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-rw-r--r--kernel/kmod.c16
-rw-r--r--tools/testing/selftests/kmod/kmod.sh24
2 files changed, 9 insertions, 31 deletions
diff --git a/kernel/kmod.c b/kernel/kmod.c
index ff68198fe83b..6d016c5d97c8 100644
--- a/kernel/kmod.c
+++ b/kernel/kmod.c
@@ -68,6 +68,7 @@ static DECLARE_RWSEM(umhelper_sem);
*/
#define MAX_KMOD_CONCURRENT 50
static atomic_t kmod_concurrent_max = ATOMIC_INIT(MAX_KMOD_CONCURRENT);
+static DECLARE_WAIT_QUEUE_HEAD(kmod_wq);
/*
modprobe_path is set via /proc/sys.
@@ -140,7 +141,6 @@ int __request_module(bool wait, const char *fmt, ...)
va_list args;
char module_name[MODULE_NAME_LEN];
int ret;
- static int kmod_loop_msg;
/*
* We don't allow synchronous module loading from async. Module
@@ -164,14 +164,11 @@ int __request_module(bool wait, const char *fmt, ...)
return ret;
if (atomic_dec_if_positive(&kmod_concurrent_max) < 0) {
- /* We may be blaming an innocent here, but unlikely */
- if (kmod_loop_msg < 5) {
- printk(KERN_ERR
- "request_module: runaway loop modprobe %s\n",
- module_name);
- kmod_loop_msg++;
- }
- return -ENOMEM;
+ pr_warn_ratelimited("request_module: kmod_concurrent_max (%u) close to 0 (max_modprobes: %u), for module %s, throttling...",
+ atomic_read(&kmod_concurrent_max),
+ MAX_KMOD_CONCURRENT, module_name);
+ wait_event_interruptible(kmod_wq,
+ atomic_dec_if_positive(&kmod_concurrent_max) >= 0);
}
trace_module_request(module_name, wait, _RET_IP_);
@@ -179,6 +176,7 @@ int __request_module(bool wait, const char *fmt, ...)
ret = call_modprobe(module_name, wait ? UMH_WAIT_PROC : UMH_WAIT_EXEC);
atomic_inc(&kmod_concurrent_max);
+ wake_up(&kmod_wq);
return ret;
}
diff --git a/tools/testing/selftests/kmod/kmod.sh b/tools/testing/selftests/kmod/kmod.sh
index 10196a62ed09..8cecae9a8bca 100644
--- a/tools/testing/selftests/kmod/kmod.sh
+++ b/tools/testing/selftests/kmod/kmod.sh
@@ -59,28 +59,8 @@ ALL_TESTS="$ALL_TESTS 0004:1:1"
ALL_TESTS="$ALL_TESTS 0005:10:1"
ALL_TESTS="$ALL_TESTS 0006:10:1"
ALL_TESTS="$ALL_TESTS 0007:5:1"
-
-# Disabled tests:
-#
-# 0008 x 150 - multithreaded - push kmod_concurrent over max_modprobes for request_module()"
-# Current best-effort failure interpretation:
-# Enough module requests get loaded in place fast enough to reach over the
-# max_modprobes limit and trigger a failure -- before we're even able to
-# start processing pending requests.
-ALL_TESTS="$ALL_TESTS 0008:150:0"
-
-# 0009 x 150 - multithreaded - push kmod_concurrent over max_modprobes for get_fs_type()"
-# Current best-effort failure interpretation:
-#
-# get_fs_type() requests modules using aliases as such the optimization in
-# place today to look for already loaded modules will not take effect and
-# we end up requesting a new module to load, this bumps the kmod_concurrent,
-# and in certain circumstances can lead to pushing the kmod_concurrent over
-# the max_modprobe limit.
-#
-# This test fails much easier than test 0008 since the alias optimizations
-# are not in place.
-ALL_TESTS="$ALL_TESTS 0009:150:0"
+ALL_TESTS="$ALL_TESTS 0008:150:1"
+ALL_TESTS="$ALL_TESTS 0009:150:1"
test_modprobe()
{