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 From : Sergey Lentsov                       2:4615/71.10   19 Apr 2002  21:20:16
 To : All
 Subject : URL: http://www.lwn.net/2002/0418/kernel.php3
 -------------------------------------------------------------------------------- 
 

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    [10]All in one big page
 
    See also: [11]last week's Kernel page.
 
 Kernel development
 
    The current development kernel is 2.5.8, which was [12]released on
    April 14. It contains a number of low-level memory and buffer
    management improvements by Andrew Morton, another set of IDE patches
    from Martin Dalecki (see below), Jens Axboe's IDE tagged command
    queueing code (discussed here [13]last week), a large set of ReiserFS
    fixes, a large PowerPC64 update, lots of USB updates, quite a few
    networking fixes, the usual set of VFS changes from Alexander Viro,
    and many other fixes and updates.
 
    Note that Linus [14]warns: "The TCQ stuff is definitely experimental,
    you should probably configure it out for now."
 
    No 2.5.9 prepatches have been issued as of this writing.
 
    The latest patch from Dave Jones is [15]2.5.8-dj1; it fixes a number
    of problems but Dave has not dug too deeply into the patch queue yet.
 
    Guillaume Boissiere's latest [16]2.5 status summary was released on
    April 17.
 
    The current stable kernel release is 2.4.18. The latest 2.4.19
    prepatch from Marcelo (produced when he wasn't busy [17]getting thrown
    out of the U.S.) is [18]2.4.19-pre7; it adds a very long list of new
    fixes and upgrades, but no major changes.
 
    There were no 2.4 prepatches from Alan Cox this week.
 
    The right way to clean up the IDE code. Working on the IDE subsystem
    seems to be a difficult and thankless task - especially if you are not
    always concerned about the troubles you create for some users. Martin
    Dalecki found himself on the firing line again after releasing his
    [19]IDE 36 patch, which included the following:
 
      Remove sector data byteswapping support. Byte-swapping the data is
      supported on the file-system level where applicable. Byte-swapped
      interfaces are supported on a lower level anyway. And finally it
      was used inconsistently
 
    There was only one problem: some people use and rely on that byte
    swapping feature. Filesystems can handle byte swapping in some
    situations - especially with their own metadata - but sometimes it is
    necessary to deal with a disk where everything is swapped. In
    particular, it seems that disks from TiVo systems require swapping to
    be readable on a Linux box.
 
    It can be dangerous to interfere with hackers trying to play with
    their TiVo systems.
 
    Despite the complaining, nobody is standing up for the old byte
    swapping implementation. It only worked in the (slow) programmed I/O
    mode, and could, in especially unlucky situations, lead to disk
    corruption. This feature clearly needed to be fixed in some way. But a
    number of people would have rather seen a replacement be provided
    before the old implementation was yanked.
 
    Linus, however, [20]does not agree:
 
      The fact is, many things are easier to fix afterwards. Particularly
      because that's the only time you'll find people motivated enough to
      bother about it. If you were to need to fix everything
      before-the-fact, nothing fundamental would ever get fixed, simply
      because the people who can fix one thing are not usually the same
      people who can fix another.
 
    In other words, a better byte swapping implementation simply is not
    going to happen until somebody really has to do it.
 
    This better implementation, in fact, will probably not live in the IDE
    subsystem, and, thus, will probably not be done by Martin. The
    consensus seems to be that full byte swapping belongs in the loopback
    driver, where it can be slotted in when needed. No implementations
    have been posted, but it should not be that difficult for somebody to
    do.
 
    Where are the VM updates for 2.5?. Mike Fedyk [21]asked:
 
      Why haven't any of the -aa VM updates gone into 2.5? Especially
      after Andrew Morton has split it up this is surprising...
 
