2002-08-30 21:11:30

by Anton Lavrentiev

Subject: Re: BUG:: SYSV IPC shmem reported as "(deleted)" in process maps file

Dear Linux Developers:

/proc/#/maps file of a process, which has a shared memory segment attached,
prints the segment as "(deleted)" while in fact the segment is fine and sound.
This seems to be quite confusing.

cat /proc/#/maps:
40018000-40022000 rw-s 00000000 00:05 5865476 /SYSV01315549 (deleted)
4021b000-40225000 rw-s 00000000 00:05 5898248 /SYSV012cc3bc (deleted)

ipcs -a:
0x01315549 5865476 ncbiduse 666 40960 1
0x012cc3bc 5898248 ncbiduse 666 40960 1

Best regards,

Anton Lavrentiev
NCBI/NLM/NIH
Bethesda MD 20894

2002-09-05 17:04:06

by Christoph Rohland

Subject: Re: BUG:: SYSV IPC shmem reported as "(deleted)" in process maps file

Hi Anton,

On Fri, 30 Aug 2002, Anton Lavrentiev wrote:
> cat /proc/#/maps:
> 40018000-40022000 rw-s 00000000 00:05 5865476 /SYSV01315549 (deleted)
> 4021b000-40225000 rw-s 00000000 00:05 5898248 /SYSV012cc3bc (deleted)
>
> ipcs -a:
> 0x01315549 5865476 ncbiduse 666 40960 1
> 0x012cc3bc 5898248 ncbiduse 666 40960 1

Works as designed.

The internal implementation creates the file unlinked. SYSV is one
holder of this open file. The display may be irritating but IMHO its
internal simplicity is worth to live with it.

Greetings
Christoph