Re: [PATCH 4/4] mm: numa: Slow PTE scan rate if migration failures occur

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Wed, Mar 18, 2015 at 9:08 AM, Linus Torvalds
<torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
>
> So why am I wrong? Why is testing for dirty not the same as testing
> for writable?
>
> I can see a few cases:
>
>  - your load has lots of writable (but not written-to) shared memory

Hmm. I tried to look at the xfsprog sources, and I don't see any
MAP_SHARED activity.  It looks like it's just using pread64/pwrite64,
and the only MAP_SHARED is for the xfsio mmap test thing, not for
xfsrepair.

So I don't see any shared mappings, but I don't know the code-base.

>  - something completely different that I am entirely missing

So I think there's something I'm missing. For non-shared mappings, I
still have the idea that pte_dirty should be the same as pte_write.
And yet, your testing of 3.19 shows that it's a big difference.
There's clearly something I'm completely missing.

                          Linus

_______________________________________________
xfs mailing list
xfs@xxxxxxxxxxx
http://oss.sgi.com/mailman/listinfo/xfs




[Index of Archives]     [Linux XFS Devel]     [Linux Filesystem Development]     [Filesystem Testing]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux