Re: [PATCH v8 0/2] Directed kmem charging

[Andrew Morton]

On Wed, 27 Jun 2018 12:12:48 -0700 Shakeel Butt <shakeelb@xxxxxxxxxx> wrote:

> The Linux kernel's memory cgroup allows limiting the memory usage of
> the jobs running on the system to provide isolation between the jobs.
> All the kernel memory allocated in the context of the job and marked
> with __GFP_ACCOUNT will also be included in the memory usage and be
> limited by the job's limit.
> 
> The kernel memory can only be charged to the memcg of the process in
> whose context kernel memory was allocated. However there are cases where
> the allocated kernel memory should be charged to the memcg different
> from the current processes's memcg. This patch series contains two such
> concrete use-cases i.e. fsnotify and buffer_head.
> 
> The fsnotify event objects can consume a lot of system memory for large
> or unlimited queues if there is either no or slow listener. The events
> are allocated in the context of the event producer. However they should
> be charged to the event consumer. Similarly the buffer_head objects can
> be allocated in a memcg different from the memcg of the page for which
> buffer_head objects are being allocated.
> 
> To solve this issue, this patch series introduces mechanism to charge
> kernel memory to a given memcg. In case of fsnotify events, the memcg of
> the consumer can be used for charging and for buffer_head, the memcg of
> the page can be charged. For directed charging, the caller can use the
> scope API memalloc_[un]use_memcg() to specify the memcg to charge for
> all the __GFP_ACCOUNT allocations within the scope.

This patchset is not showing signs of having been well reviewed at
this time.  Could people please take another look?