Re: [-mm][PATCH 4/4] Add memrlimit controller accounting and control (v4)

[Pavel Emelyanov <xemul@openvz.org>]

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(). There are some special
> cases that are handled here as well (arch/ia64/kernel/perform.c,
> arch/x86/kernel/ptrace.c, insert_special_mapping())
> 
> Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com>
> ---
> 
> Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com>
> ---
> 
>  arch/ia64/kernel/perfmon.c      |    6 ++
>  arch/x86/kernel/ptrace.c        |   17 +++++--
>  fs/exec.c                       |    5 ++
>  include/linux/memrlimitcgroup.h |   21 ++++++++
>  kernel/fork.c                   |    8 +++
>  mm/memrlimitcgroup.c            |   94 ++++++++++++++++++++++++++++++++++++++++
>  mm/mmap.c                       |   11 ++++
>  7 files changed, 157 insertions(+), 5 deletions(-)
> 
> diff -puN arch/ia64/kernel/perfmon.c~memrlimit-controller-address-space-accounting-and-control arch/ia64/kernel/perfmon.c
> --- linux-2.6.26-rc2/arch/ia64/kernel/perfmon.c~memrlimit-controller-address-space-accounting-and-control	2008-05-14 18:09:32.000000000 +0530
> +++ linux-2.6.26-rc2-balbir/arch/ia64/kernel/perfmon.c	2008-05-14 18:09:32.000000000 +0530
> @@ -40,6 +40,7 @@
>  #include <linux/capability.h>
>  #include <linux/rcupdate.h>
>  #include <linux/completion.h>
> +#include <linux/memrlimitcgroup.h>
>  
>  #include <asm/errno.h>
>  #include <asm/intrinsics.h>
> @@ -2294,6 +2295,9 @@ pfm_smpl_buffer_alloc(struct task_struct
>  
>  	DPRINT(("sampling buffer rsize=%lu size=%lu bytes\n", rsize, size));
>  
> +	if (memrlimit_cgroup_charge_as(mm, size >> PAGE_SHIFT))
> +		return -ENOMEM;
> +

AFAIS you didn't cover all the cases when VM expands. At least all
the arch/ia64/ia32/binfmt_elf32.c is missed.

I'd insert this charge into insert_vm_struct. This would a) cover
all of the missed cases and b) reduce the amount of places to patch.

[snip the rest of the patch]