumask_var_t my_isolated_cpus; + ssize_t count; + + if (!alloc_cpumask_var(&my_isolated_cpus, GFP_KERNEL)) + return 0; + + cpumask_and(my_isolated_cpus, cs->cpus_allowed, cpu_isolated_map); + + count = cpulist_scnprintf(s, pos, my_isolated_cpus); + + free_cpumask_var(my_isolated_cpus); + + return count; +} + /* * 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 @@ -1738,6 +1756,9 @@ static int cpuset_common_seq_show(struct seq_file *sf, void *v) case FILE_EFFECTIVE_MEMLIST: s += nodelist_scnprintf(s, count, cs->effective_mems); break; + case FILE_ISOLCPUS: + s += cpuset_sprintf_isolcpus(s, count, cs); + break; default: ret = -EINVAL; goto out_unlock; @@ -1906,6 +1927,12 @@ static struct cftype files[] = { .private = FILE_MEMORY_PRESSURE_ENABLED, }, + { + .name = "isolcpus", + .seq_show = cpuset_common_seq_show, + .private = FILE_ISOLCPUS, + }, + { } /* terminate */ }; -- 1.9.3