Re: [PATCH RFC] ipmi: use vzalloc instead of kmalloc for user creation
From: Corey Minyard
Date: Fri Apr 17 2020 - 22:00:25 EST
On Fri, Apr 17, 2020 at 01:01:29PM +0800, Feng Tang wrote:
> We met mulitple times of failure of staring bmc-watchdog,
> due to the runtime memory allocation failure of order 4.
I'm beginning to think that using srcu was a bad idea. It made things
cleaner and easier, but it eats tons of memory. Sigh.
Applied, at least for a fix for now.
Thanks,
-corey
>
> bmc-watchdog: page allocation failure: order:4, mode:0x40cc0(GFP_KERNEL|__GFP_COMP), nodemask=(null),cpuset=/,mems_allowed=0-1
> CPU: 1 PID: 2571 Comm: bmc-watchdog Not tainted 5.5.0-00045-g7d6bb61d6188c #1
> Hardware name: Intel Corporation S2600WFT/S2600WFT, BIOS SE5C620.86B.00.01.0015.110720180833 11/07/2018
> Call Trace:
> dump_stack+0x66/0x8b
> warn_alloc+0xfe/0x160
> __alloc_pages_slowpath+0xd3e/0xd80
> __alloc_pages_nodemask+0x2f0/0x340
> kmalloc_order+0x18/0x70
> kmalloc_order_trace+0x1d/0xb0
> ipmi_create_user+0x55/0x2c0 [ipmi_msghandler]
> ipmi_open+0x72/0x110 [ipmi_devintf]
> chrdev_open+0xcb/0x1e0
> do_dentry_open+0x1ce/0x380
> path_openat+0x305/0x14f0
> do_filp_open+0x9b/0x110
> do_sys_open+0x1bd/0x250
> do_syscall_64+0x5b/0x1f0
> entry_SYSCALL_64_after_hwframe+0x44/0xa9
>
> Using vzalloc/vfree for creating ipmi_user heals the
> problem.
>
> Signed-off-by: Feng Tang <feng.tang@xxxxxxxxx>
> ---
> drivers/char/ipmi/ipmi_msghandler.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c
> index c48d8f0..96f1573 100644
> --- a/drivers/char/ipmi/ipmi_msghandler.c
> +++ b/drivers/char/ipmi/ipmi_msghandler.c
> @@ -1153,7 +1153,7 @@ static void free_user_work(struct work_struct *work)
> remove_work);
>
> cleanup_srcu_struct(&user->release_barrier);
> - kfree(user);
> + vfree(user);
> }
>
> int ipmi_create_user(unsigned int if_num,
> @@ -1185,7 +1185,7 @@ int ipmi_create_user(unsigned int if_num,
> if (rv)
> return rv;
>
> - new_user = kmalloc(sizeof(*new_user), GFP_KERNEL);
> + new_user = vzalloc(sizeof(*new_user));
> if (!new_user)
> return -ENOMEM;
>
> @@ -1232,7 +1232,7 @@ int ipmi_create_user(unsigned int if_num,
>
> out_kfree:
> srcu_read_unlock(&ipmi_interfaces_srcu, index);
> - kfree(new_user);
> + vfree(new_user);
> return rv;
> }
> EXPORT_SYMBOL(ipmi_create_user);
> --
> 2.7.4
>