At Tue, 16 Jul 2013 10:28:02 +0200, Philipp Hahn wrote:
Hello,
Am Dienstag 16 Juli 2013, 08:43:36 schrieb Takashi Iwai:
At Tue, 16 Jul 2013 15:11:51 +0930, Rusty Russell wrote:
Philipp Matthias Hahn pmhahn@pmhahn.de writes:
My x86_64 systems has some trouble loading some ALSA snd-* modules since the upgrade to 3.10.[01]: Several automatic modprobe calls hang, but loading snd-intel-hda and snd-audio-usb by hand still works.
Not a known problem to me, at least. Perhaps it's a dep loop somehow.
I remember that someone reported it being Debian specific snd-seq-oss loading stuff.
FYI: "oss-compat" is installed.
... 1071 ? S 0:00 sh -c /sbin/modprobe --ignore-install snd && { /sbin/modprobe --quiet snd 1080 ? D 0:00 _ /sbin/modprobe --quiet snd-seq
This was first, and it's waiting. Which means it must be doing something weird, because snd_seq_oss is loading now:
snd_seq_oss 33717 1 - Loading 0xffffffffa041b000
Perhaps in the tangle of modprobe install commands somewhere this gets invoked?
Likely, but I wonder what triggered a bug suddenly on 3.10. There is absolutely no change in sound/core/seq/*, and through a quick look, I couldn't find any suspicious change in kernel/module.c that may lead to this problem between 3.9 and 3.10.
Philipp, can you get a sysrq-T trace while the stall?
I've finally been able to reducte the number of processes to get a full trace; see attached file.
Please note that in this case the proprietary "nvidia" module was loaded, since I currently onyl have remove access to the machine. The original trace from yesterday happend without the nvidia module ever being loaded.
Am Dienstag 16 Juli 2013, 08:42:35 schrieb Lucas De Marchi:
On Tue, Jul 16, 2013 at 2:41 AM, Rusty Russell rusty@rustcorp.com.au wrote: First thing to check is the /etc/modprobe.d/*.conf file that contains these install commands. Did they change besides the kernel upgrade?
Not that I know of: Booting 3.9.9 works fine, 3.10.x shows the problem.
...
Philipp, which kernel are you upgrading from?
I just upgraded from 3.9.9 to 3.10.0; also tried 3.10.1 which did not improve the situation.
Could you check the patch below? It makes the code path involving with request_module asynchronous.
thanks,
Takashi
--- From: Takashi Iwai tiwai@suse.de Subject: [PATCH] ALSA: seq-oss: Initialize MIDI clients asynchronously
The recent report showed that the initial registration of OSS sequencer clients stuck at loading the sound modules, which involves with request_module() at the init phase. As a workaround, call the registration part asynchronously. (And, this is a better approache irrespective of the hang fix.)
Reported-by: Philipp Matthias Hahn pmhahn@pmhahn.de Cc: stable@vger.kernel.org Signed-off-by: Takashi Iwai tiwai@suse.de --- sound/core/seq/oss/seq_oss_init.c | 16 +++++++++++++--- sound/core/seq/oss/seq_oss_midi.c | 2 +- 2 files changed, 14 insertions(+), 4 deletions(-)
diff --git a/sound/core/seq/oss/seq_oss_init.c b/sound/core/seq/oss/seq_oss_init.c index e3cb46f..b3f39b5 100644 --- a/sound/core/seq/oss/seq_oss_init.c +++ b/sound/core/seq/oss/seq_oss_init.c @@ -31,6 +31,7 @@ #include <linux/export.h> #include <linux/moduleparam.h> #include <linux/slab.h> +#include <linux/workqueue.h>
/* * common variables @@ -60,6 +61,14 @@ static void free_devinfo(void *private); #define call_ctl(type,rec) snd_seq_kernel_client_ctl(system_client, type, rec)
+/* call snd_seq_oss_midi_lookup_ports() asynchronously */ +static void async_call_lookup_ports(struct work_struct *work) +{ + snd_seq_oss_midi_lookup_ports(system_client); +} + +static DECLARE_WORK(async_lookup_work, async_call_lookup_ports); + /* * create sequencer client for OSS sequencer */ @@ -85,9 +94,6 @@ snd_seq_oss_create_client(void) system_client = rc; debug_printk(("new client = %d\n", rc));
- /* look up midi devices */ - snd_seq_oss_midi_lookup_ports(system_client); - /* create annoucement receiver port */ memset(port, 0, sizeof(*port)); strcpy(port->name, "Receiver"); @@ -115,6 +121,9 @@ snd_seq_oss_create_client(void) } rc = 0;
+ /* look up midi devices */ + schedule_work(&async_lookup_work); + __error: kfree(port); return rc; @@ -160,6 +169,7 @@ receive_announce(struct snd_seq_event *ev, int direct, void *private, int atomic int snd_seq_oss_delete_client(void) { + cancel_work_sync(&async_lookup_work); if (system_client >= 0) snd_seq_delete_kernel_client(system_client);
diff --git a/sound/core/seq/oss/seq_oss_midi.c b/sound/core/seq/oss/seq_oss_midi.c index 677dc84..862d8489 100644 --- a/sound/core/seq/oss/seq_oss_midi.c +++ b/sound/core/seq/oss/seq_oss_midi.c @@ -72,7 +72,7 @@ static int send_midi_event(struct seq_oss_devinfo *dp, struct snd_seq_event *ev, * look up the existing ports * this looks a very exhausting job. */ -int __init +int snd_seq_oss_midi_lookup_ports(int client) { struct snd_seq_client_info *clinfo;