Skip to content

K
Kernel

openeuler / Kernel
1 年多 前同步成功

通知 8
Star 0
Fork 0
K
Kernel
切换分支/标签
  1. 09 2月, 2008 2 次提交
    • H
      avoid overflows in kernel/time.c · bdc80787
      由 H. Peter Anvin 提交于 
      When the conversion factor between jiffies and milli- or microseconds is
not a single multiply or divide, as for the case of HZ == 300, we currently
do a multiply followed by a divide.  The intervening result, however, is
subject to overflows, especially since the fraction is not simplified (for
HZ == 300, we multiply by 300 and divide by 1000).

This is exposed to the user when passing a large timeout to poll(), for
example.

This patch replaces the multiply-divide with a reciprocal multiplication on
32-bit platforms.  When the input is an unsigned long, there is no portable
way to do this on 64-bit platforms there is no portable way to do this
since it requires a 128-bit intermediate result (which gcc does support on
64-bit platforms but may generate libgcc calls, e.g.  on 64-bit s390), but
since the output is a 32-bit integer in the cases affected, just simplify
the multiply-divide (*3/10 instead of *300/1000).

The reciprocal multiply used can have off-by-one errors in the upper half
of the valid output range.  This could be avoided at the expense of having
to deal with a potential 65-bit intermediate result.  Since the intent is
to avoid overflow problems and most of the other time conversions are only
semiexact, the off-by-one errors were considered an acceptable tradeoff.

At Ralf Baechle's suggestion, this version uses a Perl script to compute
the necessary constants.  We already have dependencies on Perl for kernel
compiles.  This does, however, require the Perl module Math::BigInt, which
is included in the standard Perl distribution starting with version 5.8.0.
In order to support older versions of Perl, include a table of canned
constants in the script itself, and structure the script so that
Math::BigInt isn't required if pulling values from said table.

Running the script requires that the HZ value is available from the
Makefile.  Thus, this patch also adds the Kconfig variable CONFIG_HZ to the
architectures which didn't already have it (alpha, cris, frv, h8300, m32r,
m68k, m68knommu, sparc, v850, and xtensa.) It does *not* touch the sh or
sh64 architectures, since Paul Mundt has dealt with those separately in the
sh tree.
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
Cc: Ralf Baechle <ralf@linux-mips.org>,
Cc: Sam Ravnborg <sam@ravnborg.org>,
Cc: Paul Mundt <lethal@linux-sh.org>,
Cc: Richard Henderson <rth@twiddle.net>,
Cc: Michael Starvik <starvik@axis.com>,
Cc: David Howells <dhowells@redhat.com>,
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>,
Cc: Hirokazu Takata <takata@linux-m32r.org>,
Cc: Geert Uytterhoeven <geert@linux-m68k.org>,
Cc: Roman Zippel <zippel@linux-m68k.org>,
Cc: William L. Irwin <sparclinux@vger.kernel.org>,
Cc: Chris Zankel <chris@zankel.net>,
Cc: H. Peter Anvin <hpa@zytor.com>,
Cc: Jan Engelhardt <jengelh@computergmbh.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      bdc80787
    • D
      aout: mark arches that support A.OUT format · b0b933c0
      由 David Howells 提交于 
      Mark arches that support A.OUT format by including the following in their
master Kconfig files:

	config ARCH_SUPPORTS_AOUT
		def_bool y

This should also be set if the arch provides compatibility A.OUT support for
an older arch, for instance x86_64 for i386 or sparc64 for sparc.

I've guessed at which arches don't, based on comments in the code, however I'm
sure that some of the ones I've marked as 'yes' actually should be 'no'.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      b0b933c0
  3. 03 2月, 2008 3 次提交
    • A
      remove Documentation/smp.txt · 03502faa
      由 Adrian Bunk 提交于 
      After seeing the filename I'd have expected something about the
implementation of SMP in the Linux kernel - not some notes on kernel
configuration and building trivialities noone would search at this
place.
Signed-off-by: NAdrian Bunk <bunk@kernel.org>
Acked-by: NAlan Cox <alan@redhat.com>
      03502faa
    • M
      Move Kconfig.instrumentation to arch/Kconfig and init/Kconfig · 125e5645
      由 Mathieu Desnoyers 提交于 
      Move the instrumentation Kconfig to

arch/Kconfig for architecture dependent options
  - oprofile
  - kprobes

and

init/Kconfig for architecture independent options
  - profiling
  - markers

Remove the "Instrumentation Support" menu. Everything moves to "General setup".
Delete the kernel/Kconfig.instrumentation file.
Signed-off-by: NMathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>
      125e5645
    • M
      Add HAVE_OPROFILE · 42d4b839
      由 Mathieu Desnoyers 提交于 
      Linus:
On the per-architecture side, I do think it would be better to *not* have
internal architecture knowledge in a generic file, and as such a line like

        depends on X86_32 || IA64 || PPC || S390 || SPARC64 || X86_64 || AVR32

really shouldn't exist in a file like kernel/Kconfig.instrumentation.

It would be much better to do

        depends on ARCH_SUPPORTS_KPROBES

in that generic file, and then architectures that do support it would just
have a

        bool ARCH_SUPPORTS_KPROBES
                default y

in *their* architecture files. That would seem to be much more logical,
and is readable both for arch maintainers *and* for people who have no
clue - and don't care - about which architecture is supposed to support
which interface...

Changelog:

Actually, I know I gave this as the magic incantation, but now that I see
it, I realize that I should have told you to just use

        config ARCH_SUPPORTS_KPROBES
                def_bool y

instead, which is a bit denser.

We seem to use both kinds of syntax for these things, but this is really
what "def_bool" is there for...

