+++ /dev/null
-From 5de7c318804a7b1edce8562d4891b4c74aac0677 Mon Sep 17 00:00:00 2001
-From: Michael Jeanson <mjeanson@efficios.com>
-Date: Wed, 20 Mar 2019 11:07:35 -0400
-Subject: [PATCH] compat: work around broken _SC_NPROCESSORS_CONF on MUSL libc
-
-On MUSL libc the _SC_NPROCESSORS_CONF sysconf will report the number of
-CPUs allocated to the task based on the affinity mask instead of the
-total number of CPUs configured on the system.
-
-Upstream-Status: Accepted [1] [5de7c318804a7b1edce8562d4891b4c74aac0677]
-[1] https://lists.lttng.org/pipermail/lttng-dev/2019-March/028616.html
-
-Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
-Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
----
- libringbuffer/smp.c | 66 +++++++++++++++++++++++++++++++++++++++++++++
- 1 file changed, 66 insertions(+)
-
-diff --git a/libringbuffer/smp.c b/libringbuffer/smp.c
-index 9e7114be..656a75da 100644
---- a/libringbuffer/smp.c
-+++ b/libringbuffer/smp.c
-@@ -2,6 +2,7 @@
- * libringbuffer/smp.c
- *
- * Copyright (C) 2011-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
-+ * Copyright (C) 2019 Michael Jeanson <mjeanson@efficios.com>
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
-@@ -26,6 +27,7 @@
-
- int __num_possible_cpus;
-
-+#if (defined(__GLIBC__) || defined( __UCLIBC__))
- void _get_num_possible_cpus(void)
- {
- int result;
-@@ -43,3 +45,67 @@ void _get_num_possible_cpus(void)
- return;
- __num_possible_cpus = result;
- }
-+
-+#else
-+
-+/*
-+ * The MUSL libc implementation of the _SC_NPROCESSORS_CONF sysconf does not
-+ * return the number of configured CPUs in the system but relies on the cpu
-+ * affinity mask of the current task.
-+ *
-+ * So instead we use a strategy similar to GLIBC's, counting the cpu
-+ * directories in "/sys/devices/system/cpu" and fallback on the value from
-+ * sysconf if it fails.
-+ */
-+
-+#include <dirent.h>
-+#include <limits.h>
-+#include <stdlib.h>
-+#include <string.h>
-+#include <sys/types.h>
-+
-+#define __max(a,b) ((a)>(b)?(a):(b))
-+
-+void _get_num_possible_cpus(void)
-+{
-+ int result, count = 0;
-+ DIR *cpudir;
-+ struct dirent *entry;
-+
-+ cpudir = opendir("/sys/devices/system/cpu");
-+ if (cpudir == NULL)
-+ goto end;
-+
-+ /*
-+ * Count the number of directories named "cpu" followed by and
-+ * integer. This is the same strategy as glibc uses.
-+ */
-+ while ((entry = readdir(cpudir))) {
-+ if (entry->d_type == DT_DIR &&
-+ strncmp(entry->d_name, "cpu", 3) == 0) {
-+
-+ char *endptr;
-+ unsigned long cpu_num;
-+
-+ cpu_num = strtoul(entry->d_name + 3, &endptr, 10);
-+ if ((cpu_num < ULONG_MAX) && (endptr != entry->d_name + 3)
-+ && (*endptr == '\0')) {
-+ count++;
-+ }
-+ }
-+ }
-+
-+end:
-+ /*
-+ * Get the sysconf value as a fallback. Keep the highest number.
-+ */
-+ result = __max(sysconf(_SC_NPROCESSORS_CONF), count);
-+
-+ /*
-+ * If both methods failed, don't store the value.
-+ */
-+ if (result < 1)
-+ return;
-+ __num_possible_cpus = result;
-+}
-+#endif
---
-2.17.1
-
