int

posix_madvise (void *addr, size_t len, int advice)

{

  /* We have one problem: the kernel's MADV_DONTNEED does not

     correspond to POSIX's POSIX_MADV_DONTNEED.  The former simply

     discards changes made to the memory without writing it back to

     disk, if this would be necessary.  The POSIX behavior does not

     allow this.  There is no functionality mapping the POSIX behavior

     so far so we ignore that advice for now.  */

  if (advice == POSIX_MADV_DONTNEED)

    return 0;



  INTERNAL_SYSCALL_DECL (err);

  int result = INTERNAL_SYSCALL (madvise, err, 3, addr, len, advice);

  return INTERNAL_SYSCALL_ERRNO (result, err);

}

Chris Worley wrote:
..
> The OS should not assume a dumb algorithm on the part of the drive.
..

Welcome to the Real World.

Gidday!

You are receiving this mail because:
a) I'm the maintainer of the man-pages project
(http://www.kernel.org/doc/man-pages/);
b) you've (directly or indirectly) contributed to the project during
my tenure as maintainer; and
c) because of (b), the topic of this mail may be of interest to you.

During the last few years I've been working on a book on Linux and
Unix system programming--in other words, a book that covers many of
the same areas as the man-pages project. This book is finally nearing
completion. It will be published in the first half of 2010 by No
Starch press (http://www.nostarch.com/.)

The book is intended to be comprehensive: it has 64 chapters, 116
diagrams, 85 tables, around 250 program listings, and it will run to
about 1500 pages (precise number depends on typesetting). I'm running
a blog about the book and its ongoing progress towards publication.
The blog is at http://blog.man7.org/. (The surrounding website at that
domain has yet to be built out.) In particular, there are two posts
that give an overview of the book and its contents:
http://blog.man7.org/2009/07/whats-book-about.html
http://blog.man7.org/2009/07/64-chapters.html
and over the next couple of months I'm posting the detailed table of
contents of each chapter. (In the next few weeks I expect to start
getting typeset chapters from the publisher, and I hope soon after
that to be able to post one or two for public viewing.)

As with any book, getting the word out matters a great deal. Please
feel free to post comments at blog.man7.org, blog about my blog on
your blog, or simply forward this mail to people who you think may be
interested in the book. And of course, let me know if you have
questions about the book.

You'll notice that the blog still doesn't mention a title for the
book. That's because the publisher and I still haven't worked out
precisely what it will be. (We're tossing up between a few ideas.) The
book title will be the subject of a future post. If, after learning
more from the blog, you have title ideas, please feel free to
suggestions to me.

Finally, in case you are concerned that you've been added to some list
that will result in you receiving lots of mail from me, don't worry.
This is a near-one-time announcement. Most of you will get exactly one
more mail from me (unless I know you via some other channel than
man-pages), when the book is actually on bookshelves in 2010.

Best regards,

Michael

PS Apologies if you received more than one copy of this mail. Some of
you contributed to man-pages under more than one email address, and
I'm not sure which address is current, or is your primary address.

--
Watch my book progress to publication! http://blog.man7.org/

KOSAKI Motohiro (1):

      mm: revert "oom: move oom_adj value"

On another security related note, David Wagner drew attention to a security paper from this year’s USENIX playing up the impact of making various files world readable in the task directories under /proc. In one case, they are able to use the ESP and EIP information from a task stat file to recover information about another user’s keystrokes, which is potentially a security issue. This said, there have long been patches available (such as grsecurity) that hide various process statistics from other users, and it would be relatively trivial to adapt one of these for mainstream consumption. Co-incidentally, Kosaki Motohiro posted a patch (from Tatsuhiro Aoshima) adding more statistics to the aforementioned state file, for user time and system time consumed by the task. One awaits the next alarmist paper.