Re: [LTP] [PATCH v2] mmap/munmap /dev/zero

[Mike F. <va...@ge...>]

On Tuesday, October 12, 2010 22:02:28 ca...@re... wrote:
> Add a new test to mmap/munmap /dev/zero. A common way of malloc()/free()
> anonymous memory on Solaris. Anyway, mmap() of /dev/zero results in
> calling map_zero() which on RHEL5 maps the ZERO_PAGE in every pte within
> that virtual address range. Since a application is also multi-threaded the
> subsequent munmap() of /dev/zero results is TLB shootdowns to all other
> CPUs.  When this happens thousands or millions of times the application
> performance is terrible. The mapping ZERO_PAGE in every pte within that
> virtual address range was an optimization to make the subsequent pagefault
> times faster on RHEL5 that has been removed/changed upstream.

you need to fix your mailer and/or use `git send-email`.  changelogs must be 
line wrapped to the standard e-mail length (or even a few chars shorter).

further, your e-mail lacks the marker "---" which tells git where the 
changelog ends.  `git send-email` takes care of this for you too.

patch changelogs (i.e. what changed in v2, v3, ....) should be below the "---" 
marker or at the end of the changelog (not the start).  personally, i prefer 
the "---" system.
-mike