When looking at a performance problem on PowerPC, I noticed some awful code
generation:
c00000000051fc98: 3b 60 00 01 li r27,1
...
c00000000051fca0: 3b 80 00 00 li r28,0
...
c00000000051fcdc: 93 61 00 70 stw r27,112(r1)
c00000000051fce0: 93 81 00 74 stw r28,116(r1)
c00000000051fce4: 81 21 00 70 lwz r9,112(r1)
c00000000051fce8: 80 01 00 74 lwz r0,116(r1)
c00000000051fcec: 7d 29 07 b4 extsw r9,r9
c00000000051fcf0: 7c 00 07 b4 extsw r0,r0
c00000000051fcf4: 7c 20 04 ac lwsync
c00000000051fcf8: 7d 60 f8 28 lwarx r11,0,r31
c00000000051fcfc: 7c 0b 48 00 cmpw r11,r9
c00000000051fd00: 40 c2 00 10 bne- c00000000051fd10
c00000000051fd04: 7c 00 f9 2d stwcx. r0,0,r31
c00000000051fd08: 40 c2 ff f0 bne+ c00000000051fcf8
c00000000051fd0c: 4c 00 01 2c isync
We create two constants, write them out to the stack, read them straight back
in and sign extend them. What a mess.
It turns out this bad code is a result of us defining atomic_t as a
volatile int.
We removed the volatile attribute from the powerpc atomic_t definition years
ago, but commit ea43546750 (atomic_t: unify all
arch definitions) added it back in.
To dig up an old quote from Linus:
> The fact is, volatile on data structures is a bug. It's a wart in the C
> language. It shouldn't be used.
>
> Volatile accesses in *code* can be ok, and if we have "atomic_read()"
> expand to a "*(volatile int *)&(x)->value", then I'd be ok with that.
>
> But marking data structures volatile just makes the compiler screw up
> totally, and makes code for initialization sequences etc much worse.
And screw up it does :)
With the volatile removed, we see much more reasonable code generation:
c00000000051f5b8: 3b 60 00 01 li r27,1
...
c00000000051f5c0: 3b 80 00 00 li r28,0
...
c00000000051fc7c: 7c 20 04 ac lwsync
c00000000051fc80: 7c 00 f8 28 lwarx r0,0,r31
c00000000051fc84: 7c 00 d8 00 cmpw r0,r27
c00000000051fc88: 40 c2 00 10 bne- c00000000051fc98
c00000000051fc8c: 7f 80 f9 2d stwcx. r28,0,r31
c00000000051fc90: 40 c2 ff f0 bne+ c00000000051fc80
c00000000051fc94: 4c 00 01 2c isync
Six instructions less.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Follow-up to "block: enable by default support for large devices
and files on 32-bit archs".
Rename CONFIG_LBD to CONFIG_LBDAF to:
- allow update of existing [def]configs for "default y" change
- reflect that it is used also for large files support nowadays
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
With the last used of non-strict names gone from the
exported header files, we can remove the old libc5
compatibility cruft from our headers and only export
strict types.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The typedefs for __u64 and __s64 where fixed to be available for other
compiler on May 2 2008 by H. Peter Anvin (in commit edfa5cfa3d)
Acked-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Detlef Riekenberg <wine.dev@web.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The atomic_t type cannot currently be used in some header files because it
would create an include loop with asm/atomic.h. Move the type definition
to linux/types.h to break the loop.
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We have two seperate config entries for large devices/files. One
is CONFIG_LBD that guards just the devices, the other is CONFIG_LSF
that handles large files. This doesn't make a lot of sense, you typically
want both or none. So get rid of CONFIG_LSF and change CONFIG_LBD wording
to indicate that it covers both.
