CODEWITHSUNDEEP
linuxmodulelinux-kernel
Ravi
Ravi

Reputation: 249

Meaning of module's instances in /proc/modules

I have used cat /proc/modules to list the modules details.

Below a module shows as 4 instances are present:

poe_isr 3046 4 - Live 0xc37e1000 (O)

What does it mean? How do I see where these instances are being used?

Next module is showing as 0 instances and Live:

adcmods 1565 0 - Live 0xc37dd000 (P)

What does it mean? The module is not loaded but still Live?

Upvotes: 2

Views: 4409

Answers (1)

Tsyvarev
Tsyvarev

Reputation: 65928

Not sure why some descriptions (like this one) name the third column of /proc/modules output as a "number of instances", but this is actually a module's reference count.

If a module has a positive (non-zero) reference count, then it cannot be unloaded with /sbin/rmmod (the command prints "ERROR: Module X is in use").

If some module's references are obtained by other modules, then a comma-separated list of these modules is printed as 4th column (instead of - character).

If the module's reference is obtained by non-module "objects", one should use other methods for listing these objects. E.g. a filesystem module is normally referenced by the filesystem's mounts, so one needs to check output of /usr/bin/mount.

Upvotes: 7

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