http://bugzilla.novell.com/show_bug.cgi?id=562232 http://bugzilla.novell.com/show_bug.cgi?id=562232#c1 Greg Kroah-Hartman changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |RESOLVED Resolution| |INVALID --- Comment #1 from Greg Kroah-Hartman 2009-12-10 22:56:42 UTC --- Yes, you don't have enough memory to do this with a kernel image that contains all debugging symbols and a very large number of kernel modules. Either turn off kernel debugging, or don't build all of those kernel modules, or get some more memory for your system. Anyway, this isn't a kernel error, nothing we can do about it, sorry. -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.

http://bugzilla.novell.com/show_bug.cgi?id=562232 http://bugzilla.novell.com/show_bug.cgi?id=562232#c3 Michal Marek changed: What |Removed |Added ---------------------------------------------------------------------------- Status|REOPENED |NEEDINFO Info Provider| |Flavio@Flavioweb.it --- Comment #3 from Michal Marek 2009-12-15 15:17:45 UTC --- Can you post the output of 'ulimit -a'? If you set some strict limit on virtual memory, then depmod can't do much about it. If that's not the case, please attach the output of # strace -o strace /sbin/depmod 2.6.31.5-0.1-flavioweb -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.

http://bugzilla.novell.com/show_bug.cgi?id=562232 http://bugzilla.novell.com/show_bug.cgi?id=562232#c5 --- Comment #5 from Michal Marek 2009-12-15 20:51:10 UTC --- So you have a limit of about 712MB on virtual memory. How much space do the modules with debuginfo take up? Try du -sh /lib/modules/2.6.31.5-0.1-flavioweb If it approaches the 712MB limit, then you need to increase it (depmod doesn't _allocate_ much memory, but it needs to mmap() the *.ko files, which counts as virtual memory usage). -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.

http://bugzilla.novell.com/show_bug.cgi?id=562232 http://bugzilla.novell.com/show_bug.cgi?id=562232#c7 Michal Marek changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEEDINFO |RESOLVED Info Provider|Flavio@Flavioweb.it | Resolution| |INVALID --- Comment #7 from Michal Marek 2009-12-16 11:34:19 UTC --- (In reply to comment #6)

du -sh /lib/modules/2.6.31.5-0.1-flavioweb 90M /lib/modules/2.6.31.5-0.1-flavioweb

Now I'm confused. Is this the same kernel that you encountered the bug with or did you rebuild w/o debuginfo in the meantime?

It's possible that "debug info" on modules take up 622 MB ???

That's indeed possible yes (the 11.2 kernel-default-debuginfo package takes about 850MB). I suggest you just lift the virtual memory limit, depmod won't eat much memory, but it needs to mmap() all the *.ko files. -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.

http://bugzilla.novell.com/show_bug.cgi?id=562232 http://bugzilla.novell.com/show_bug.cgi?id=562232#c9 --- Comment #9 from Michal Marek 2009-12-16 12:06:58 UTC --- (In reply to comment #8)

(In reply to comment #7)

...

I suggest you just lift the virtual memory limit, depmod won't eat much memory, but it needs to mmap() all the *.ko files.

So i need a bigger swap partition on disk, or there are some other things to do for lift the virtual memory limit?

No, as I wrote, depmod doesn't allocate much memory, but the file mappings count as virtual memory.

Just a curiosity: why installing precompiled kernel and modules from rpms works fine, and not work compiling from source?

Packages have the debuginfo split off into $package-debuginfo.rpm. -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.

http://bugzilla.novell.com/show_bug.cgi?id=562232 http://bugzilla.novell.com/show_bug.cgi?id=562232#c11 Michal Marek changed: What |Removed |Added ---------------------------------------------------------------------------- Status|REOPENED |RESOLVED CC| |mmarek@novell.com Component|Kernel |Basesystem Resolution| |INVALID AssignedTo|kernel-maintainers@forge.pr |mmarek@novell.com |ovo.novell.com | --- Comment #11 from Michal Marek 2009-12-16 21:18:51 UTC --- Care to read the previous comments? depmod (at least in the openSUSE module-init-tools package) allocates a few megabytes of "ram". But it needs to mmap the *.ko files, which adds to the virtual memory usage. Hence if you have a low virtual memory limit (ulimit -v) and compile a kernel with CONFIG_DEBUG_INFO=y, it will easily hit the limit. -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.

http://bugzilla.novell.com/show_bug.cgi?id=562232 http://bugzilla.novell.com/show_bug.cgi?id=562232#c13 --- Comment #13 from Michal Marek 2009-12-16 22:20:41 UTC --- One last try: If you mmap a file on disk, it does not affect your ram or swap. -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.

http://bugzilla.novell.com/show_bug.cgi?id=562232 http://bugzilla.novell.com/show_bug.cgi?id=562232#c15 --- Comment #15 from Jeff Mahoney 2009-12-17 15:12:22 UTC --- Michal did not suggest adding memory, he suggested changing your limit for virtual memory. They're not the same thing and virtual memory is not just another term for "swap" despite how MacOS and Windows have abused the term. Virtual memory is the address space associated with a program. Each program has it's own 32/64-bit address space, of which most of it is potentially usable. Much of it never is. It can be used by the program instructions, dynamic memory (like malloc), shared libraries, and mmap. Shared libraries can take up a considerable amount of your address space - but there is usually only a single copy in memory that is shared by all programs that need it. So for an easy example, every program running on your system right now probably uses libc. On my system, that is about 1.4M. I have about 200 processes running on my system, but that library will only ever take a maximum of 1.4 MB of memory. UNIX systems have a facility called mmap, which gives programmers the ability map files into the address space of the program and access them as if they were loaded from disk into a chunk of memory. The difference is that only the portions that are actually accessed ever get read in from disk. Shared libraries use this and only ever load the parts of the library that are actually needed. This happens automatically when the memory is accessed. So for my libc example where I said it loads a maximum of 1.4 MB, it's actually less than that. There are portions of the library that are needed for compatibility but are hardly ever actually used. That code never gets loaded from disk. For kernel modules, depmod really only needs the module headers and the symbol table. The debuginfo isn't used and is never loaded. That's why Michal is saying that while the modules on disk take up over 800 MB, depmod only ever allocates a few MB. That's all it's actually using and that's all that has ever been read in from disk. BUT for sake of argument, lets say it did read everything in, since this seems to be the core of the misunderstanding here. If the system ran low on memory, the memory used by the modules wouldn't get pushed out to swap. Swap is used when the kernel doesn't have any other way to restore the contents of the memory when it's needed again. Since the kernel modules are already on disk, in your file system, it can just reuse the memory without writing anything out and re-read them from the file system when it's needed again. Swap would never be touched. -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.

http://bugzilla.novell.com/show_bug.cgi?id=562232 http://bugzilla.novell.com/show_bug.cgi?id=562232#c17 --- Comment #17 from roland kletzing 2009-12-20 12:55:00 UTC --- i`d also like to thank you jeff for the real good explanation! never read such good one before! -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.