Acked-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
There's no good reason why a resource_size_t shouldn't just be a
physical address, so simply redefine it in terms of phys_addr_t.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Add a kernel-wide "phys_addr_t" which is guaranteed to be able to hold
any physical address. By default it equals the word size of the
architecture, but a 32-bit architecture can set ARCH_PHYS_ADDR_T_64BIT
if it needs a 64-bit phys_addr_t.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
<linux/types.h> can't be used together with <sys/ustat.h> because they
both define struct ustat:
$ cat test.c
#include <sys/ustat.h>
#include <linux/types.h>
$ gcc -c test.c
In file included from test.c:2:
/usr/include/linux/types.h:165: error: redefinition of 'struct ustat'
has been reported a while ago to debian, but seems to have been
lost in cat fighting: http://bugs.debian.org/429064
Signed-off-by: maximilian attems <max@stro.at>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
All of the asm-*/types.h headers have been updated to no longer check
__STRICT_ANSI__ for the 64bit types, so this brings linux/types.h in line.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Jan Engelhardt <jengelh@computergmbh.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Use of ptrdiff_t in places like
- if (!access_ok(VERIFY_WRITE, u_tmp->rx_buf, u_tmp->len))
+ if (!access_ok(VERIFY_WRITE, (u8 __user *)
+ (ptrdiff_t) u_tmp->rx_buf,
+ u_tmp->len))
is wrong; for one thing, it's a bad C (it's what uintptr_t is for; in general
we are not even promised that ptrdiff_t is large enough to hold a pointer,
just enough to hold a difference between two pointers within the same object).
For another, it confuses the fsck out of sparse.
Use unsigned long or uintptr_t instead. There are several places misusing
ptrdiff_t; fixed.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
define first set of BIT* macros
- move BITOP_MASK and BITOP_WORD from asm-generic/bitops/atomic.h to
include/linux/bitops.h and rename it to BIT_MASK and BIT_WORD
- move BITS_TO_LONGS and BITS_PER_BYTE to bitops.h too and allow easily
define another BITS_TO_something (e.g. in event.c) by BITS_TO_TYPE macro
Remaining (and common) BIT macro will be defined after all occurences and
conflicts will be sorted out in the patches.
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
CONFIG_LBD and CONFIG_LSF are spread into asm/types.h for no particularly
good reason.
Centralising the definition in linux/types.h means that arch maintainers
don't need to bother adding it, as well as fixing the problem with
x86-64 users being asked to make a decision that has absolutely no
effect.
The H8/300 porters seem particularly confused since I'm not aware of any
microcontrollers that need to support 2TB filesystems.
Signed-off-by: Matthew Wilcox <matthew@wil.cx>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
New types - for 16bit checksums and "unfolded" 32bit variant.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch defines:
* a generic boolean-type, named 'bool'
* aliases to 0 and 1, named 'false' and 'true'
Removing colliding definitions of 'bool', 'false' and 'true'.
Signed-off-by: Richard Knutsson <ricknu-0@student.ltu.se>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Introduce the Kconfig entry and actually switch to a 64bit value, if
wanted, for resource_size_t.
Based on a patch series originally from Vivek Goyal <vgoyal@in.ibm.com>
Cc: Vivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
But do not change it from what it currently is (unsigned long)
Based on a patch series originally from Vivek Goyal <vgoyal@in.ibm.com>
Cc: Vivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Add blkcnt_t as the type of inode.i_blocks. This enables you to make the size
of blkcnt_t either 4 bytes or 8 bytes on 32 bits architecture with CONFIG_LSF.
- CONFIG_LSF
Add new configuration parameter.
- blkcnt_t
On h8300, i386, mips, powerpc, s390 and sh that define sector_t,
blkcnt_t is defined as u64 if CONFIG_LSF is enabled; otherwise it is
defined as unsigned long.
On other architectures, it is defined as unsigned long.
- inode.i_blocks
Change the type from sector_t to blkcnt_t.
Signed-off-by: Takashi Sato <sho@tnes.nec.co.jp>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This can make the intent behind some arithmetic expressions clearer.
Signed-off-by: Bryan O'Sullivan <bos@pathscale.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Beginning of gfp_t annotations:
- -Wbitwise added to CHECKFLAGS
- old __bitwise renamed to __bitwise__
- __bitwise defined to either __bitwise__ or nothing, depending on
__CHECK_ENDIAN__ being defined
- gfp_t switched from __nocast to __bitwise__
- force cast to gfp_t added to __GFP_... constants
- new helper - gfp_zone(); extracts zone bits out of gfp_t value and casts
the result to int
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
- added typedef unsigned int __nocast gfp_t;
- replaced __nocast uses for gfp flags with gfp_t - it gives exactly
the same warnings as far as sparse is concerned, doesn't change
generated code (from gcc point of view we replaced unsigned int with
typedef) and documents what's going on far better.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
As proposed by Andi Kleen, this is required esp. for x86_64 architecture,
where 64bit code needs 8byte aligned 64bit data types, but 32bit userspace
apps will only align to 4bytes.
Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
