Re: [PATCH 1/9] memcg: accounting for allocations called with disabled BH

[Vasily Averin <vvs@virtuozzo.com>]

On 3/9/21 5:57 PM, Michal Hocko wrote:
> On Tue 09-03-21 11:03:48, Vasily Averin wrote:
>> in_interrupt() check in memcg_kmem_bypass() is incorrect because
>> it does not allow to account memory allocation called from task context
>> with disabled BH, i.e. inside spin_lock_bh()/spin_unlock_bh() sections
> 
> Is there any existing user in the tree? Or is this more of a preparatory
> patch for a later one which will need it? In other words, is this a bug
> fix or a preparatory work.

struct fib6_node objects are allocated by this way
net/ipv6/route.c::__ip6_ins_rt()
...        write_lock_bh(&table->tb6_lock);
        err = fib6_add(&table->tb6_root, rt, info, mxc);
        write_unlock_bh(&table->tb6_lock);

I spend some time to understand why properly entries from properly configured cache
was not accounted to container's memcg.

Thank you,
	Vasily Averin