    Given the amount of VM work that happened just before the 2.5 fork,
    and given that Andrea's changes are said to improve performance and
    stability in a number of ways, it is interesting that VM development
    seems to have stopped in 2.5. Appearances can be deceiving, though:
    Andrew Morton's buffer management and I/O work certainly affects
    memory management. Rik van Riel, William Lee Irwin, and others have
    gotten VM-related patches into 2.5. Nonetheless, not much VM work is
    happening in 2.5. Andrew Morton [22]posted a few reasons why that
    might be, including:
 
      * Not much work is happening with 2.5 VM. The VM hackers are mostly
        still working with 2.4; the job there is incomplete, and it
        provides a more stable platform for VM developments (such as Rik
        van Riel's reverse mapping (rmap) code).
      * Other work, such as the buffer management changes, tends to
        conflict with extensive VM changes.
      * The general direction of VM development in 2.5 is still unknown.
        For example, no decision has been made on the inclusion of rmap in
        2.5. There isn't even a 2.5 rmap patch yet.
 
    Andrea Arcangeli, meanwhile, [23]would like to see his changes in 2.5:
 
      The fact is that in all the feedback I got so far I didn't seen
      anything that surpasses my vm-33 updates, certainly not mainline
      without them, certainly not the rmap patch either, and this is why
      I'm assuming vm-33 is the right thing to merge at this point in
      time into both 2.4 and 2.5.
 
    Andrea also states that he is done with 2.4 work unless a problem
    comes up.
 
    Linus has not chimed in with his view of where the VM work should go,
    so there is really no way of knowing what might get merged when. This
    could be cause for a bit of concern. The 2.3/2.4 experience
    demonstrated, clearly, that VM changes should not be left to the end
    of a development cycle. VM work can take a very long time to
    stabilize, so any big changes should be in place well before one even
    begins to think about stable releases.
 
    The Linux Trace Toolkit is now [24]available for the 2.5 kernel. LTT
    allows for detailed, dynamic tracing of the kernel; it can be
    invaluable for tracking down obscure, timing-related problems. LTT is
    shipped by some vendors (especially embedded Linux companies), but is
    not part of the standard kernel. Karim Yaghmour, author of LTT, would
    like to change that:
 
      In the past, many have shown interest and support for LTT's
      inclusion in the standard kernel tree. I won't fill this mail with
      names, but Alan Cox, for instance, is one of them
 
    LTT is a useful tool for looking inside the operation of the kernel.
    There is no word, of course, on whether it will eventually be merged
    into the mainline kernel; it remains, however, just one patch away.
 
    Other patches and updates released this week include:
 
    Kernel trees:
      * Shawn Starr: [25]2.4.19-pre6-rmap-12i-xfs-shawn11. a combination
        of 2.4.19-pre6, the rmap patch, and XFS.
      * Paul P Komkoff Jr: [26]2.4.19-pre5-ac3-s45. Includes some patches
        that [27]maybe should not be there.
      * J.A. Magallon: [28]2.4.19-pre7-jam1.
 
    Core kernel code:
      * Zlatko Calusic: [29]port of sard I/O accounting patch to
        2.5.8-pre3.
      * Rik van Riel: [30]helper macros for VM code.
      * Robert Love: [31]CPU affinity system calls for 2.4.
      * Daniel Phillips: [32]mm.h header splitup allowing some low-level
        macros to be changed to inline functions. "I didn't fix any of the
        mistakes that were exposed by compiling with the inlines, e.g.,
        passing ulong to virt_to_phys instead of (void *). It's arguably
        better to observe firsthand the kind of cruft that the inlines are
        able to expose."
      * Randy Dunlap: [33]bounce and swap stats for 2.5.
      * William Lee Irwin: [34]per-zone pte_chain freelists.
      * Eric W. Biederman, x86 boot enhancements: [35]1, [36]2, [37]3,
        [38]4, [39]5, [40]6, [41]7, [42]8, [43]9, [44]10, and [45]11.
 
    Development tools:
      * Yumiko Sugita, [46]Linux Kernel State Tracer 1.0.
 
