diff options
| -rw-r--r-- | kernel/kmod.c | 16 | ||||
| -rw-r--r-- | tools/testing/selftests/kmod/kmod.sh | 24 |
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() { |