Re: [PATCH] crash_core: export vmemmap when CONFIG_SPARSEMEM_VMEMMAP is enabled

From: Baoquan He
Date: Mon Nov 27 2023 - 22:26:12 EST


On 11/27/23 at 11:18am, Shijie Huang wrote:
>
> 在 2023/11/27 10:51, Baoquan He 写道:
> > Hi,
> >
> > On 11/27/23 at 10:07am, Huang Shijie wrote:
> > > In memory_model.h, if CONFIG_SPARSEMEM_VMEMMAP is configed,
> > > kernel will use vmemmap to do the __pfn_to_page/page_to_pfn,
> > > and kernel will not use the "classic sparse" to do the
> > > __pfn_to_page/page_to_pfn.
> > >
> > > So export the vmemmap when CONFIG_SPARSEMEM_VMEMMAP is configed.
> > > This makes the user applications (crash, etc) get faster
> > > pfn_to_page/page_to_pfn operations too.
> > Are there Crash or makedupfile patches posted yet to make use of this?
>
> I have patches for Crash to use the 'vmemmap', but after this patch is
> merged, I will send it out.
>
> (I think Kazu will not merge a crash patch which depends on a kernel patch
> which is not merged.)

Maybe post these userspace patches too so that Kazu can evaluat if those
improvement is necessary?