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
..
boot	microblaze: Remove *.dtb files in make clean	2015-02-10 16:24:39 +01:00
configs	KEYS: CONFIG_KEYS_DEBUG_PROC_KEYS is no longer an option	2016-02-10 10:13:27 +00:00
include	Merge branch 'hash' of git://ftp.sciencehorizons.net/linux	2016-05-28 16:15:25 -07:00
kernel	microblaze: Wire up userfaultfd, membarrier, mlock2 syscalls	2016-05-16 09:18:01 +02:00
lib	microblaze: Change libgcc-style functions from lib-y to obj-y	2014-07-18 14:26:09 +02:00
mm	mm/fault, arch: Use pagefault_disable() to check for disabled pagefaults in the handler	2015-05-19 08:39:15 +02:00
oprofile
pci	microblaze: pci: export isa_io_base to fix link errors	2016-05-16 09:18:10 +02:00
Kconfig	Merge branch 'hash' of git://ftp.sciencehorizons.net/linux	2016-05-28 16:15:25 -07:00
Kconfig.debug	microblaze: remove obsolete DEBUG_BOOTMEM	2011-01-10 09:29:51 +01:00
Kconfig.platform	microblaze: Remove platform folder	2014-04-07 13:45:21 +02:00
Makefile	microblaze: Remove platform folder	2014-04-07 13:45:21 +02:00