Re: [PATCH v8 9/9] vmcore: support mmap() on /proc/vmcore

[Zhang Yanfei]

On 06/04/2013 11:34 PM, Maxim Uvarov wrote:
> 
> 
> 
> 2013/6/3 Atsushi Kumagai <kumagai-atsushi@xxxxxxxxxxxxxxxxx <mailto:kumagai-atsushi@xxxxxxxxxxxxxxxxx>>
> 
>     Hello Maxim,
> 
>     On Thu, 30 May 2013 14:30:01 +0400
>     Maxim Uvarov <muvarov@xxxxxxxxx <mailto:muvarov@xxxxxxxxx>> wrote:
> 
>     > 2013/5/30 Zhang Yanfei <zhangyanfei@xxxxxxxxxxxxxx <mailto:zhangyanfei@xxxxxxxxxxxxxx>>
>     >
>     > > On 05/30/2013 05:14 PM, Maxim Uvarov wrote:
>     > > >
>     > > >
>     > > >
>     > > > 2013/5/27 HATAYAMA Daisuke <d.hatayama@xxxxxxxxxxxxxx <mailto:d.hatayama@xxxxxxxxxxxxxx> <mailto:
>     > > d.hatayama@xxxxxxxxxxxxxx <mailto:d.hatayama@xxxxxxxxxxxxxx>>>
>     > > >
>     > > >     (2013/05/24 18:02), Maxim Uvarov wrote:
>     > > >
>     > > >
>     > > >
>     > > >
>     > > >         2013/5/24 Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx <mailto:akpm@xxxxxxxxxxxxxxxxxxxx> <mailto:
>     > > akpm@xxxxxxxxxxxxxxxxxxxx <mailto:akpm@xxxxxxxxxxxxxxxxxxxx>> <mailto:akpm@linux-foundation. <mailto:akpm@linux-foundation.>__org <mailto:
>     > > akpm@xxxxxxxxxxxxxxxxxxxx <mailto:akpm@xxxxxxxxxxxxxxxxxxxx>>>>
>     > > >
>     > > >
>     > > >             On Thu, 23 May 2013 14:25:48 +0900 HATAYAMA Daisuke <
>     > > d.hatayama@xxxxxxxxxxxxxx <mailto:d.hatayama@xxxxxxxxxxxxxx> <mailto:d.hatayama@xxxxxxxxxxxxxx <mailto:d.hatayama@xxxxxxxxxxxxxx>> <mailto:
>     > > d.hatayama@xxxxxxxxxxxxxxxx <mailto:d.hatayama@xxxxxxxxxxxxxx <mailto:d.hatayama@xxxxxxxxxxxxxx>>>> wrote:
>     > > >
>     > > >              > This patch introduces mmap_vmcore().
>     > > >              >
>     > > >              > Don't permit writable nor executable mapping even with
>     > > mprotect()
>     > > >              > because this mmap() is aimed at reading crash dump memory.
>     > > >              > Non-writable mapping is also requirement of
>     > > remap_pfn_range() when
>     > > >              > mapping linear pages on non-consecutive physical pages;
>     > > see
>     > > >              > is_cow_mapping().
>     > > >              >
>     > > >              > Set VM_MIXEDMAP flag to remap memory by remap_pfn_range
>     > > and by
>     > > >              > remap_vmalloc_range_pertial at the same time for a single
>     > > >              > vma. do_munmap() can correctly clean partially remapped
>     > > vma with two
>     > > >              > functions in abnormal case. See zap_pte_range(),
>     > > vm_normal_page() and
>     > > >              > their comments for details.
>     > > >              >
>     > > >              > On x86-32 PAE kernels, mmap() supports at most 16TB
>     > > memory only. This
>     > > >              > limitation comes from the fact that the third argument of
>     > > >              > remap_pfn_range(), pfn, is of 32-bit length on x86-32:
>     > > unsigned long.
>     > > >
>     > > >             More reviewing and testing, please.
>     > > >
>     > > >
>     > > >         Do you have git pull for both kernel and userland changes? I
>     > > would like to do some more testing on my machines.
>     > > >
>     > > >         Maxim.
>     > > >
>     > > >
>     > > >     Thanks! That's very helpful.
>     > > >
>     > > >     --
>     > > >     Thanks.
>     > > >     HATAYAMA, Daisuke
>     > > >
>     > > > Any update for this? Where can I checkout all sources?
>     > >
>     > > This series is now in Andrew Morton's -mm tree.
>     > >
>     > > Ok, and what about makedumpfile changes? Is it possible to fetch them from
>     > somewhere?
> 
>     You can fetch them from here, "mmap" branch is the change:
> 
>       git://git.code.sf.net/p/makedumpfile/code <http://git.code.sf.net/p/makedumpfile/code>
> 
>     And they will be merged into v1.5.4.
> 
> 
> thank you, got it. But still do not see kernel patches in akpm tree:
> git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
> http://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
> https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
> 
> 
> Should I look at different branch?

Now it is merged into the next tree you list above. See the commit:

author	HATAYAMA Daisuke <d.hatayama@xxxxxxxxxxxxxx>	2013-06-06 00:40:01 (GMT)
committer	Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx>	2013-06-06 05:50:03 (GMT)
commit	4be2c06c30e4c3994d86e0be24ff1af12d2c71d5 (patch)
tree	d7fb8c64c628600e8ba24481927f087fc11c2986
parent	99f80952861807e521ed30c22925f009f543a5ec (diff)

-- 
Thanks.
Zhang Yanfei
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