Re: [PATCH] mm/percpu.c: use smarter memory allocation for struct pcpu_alloc_info

From: Dennis Zhou
Date: Tue Oct 03 2017 - 19:48:39 EST

Hi Tejun,

On Tue, Oct 03, 2017 at 03:36:42PM -0700, Tejun Heo wrote:
> > Subject: [PATCH] percpu: don't forget to free the temporary struct pcpu_alloc_info
> So, IIRC, the error path is either boot fail or some serious bug in
> arch code. It really doesn't matter whether we free a page or not.

In setup_per_cpu_area, a call to either pcpu_embed_first_chunk,
pcpu_page_first_chunk, or pcpu_setup_first_chunk is made. The first two
eventually call pcpu_setup_first_chunk with a pairing call to
pcpu_free_alloc_info right after. This occurs in all implementations. It
happens we don't have a pairing call to pcpu_free_alloc_info in the UP