Re: 2.6 /proc/interrupts fails on systems with many CPUs

["Randy.Dunlap" <rddunlap@osdl.org>]

On Tue, 11 Nov 2003 10:17:47 -0800 (PST) Linus Torvalds <torvalds@osdl.org> wrote:

| 
| On Tue, 11 Nov 2003, Erik Jacobson wrote:
| > 
| > I'm looking for suggestions on how to fix this.  I came up with one fix
| > that seems to work OK for ia64.  I have attached it to this message.
| > I'm looking for advice on what should be proposed for the real fix.
| 
| This is not the real fix.
| 
| Allowing people to use up vmalloc() space by opening the /proc files would 
| be a major DoS attack. Not worth it.
| 
| Instead, just make /proc/interrupts use the proper _sequence_ things, so
| that instead of trying to print out everything in one go, you have the
| "s_next()" thing to print them out one at a time. The seqfile interfaces
| will then do the rigth thing with blocking/caching, and you only need a
| single page.
| 
| Al - do we have some good documentation of how to use the seq-file 
| interface? 

See  http://lwn.net/Articles/22355/
and  http://www.xenotime.net/linux/doc/seq_file_howto.txt

| In the meantime, without documentation, the best place to look is just at 
| other examples. One such example would be the kernel/kallsyms.c case: see 
| how it does s_start/s_show/s_next/s_stop (or /proc/slabinfo, or vmstat, or 
| any number of them).


--
~Randy
MOTD:  Always include version info.