From: K Prateek Nayak Date: Fri, 20 Dec 2024 06:32:23 +0000 (+0000) Subject: sched/stats: Print domain name in /proc/schedstat X-Git-Tag: v6.14-rc1~184^2~17 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=011b3a14dc66c40066d08d60a768e14ede7ef351;p=thirdparty%2Flinux.git sched/stats: Print domain name in /proc/schedstat Currently, there does not exist a straightforward way to extract the names of the sched domains and match them to the per-cpu domain entry in /proc/schedstat other than looking at the debugfs files which are only visible after enabling "verbose" debug after commit 34320745dfc9 ("sched/debug: Put sched/domains files under the verbose flag") Since tools like `perf sched stats`[1] require displaying per-domain information in user friendly manner, display the names of sched domain, alongside their level in /proc/schedstat. Domain names also makes the /proc/schedstat data unambiguous when some of the cpus are offline. For example, on a 128 cpus AMD Zen3 machine where CPU0 and CPU64 are SMT siblings and CPU64 is offline: Before: cpu0 ... domain0 ... domain1 ... cpu1 ... domain0 ... domain1 ... domain2 ... After: cpu0 ... domain0 MC ... domain1 PKG ... cpu1 ... domain0 SMT ... domain1 MC ... domain2 PKG ... [1] https://lore.kernel.org/lkml/20241122084452.1064968-1-swapnil.sapkal@amd.com/ Signed-off-by: K Prateek Nayak Signed-off-by: Ravi Bangoria Signed-off-by: Swapnil Sapkal Signed-off-by: Peter Zijlstra (Intel) Tested-by: James Clark Link: https://lore.kernel.org/r/20241220063224.17767-6-swapnil.sapkal@amd.com --- diff --git a/kernel/sched/stats.c b/kernel/sched/stats.c index 802bd9398a2ef..5f563965976c6 100644 --- a/kernel/sched/stats.c +++ b/kernel/sched/stats.c @@ -138,7 +138,7 @@ static int show_schedstat(struct seq_file *seq, void *v) for_each_domain(cpu, sd) { enum cpu_idle_type itype; - seq_printf(seq, "domain%d %*pb", dcount++, + seq_printf(seq, "domain%d %s %*pb", dcount++, sd->name, cpumask_pr_args(sched_domain_span(sd))); for (itype = 0; itype < CPU_MAX_IDLE_TYPES; itype++) { seq_printf(seq, " %u %u %u %u %u %u %u %u %u %u %u",