    Device drivers
      * Martin Dalecki: IDE subsystem cleanup patches: [47]32, [48]33,
        [49]34, [50]35, and [51]36.
      * Jens Axboe: [52]IDE tagged command queueing #4.
      * Jeff Merkey: [53]Dolphin PCI-SCI drivers for 2.5.7.
      * Richard Gooch: [54]devfs v210 (for 2.5.8) and [55]devfs v199.13
        (for 2.4.19-pre7).
      * Rob Radez: [56]watchdog driver updates.
      * Greg Kroah-Hartman: [57]Lineo's USB device implementation
        (discussed [58]last week). Note that this support will likely be
        renamed "USB client," and Linus is [59]unimpressed by the patch.
      * Justin Gibbs: [60]AIC7xxx driver 6.2.6 for 2.4.
      * Michael Clark: [61]SAFTE SCSI enclosure monitor.
 
    Kernel building:
      * Keith Owens: [62]updates to kbuild 2.5.
 
    Miscellaneous:
      * [63]Kernel Traffic for April 15 is available.
      * Jari Ruusu: [64]Loop-AES file/swap crypto package v1.6b.
 
    Networking:
      * Dmitry Kasatkin: [65]Affix 0_99.
 
    Ports:
      * James Bottomley: [66]NCR Voyager support, now with SMP support.
 
    Section Editor: [67]Jonathan Corbet
    April 18, 2002
 
                                Sponsored Link
 
    [68]Your Text Ad Here
 
    Purchase your own text ad with our self-serve advertising system.
 
    For other kernel news, see:
      * [69]Kernel traffic
      * [70]Kernel Newsflash
      * [71]Kernel Trap
      * [72]Linux 2.5.x Porting help
      * [73]2.5 Status
    
    Other resources:
      * [74]Kernel Source Reference
      * [75]L-K mailing list FAQ
      * [76]Linux-MM
      * [77]Linux Scalability Effort
      * [78]Kernel Newbies
      * [79]Linux Device Drivers
    
    
 
                                                   [80]Next: Distributions
 
    [81]Eklektix, Inc. Linux powered! Copyright Л 2002 [82]Eklektix, Inc.,
    all rights reserved
    Linux (R) is a registered trademark of Linus Torvalds
 
