From mboxrd@z Thu Jan 1 00:00:00 1970 Received: by wa-out-1112.google.com with SMTP id m33so953113wag for ; Thu, 07 Jun 2007 21:41:45 -0700 (PDT) Message-ID: <787b0d920706072141s5a34ecb3n97007ad857ba4dc9@mail.gmail.com> Date: Fri, 8 Jun 2007 00:41:45 -0400 From: "Albert Cahalan" Subject: Re: [RFC][PATCH] /proc/pid/maps doesn't match "ipcs -m" shmid In-Reply-To: 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> <787b0d920706062153u7ad64179p1c4f3f663c3882f@mail.gmail.com> <20070607162004.GA27802@vino.hallyn.com> Sender: owner-linux-mm@kvack.org Return-Path: To: "Eric W. Biederman" Cc: "Serge E. Hallyn" , Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org, pbadari@us.ibm.com, torvalds@linux-foundation.org List-ID: On 6/7/07, Eric W. Biederman wrote: > So it looks to me like we need to do three things: > - Fix the inode number > - Fix the name on the hugetlbfs dentry to hold the key > - Add a big fat comment that user space programs depend on this > behavior of both the dentry name and the inode number. Assuming that this proposed fix goes in: Since the inode number is the shmid, and this is a number that the kernel randomly chooses AFAIK, there should be no need to have different shm segments sharing the same inode number. The situation with the key is a bit more disturbing, though we already hit that anyway when IPC_PRIVATE is used. (why anybody would NOT use IPC_PRIVATE is a mystery) So having the key in the name doesn't make things worse. I have some concern about the device minor number. This should be the same for all shm mappings; I do not know if the behavior changed. -- 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