Re: [Qemu-devel] [PATCH] fix the memory leak for share hugepage

[zhanghailiang <zhang.zhanghailiang@huawei.com>]

On 2014/10/17 16:27, haifeng.lin@huawei.com wrote:
> From: linhaifeng <haifeng.lin@huawei.com>
>
> The VM start with share hugepage should close the hugefile fd
> when exit.Because the hugepage fd may be send to other process
> e.g vhost-user If qemu not close the fd the other process can
> not free the hugepage otherwise exit process,this is ugly,so
> qemu should close all shared fd when exit.
>
> Signed-off-by: linhaifeng <haifeng.lin@huawei.com>
> ---
>   exec.c | 12 ++++++++++++
>   vl.c   |  7 +++++++
>   2 files changed, 19 insertions(+)
>
> diff --git a/exec.c b/exec.c
> index 759055d..d120b73 100644
> --- a/exec.c
> +++ b/exec.c
> @@ -1535,6 +1535,18 @@ void qemu_ram_remap(ram_addr_t addr, ram_addr_t length)
>           }
>       }
>   }
> +
> +void qemu_close_all_ram_fd(void)
> +{
> +    RAMBlock *block;
> +
> +    qemu_mutex_lock_ramlist();
> +    QTAILQ_FOREACH(block, &ram_list.blocks, next) {
> +        close(block->fd);
> +    }
> +    qemu_mutex_unlock_ramlist();
> +}
> +
>   #endif /* !_WIN32 */
>
>   int qemu_get_ram_fd(ram_addr_t addr)
> diff --git a/vl.c b/vl.c
> index aee73e1..0b78f3f 100644
> --- a/vl.c
> +++ b/vl.c
> @@ -1658,6 +1658,7 @@ static int qemu_shutdown_requested(void)
>       return r;
>   }
>
> +extern void qemu_close_all_ram_fd(void);
>   static void qemu_kill_report(void)
>   {
>       if (!qtest_driver() && shutdown_signal != -1) {
> @@ -1671,6 +1672,12 @@ static void qemu_kill_report(void)
>               fprintf(stderr, " from pid " FMT_pid "\n", shutdown_pid);
>           }
>           shutdown_signal = -1;
> +
> +        /* Close all ram fd when exit. If the ram is shared by othter process

s/othter/other/

> +         * e.g vhost-user, it can free the hugepage by close fd after qemu exit,
> +         * otherwise the process have to exit to free hugepage.
> +         */
> +        qemu_close_all_ram_fd();
>       }
>   }
>
>