Unexpected crash in alsa. Can someone explain this?
by hazel from LinuxQuestions.org on (#5CW5W)
I don't understand audio but I am increasingly obliged to use audio software to help with the online operations of my parish church. I have alsa-utils and I have recently installed sox on the advice of someone here; I must say I am greatly impressed with what it can apparently do.
I am trying to use alsamixer to improve my sound recording quality, but I don't understand audio terminology, so the man pages and display captions are about as informative for me as if they were written in a foreign language. So I decided to just try modifying one alsamixer column at a time to see what the effect would be on a test recording. That way, I hoped, I could find out what the captions actually mean.
Then suddenly alsa went on strike. Every attempt to record produced this:
Code:ALSA lib pcm_dsnoop.c:589:(snd_pcm_dsnoop_open) unable to create IPC shm instance
arecord: main:786: audio open error: Cannot allocate memoryI ran top and that didn't suggest any great demands on memory. All the same, I shut down everything else and tried again. Nothing doing!
Googling the error produced only references to an occasional bug that had been cleared up, and to someone using Fedora who got that error only when he used audio as an unprivileged user. Just to check, I did it again as root and got the same result. So I shut down in disgust.
This morning everything works normally, but for how long? What did I do to create that error? And what should I do to stop it happening again?
I am trying to use alsamixer to improve my sound recording quality, but I don't understand audio terminology, so the man pages and display captions are about as informative for me as if they were written in a foreign language. So I decided to just try modifying one alsamixer column at a time to see what the effect would be on a test recording. That way, I hoped, I could find out what the captions actually mean.
Then suddenly alsa went on strike. Every attempt to record produced this:
Code:ALSA lib pcm_dsnoop.c:589:(snd_pcm_dsnoop_open) unable to create IPC shm instance
arecord: main:786: audio open error: Cannot allocate memoryI ran top and that didn't suggest any great demands on memory. All the same, I shut down everything else and tried again. Nothing doing!
Googling the error produced only references to an occasional bug that had been cleared up, and to someone using Fedora who got that error only when he used audio as an unprivileged user. Just to check, I did it again as root and got the same result. So I shut down in disgust.
This morning everything works normally, but for how long? What did I do to create that error? And what should I do to stop it happening again?