From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Wed, 21 May 2008 21:24:08 -0700 From: Andrew Morton Subject: Re: [-mm][PATCH 4/4] Add memrlimit controller accounting and control (v5) Message-Id: <20080521212408.6f535259.akpm@linux-foundation.org> In-Reply-To: <20080521153012.15001.96490.sendpatchset@localhost.localdomain> References: <20080521152921.15001.65968.sendpatchset@localhost.localdomain> <20080521153012.15001.96490.sendpatchset@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Balbir Singh Cc: linux-mm@kvack.org, Sudhir Kumar , YAMAMOTO Takashi , Paul Menage , lizf@cn.fujitsu.com, linux-kernel@vger.kernel.org, Pavel Emelianov , KAMEZAWA Hiroyuki List-ID: On Wed, 21 May 2008 21:00:12 +0530 Balbir Singh wrote: > > This patch adds support for accounting and control of virtual address space > limits. The accounting is done via the rlimit_cgroup_(un)charge_as functions. > The core of the accounting takes place during fork time in copy_process(), > may_expand_vm(), remove_vma_list() and exit_mmap(). > > Changelog v5->v4 > > Move specific hooks in code to insert_vm_struct > Use mmap_sem to protect mm->owner from changing and mm->owner from > changing cgroups. > > ... > > + * brk(), sbrk()), stack expansion, mremap(), etc - called with > + * mmap_sem held. > + * decreasing - called with mmap_sem held. > + * This callback is called with mmap_sem held It's good to document the locking prerequisites but for rwsems, one should specify whether it must be held for reading or for writing. Of course, down_write() is a superset of down_read(), so if it's "held for reading" then either mode-of-holding is OK. But it's best to spell all that out. -- 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