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Linus Torvalds 7e0fb73c52 Merge branch 'hash' of git://ftp.sciencehorizons.net/linux 
Pull string hash improvements from George Spelvin:
 "This series does several related things:

   - Makes the dcache hash (fs/namei.c) useful for general kernel use.

     (Thanks to Bruce for noticing the zero-length corner case)

   - Converts the string hashes in <linux/sunrpc/svcauth.h> to use the
     above.

   - Avoids 64-bit multiplies in hash_64() on 32-bit platforms.  Two
     32-bit multiplies will do well enough.

   - Rids the world of the bad hash multipliers in hash_32.

     This finishes the job started in commit 689de1d6ca ("Minimal
     fix-up of bad hashing behavior of hash_64()")

     The vast majority of Linux architectures have hardware support for
     32x32-bit multiply and so derive no benefit from "simplified"
     multipliers.

     The few processors that do not (68000, h8/300 and some models of
     Microblaze) have arch-specific implementations added.  Those
     patches are last in the series.

   - Overhauls the dcache hash mixing.

     The patch in commit 0fed3ac866 ("namei: Improve hash mixing if
     CONFIG_DCACHE_WORD_ACCESS") was an off-the-cuff suggestion.
     Replaced with a much more careful design that's simultaneously
     faster and better.  (My own invention, as there was noting suitable
     in the literature I could find.  Comments welcome!)

   - Modify the hash_name() loop to skip the initial HASH_MIX().  This
     would let us salt the hash if we ever wanted to.

   - Sort out partial_name_hash().

     The hash function is declared as using a long state, even though
     it's truncated to 32 bits at the end and the extra internal state
     contributes nothing to the result.  And some callers do odd things:

      - fs/hfs/string.c only allocates 32 bits of state
      - fs/hfsplus/unicode.c uses it to hash 16-bit unicode symbols not bytes

   - Modify bytemask_from_count to handle inputs of 1..sizeof(long)
     rather than 0..sizeof(long)-1.  This would simplify users other
     than full_name_hash"

  Special thanks to Bruce Fields for testing and finding bugs in v1.  (I
  learned some humbling lessons about "obviously correct" code.)

  On the arch-specific front, the m68k assembly has been tested in a
  standalone test harness, I've been in contact with the Microblaze
  maintainers who mostly don't care, as the hardware multiplier is never
  omitted in real-world applications, and I haven't heard anything from
  the H8/300 world"

* 'hash' of git://ftp.sciencehorizons.net/linux:
  h8300: Add <asm/hash.h>
  microblaze: Add <asm/hash.h>
  m68k: Add <asm/hash.h>
  <linux/hash.h>: Add support for architecture-specific functions
  fs/namei.c: Improve dcache hash function
  Eliminate bad hash multipliers from hash_32() and  hash_64()
  Change hash_64() return value to 32 bits
  <linux/sunrpc/svcauth.h>: Define hash_str() in terms of hashlen_string()
  fs/namei.c: Add hashlen_string() function
  Pull out string hash to <linux/stringhash.h>
 		2016-05-28 16:15:25 -07:00
..
common [media] tpg: Export the tpg code from vivid as a module 2016-04-20 16:14:39 -03:00
dvb-core [media] media/dvb-core: forward media_create_pad_links() return value 2016-05-07 10:56:55 -03:00
dvb-frontends Merge branch 'i2c/for-4.7' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux 2016-05-19 17:48:12 -07:00
firewire [media] dvb: modify core to implement interfaces/entities at MC new gen 2016-01-11 12:18:52 -02:00
i2c remove lots of IS_ERR_VALUE abuses 2016-05-27 15:26:11 -07:00
mmc [media] siano: register media controller earlier 2015-02-26 09:10:39 -03:00
pci [media] smipcie: add RC map into card configuration options 2016-05-07 10:27:18 -03:00
platform remove lots of IS_ERR_VALUE abuses 2016-05-27 15:26:11 -07:00
radio [media] tea575x: convert to library 2016-02-10 09:34:28 -02:00
rc [media] drivers/media/rc: postpone kfree(rc_dev) 2016-05-07 11:21:04 -03:00
tuners [media] em28xx: add support for PLEX PX-BCUD (ISDB-S) 2016-05-06 23:51:47 -03:00
usb Merge branch 'hash' of git://ftp.sciencehorizons.net/linux 2016-05-28 16:15:25 -07:00
v4l2-core media updates for v4.7-rc1 2016-05-18 17:03:51 -07:00
Kconfig [media] Kconfig: Re-enable Media controller support for DVB 2016-01-11 12:18:40 -02:00
Makefile [media] bq/c-qcam, w9966, pms: move to staging in preparation for removal 2014-12-16 23:21:44 -02:00
media-device.c Linux 4.6-rc7 2016-05-09 12:21:49 -03:00
media-devnode.c [media] drivers/media/media-devnode: clear private_data before put_device() 2016-05-07 11:43:53 -03:00
media-entity.c [media] media: change pipeline validation return error 2016-04-29 08:07:17 -03:00