Re: [patch 1/2] arch: invoke oom-killer from page fault

[刘胜蛟 <liushengjiao@gmail.com>]

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www.all-sky.com


2013/6/6 Johannes Weiner <hannes@cmpxchg.org>

> Since '1c0fe6e mm: invoke oom-killer from page fault', page fault
> handlers should not directly kill faulting tasks in an out of memory
> condition.  Instead, they should be invoking the OOM killer to pick
> the right task.  Convert the remaining architectures.
>
> Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
> ---
>  arch/arc/mm/fault.c      | 6 ++++--
>  arch/metag/mm/fault.c    | 6 ++++--
>  arch/mn10300/mm/fault.c  | 7 ++++---
>  arch/openrisc/mm/fault.c | 8 ++++----
>  arch/score/mm/fault.c    | 8 ++++----
>  arch/tile/mm/fault.c     | 8 ++++----
>  6 files changed, 24 insertions(+), 19 deletions(-)
>
> diff --git a/arch/arc/mm/fault.c b/arch/arc/mm/fault.c
> index c0decc1..d5ec60a 100644
> --- a/arch/arc/mm/fault.c
> +++ b/arch/arc/mm/fault.c
> @@ -207,8 +207,10 @@ out_of_memory:
>         }
>         up_read(&mm->mmap_sem);
>
> -       if (user_mode(regs))
> -               do_group_exit(SIGKILL); /* This will never return */
> +       if (user_mode(regs)) {
> +               pagefault_out_of_memory();
> +               return;
> +       }
>
>         goto no_context;
>
> diff --git a/arch/metag/mm/fault.c b/arch/metag/mm/fault.c
> index 2c75bf7..8fddf46 100644
> --- a/arch/metag/mm/fault.c
> +++ b/arch/metag/mm/fault.c
> @@ -224,8 +224,10 @@ do_sigbus:
>          */
>  out_of_memory:
>         up_read(&mm->mmap_sem);
> -       if (user_mode(regs))
> -               do_group_exit(SIGKILL);
> +       if (user_mode(regs)) {
> +               pagefault_out_of_memory();
> +               return 1;
> +       }
>
>  no_context:
>         /* Are we prepared to handle this kernel fault?  */
> diff --git a/arch/mn10300/mm/fault.c b/arch/mn10300/mm/fault.c
> index d48a84f..8a2e6de 100644
> --- a/arch/mn10300/mm/fault.c
> +++ b/arch/mn10300/mm/fault.c
> @@ -345,9 +345,10 @@ no_context:
>   */
>  out_of_memory:
>         up_read(&mm->mmap_sem);
> -       printk(KERN_ALERT "VM: killing process %s\n", tsk->comm);
> -       if ((fault_code & MMUFCR_xFC_ACCESS) == MMUFCR_xFC_ACCESS_USR)
> -               do_exit(SIGKILL);
> +       if ((fault_code & MMUFCR_xFC_ACCESS) == MMUFCR_xFC_ACCESS_USR) {
> +               pagefault_out_of_memory();
> +               return;
> +       }
>         goto no_context;
>
>  do_sigbus:
> diff --git a/arch/openrisc/mm/fault.c b/arch/openrisc/mm/fault.c
> index e2bfafc..4a41f84 100644
> --- a/arch/openrisc/mm/fault.c
> +++ b/arch/openrisc/mm/fault.c
> @@ -267,10 +267,10 @@ out_of_memory:
>         __asm__ __volatile__("l.nop 1");
>
>         up_read(&mm->mmap_sem);
> -       printk("VM: killing process %s\n", tsk->comm);
> -       if (user_mode(regs))
> -               do_exit(SIGKILL);
> -       goto no_context;
> +       if (!user_mode(regs))
> +               goto no_context;
> +       pagefault_out_of_memory();
> +       return;
>
>  do_sigbus:
>         up_read(&mm->mmap_sem);
> diff --git a/arch/score/mm/fault.c b/arch/score/mm/fault.c
> index 47b600e..6b18fb0 100644
> --- a/arch/score/mm/fault.c
> +++ b/arch/score/mm/fault.c
> @@ -172,10 +172,10 @@ out_of_memory:
>                 down_read(&mm->mmap_sem);
>                 goto survive;
>         }
> -       printk("VM: killing process %s\n", tsk->comm);
> -       if (user_mode(regs))
> -               do_group_exit(SIGKILL);
> -       goto no_context;
> +       if (!user_mode(regs))
> +               goto no_context;
> +       pagefault_out_of_memory();
> +       return;
>
>  do_sigbus:
>         up_read(&mm->mmap_sem);
> diff --git a/arch/tile/mm/fault.c b/arch/tile/mm/fault.c
> index 3d2b81c..f7f99f9 100644
> --- a/arch/tile/mm/fault.c
> +++ b/arch/tile/mm/fault.c
> @@ -573,10 +573,10 @@ out_of_memory:
>                 down_read(&mm->mmap_sem);
>                 goto survive;
>         }
> -       pr_alert("VM: killing process %s\n", tsk->comm);
> -       if (!is_kernel_mode)
> -               do_group_exit(SIGKILL);
> -       goto no_context;
> +       if (is_kernel_mode)
> +               goto no_context;
> +       pagefault_out_of_memory();
> +       return 0;
>
>  do_sigbus:
>         up_read(&mm->mmap_sem);
> --
> 1.8.2.3
>
> --
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