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

[Baoquan He <bhe@redhat.com>]

On 11/28/23 at 11:31am, Shijie Huang wrote:
> 
> 在 2023/11/28 11:25, Baoquan He 写道:
> > 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?
> 
> No problem.  I will send out them later.

Thank, Shijie. Let's wait and see if Kazu has any comment about these.