From mboxrd@z Thu Jan 1 00:00:00 1970 From: riel@redhat.com Subject: [PATCH 3/4] cpusets,isolcpus: add file to show isolated cpus in cpuset Date: Mon, 9 Mar 2015 12:12:09 -0400 Message-ID: <1425917530-1771-4-git-send-email-riel@redhat.com> References: <1425917530-1771-1-git-send-email-riel@redhat.com> Return-path: In-Reply-To: <1425917530-1771-1-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: tj@kernel.org Cc: linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, lizefan@huawei.com, Rik van Riel , Peter Zijlstra , Clark Williams , Ingo Molnar , Luiz Capitulino , David Rientjes , Mike Galbraith 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. Acked-by: David Rientjes Cc: Peter Zijlstra Cc: Clark Williams Cc: Li Zefan Cc: Ingo Molnar Cc: Luiz Capitulino Cc: David Rientjes Cc: Mike Galbraith Cc: cgroups@vger.kernel.org Signed-off-by: Rik van Riel --- 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); -- 2.1.0