From mboxrd@z Thu Jan 1 00:00:00 1970 Received: by nz-out-0506.google.com with SMTP id x7so389967nzc for ; Wed, 06 Jun 2007 21:53:20 -0700 (PDT) Message-ID: <787b0d920706062153u7ad64179p1c4f3f663c3882f@mail.gmail.com> Date: Thu, 7 Jun 2007 00:53:19 -0400 From: "Albert Cahalan" Subject: Re: [RFC][PATCH] /proc/pid/maps doesn't match "ipcs -m" shmid In-Reply-To: <20070606204432.b670a7b1.akpm@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <787b0d920706062027s5a8fd35q752f8da5d446afc@mail.gmail.com> <20070606204432.b670a7b1.akpm@linux-foundation.org> Sender: owner-linux-mm@kvack.org Return-Path: To: Andrew Morton Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, ebiederm@xmission.com, pbadari@us.ibm.com, torvalds@linux-foundation.org List-ID: On 6/6/07, Andrew Morton wrote: > On Wed, 6 Jun 2007 23:27:01 -0400 "Albert Cahalan" wrote: > > Eric W. Biederman writes: > > > Badari Pulavarty writes: > > > > >> Your recent cleanup to shm code, namely > > >> > > >> [PATCH] shm: make sysv ipc shared memory use stacked files > > >> > > >> took away one of the debugging feature for shm segments. > > >> Originally, shmid were forced to be the inode numbers and > > >> they show up in /proc/pid/maps for the process which mapped > > >> this shared memory segments (vma listing). That way, its easy > > >> to find out who all mapped this shared memory segment. Your > > >> patchset, took away the inode# setting. So, we can't easily > > >> match the shmem segments to /proc/pid/maps easily. (It was > > >> really useful in tracking down a customer problem recently). > > >> Is this done deliberately ? Anything wrong in setting this back ? > > > > > > Theoretically it makes the stacked file concept more brittle, > > > because it means the lower layers can't care about their inode > > > number. > > > > > > We do need something to tie these things together. > > > > > > So I suspect what makes most sense is to simply rename the > > > dentry SYSVID > > > > Please stop breaking things in /proc. The pmap command relys > > on the old behavior. > > What effect did this change have upon the pmap command? Details, please. > > > It's time to revert. > > Probably true, but we'd need to understand what the impact was. Very simply, pmap reports the shmid. albert 0 ~$ pmap `pidof X` | egrep -2 shmid 30050000 16384K rw-s- /dev/fb0 31050000 152K rw--- [ anon ] 31076000 384K rw-s- [ shmid=0x3f428000 ] 310d6000 384K rw-s- [ shmid=0x3f430001 ] 31136000 384K rw-s- [ shmid=0x3f438002 ] 31196000 384K rw-s- [ shmid=0x3f440003 ] 311f6000 384K rw-s- [ shmid=0x3f448004 ] 31256000 384K rw-s- [ shmid=0x3f450005 ] 312b6000 384K rw-s- [ shmid=0x3f460006 ] 31316000 384K rw-s- [ shmid=0x3f870007 ] 31491000 140K r---- /usr/share/fonts/type1/gsfonts/n021003l.pfb 3150e000 9496K rw--- [ anon ] -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org