 References
 
    1. http://lwn.net/
    2. http://lwn.net/2002/0418/
    3. http://lwn.net/2002/0418/security.php3
    4. http://lwn.net/2002/0418/dists.php3
    5. http://lwn.net/2002/0418/devel.php3
    6. http://lwn.net/2002/0418/commerce.php3
    7. http://lwn.net/2002/0418/press.php3
    8. http://lwn.net/2002/0418/announce.php3
    9. http://lwn.net/2002/0418/letters.php3
   10. http://lwn.net/2002/0418/bigpage.php3
   11. http://lwn.net/2002/0411/kernel.php3
   12. http://lwn.net/2002/0418/a/2.5.8.php3
   13. http://lwn.net/2002/0411/kernel.php3
   14. http://lwn.net/2002/0418/a/lt-tcq.php3
   15. http://lwn.net/2002/0418/a/2.5.8-dj1.php3
   16. http://lwn.net/2002/0418/a/2.5-status.php3
   17. http://www.vnunet.com/News/1130948
   18. http://lwn.net/2002/0418/a/2.4.19-pre7.php3
   19. http://lwn.net/2002/0418/a/ide-36.php3
   20. http://lwn.net/2002/0418/a/lt-breakage.php3
   21. http://lwn.net/2002/0418/a/why-not-aa.php3
   22. http://lwn.net/2002/0418/a/am-vm.php3
   23. http://lwn.net/2002/0418/a/aa-vm.php3
   24. http://lwn.net/2002/0418/a/ltt.php3
   25. http://lwn.net/2002/0418/a/2.4.19-pre6-rmap-12i-xfs-shawn11.php3
   26. http://lwn.net/2002/0418/a/2.4.19-pre5-ac3-s45.php3
   27. http://lwn.net/2002/0418/a/unannounced-patches.php3
   28. http://lwn.net/2002/0418/a/2.4.19-pre7-jam1.php3
   29. http://lwn.net/2002/0418/a/sard.php3
   30. http://lwn.net/2002/0418/a/vm-macros.php3
   31. http://lwn.net/2002/0418/a/affinity.php3
   32. http://lwn.net/2002/0418/a/header-splitup.php3
   33. http://lwn.net/2002/0418/a/bounce-stats.php3
   34. http://lwn.net/2002/0418/a/pte-chain.php3
   35. http://lwn.net/2002/0418/a/boot-1.php3
   36. http://lwn.net/2002/0418/a/boot-2.php3
   37. http://lwn.net/2002/0418/a/boot-3.php3
   38. http://lwn.net/2002/0418/a/boot-4.php3
   39. http://lwn.net/2002/0418/a/boot-5.php3
   40. http://lwn.net/2002/0418/a/boot-6.php3
   41. http://lwn.net/2002/0418/a/boot-7.php3
   42. http://lwn.net/2002/0418/a/boot-8.php3
   43. http://lwn.net/2002/0418/a/boot-9.php3
   44. http://lwn.net/2002/0418/a/boot-10.php3
   45. http://lwn.net/2002/0418/a/boot-11.php3
   46. http://lwn.net/2002/0418/a/lkst.php3
   47. http://lwn.net/2002/0418/a/ide-32.php3
   48. http://lwn.net/2002/0418/a/ide-33.php3
   49. http://lwn.net/2002/0418/a/ide-34.php3
   50. http://lwn.net/2002/0418/a/ide-35.php3
   51. http://lwn.net/2002/0418/a/ide-36.php3
   52. http://lwn.net/2002/0418/a/tcq.php3
   53. http://lwn.net/2002/0418/a/dolphin.php3
   54. http://lwn.net/2002/0418/a/devfs-v210.php3
   55. http://lwn.net/2002/0418/a/devfs-v199.13.php3
   56. http://lwn.net/2002/0418/a/watchdog.php3
   57. http://lwn.net/2002/0418/a/usb-device.php3
   58. http://lwn.net/2002/0411/kernel.php3
   59. http://lwn.net/2002/0418/a/lt-usb-device.php3
   60. http://lwn.net/2002/0418/a/aic7xxx.php3
   61. http://lwn.net/2002/0418/a/safte.php3
   62. http://lwn.net/2002/0418/a/kbuild.php3
   63. http://kt.zork.net/kernel-traffic/kt20020415_162.html
   64. http://lwn.net/2002/0418/a/loop-aes.php3
   65. http://lwn.net/2002/0418/a/affix.php3
   66. http://lwn.net/2002/0418/a/voyager.php3
   67. mailto:lwn@lwn.net
   68.
 http://oasis.lwn.net/oasisc.php?s=5&c=5&cb=618229987&url=http%3A%2F%2Flwn.net%2F
 corp%2Fadvertise%2Ftext%2F
   69. http://kt.zork.net/
   70. http://www.atnf.csiro.au/~rgooch/linux/docs/kernel-newsflash.html
   71. http://www.kerneltrap.com/
   72. http://www.osdl.org/archive/rddunlap/linux-port-25x.html
   73. http://kernelnewbies.org/status/
   74. http://lksr.org/
   75. http://www.tux.org/lkml/
   76. http://www.linux.eu.org/Linux-MM/
   77. http://lse.sourceforge.net/
   78. http://www.kernelnewbies.org/
   79. http://www.xml.com/ldd/chapter/book/index.html
   80. http://lwn.net/2002/0418/dists.php3
   81. http://www.eklektix.com/
   82. http://www.eklektix.com/
 
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