Changelog :

- Moving to HAVE_*.
- Add AVR32 oprofile.
Signed-off-by: NMathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>
      42d4b839
  5. 20 10月, 2007 1 次提交
  7. 17 10月, 2007 1 次提交
  9. 20 7月, 2007 1 次提交
  11. 18 7月, 2007 2 次提交
  13. 12 7月, 2007 1 次提交
  15. 29 5月, 2007 1 次提交
  17. 12 2月, 2007 1 次提交
    • C
      [PATCH] Set CONFIG_ZONE_DMA for arches with GENERIC_ISA_DMA · 5ac6da66
      由 Christoph Lameter 提交于 
      As Andi pointed out: CONFIG_GENERIC_ISA_DMA only disables the ISA DMA
channel management.  Other functionality may still expect GFP_DMA to
provide memory below 16M.  So we need to make sure that CONFIG_ZONE_DMA is
set independent of CONFIG_GENERIC_ISA_DMA.  Undo the modifications to
mm/Kconfig where we made ZONE_DMA dependent on GENERIC_ISA_DMA and set
theses explicitly in each arches Kconfig.

Reviews must occur for each arch in order to determine if ZONE_DMA can be
switched off.  It can only be switched off if we know that all devices
supported by a platform are capable of performing DMA transfers to all of
memory (Some arches already support this: uml, avr32, sh sh64, parisc and
IA64/Altix).

In order to switch ZONE_DMA off conditionally, one would have to establish
a scheme by which one can assure that no drivers are enabled that are only
capable of doing I/O to a part of memory, or one needs to provide an
alternate means of performing an allocation from a specific range of memory
(like provided by alloc_pages_range()) and insure that all drivers use that
call.  In that case the arches alloc_dma_coherent() may need to be modified
to call alloc_pages_range() instead of relying on GFP_DMA.
Signed-off-by: NChristoph Lameter <clameter@sgi.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      5ac6da66
  19. 09 12月, 2006 1 次提交
    • D
      [PATCH] LOG2: Implement a general integer log2 facility in the kernel · f0d1b0b3
      由 David Howells 提交于 
      This facility provides three entry points:

	ilog2()		Log base 2 of unsigned long
	ilog2_u32()	Log base 2 of u32
	ilog2_u64()	Log base 2 of u64

These facilities can either be used inside functions on dynamic data:

	int do_something(long q)
	{
		...;
		y = ilog2(x)
		...;
	}

Or can be used to statically initialise global variables with constant values:

	unsigned n = ilog2(27);

When performing static initialisation, the compiler will report "error:
initializer element is not constant" if asked to take a log of zero or of
something not reducible to a constant.  They treat negative numbers as
unsigned.

When not dealing with a constant, they fall back to using fls() which permits
them to use arch-specific log calculation instructions - such as BSR on
x86/x86_64 or SCAN on FRV - if available.

[akpm@osdl.org: MMC fix]
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: David Howells <dhowells@redhat.com>
Cc: Wojtek Kaniewski <wojtekka@toxygen.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      f0d1b0b3
  21. 30 11月, 2006 1 次提交
  23. 18 10月, 2006 1 次提交
  25. 27 3月, 2006 1 次提交
    • A
      [PATCH] bitops: sparc: use generic bitops · d59288b7
      由 Akinobu Mita 提交于 
      - remove __{,test_and_}{set,clear,change}_bit() and test_bit()
- remove ffz()
- remove __ffs()
- remove sched_find_first_bit()
- remove ffs()
- remove generic_fls()
- remove generic_fls64()
- remove generic_hweight{32,16,8}()
- remove find_{next,first}{,_zero}_bit()
- remove ext2_{set,clear,test,find_first_zero,find_next_zero}_bit()
- remove ext2_{set,clear}_bit_atomic()
- remove minix_{test,set,test_and_clear,test,find_first_zero}_bit()
Signed-off-by: NAkinobu Mita <mita@miraclelinux.com>
Cc: William Lee Irwin III <wli@holomorphy.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      d59288b7
  27. 24 3月, 2006 1 次提交
    • B
      [SPARC]: Try to start getting SMP back into shape. · a54123e2
      由 Bob Breuer 提交于 
      Todo items:
 - IRQ_INPROGRESS flag - use sparc64 irq buckets, or generic irq_desc?
 - sun4d
 - re-indent large chunks of sun4m_smp.c
 - some places assume sequential cpu numbering (i.e. 0,1 instead of 0,2)

Last I checked (with 2.6.14), random programs segfault with dual
HyperSPARC.  And with SuperSPARC II's, it seems stable but will
eventually die from a write lock error (wrong lock owner or something).

I haven't tried the HyperSPARC + highmem combination recently, so that
may still be a problem.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      a54123e2
  29. 09 1月, 2006 1 次提交
  31. 23 12月, 2005 1 次提交
  33. 08 11月, 2005 1 次提交
  35. 11 10月, 2005 1 次提交
  37. 07 10月, 2005 1 次提交
  39. 06 10月, 2005 1 次提交
  41. 08 9月, 2005 1 次提交
    • V
      [PATCH] Kconfig fix (BLK_DEV_FD dependencies) · a08b6b79
      由 viro@ZenIV.linux.org.uk 提交于 
      Sanitized and fixed floppy dependencies: split the messy dependencies for
BLK_DEV_FD by introducing a new symbol (ARCH_MAY_HAVE_PC_FDC), making
BLK_DEV_FD depend on that one and taking declarations of ARCH_MAY_HAVE_PC_FDC
to arch/*/Kconfig.  While we are at it, fixed several obvious cases when
BLK_DEV_FD should have been excluded (architectures lacking asm/floppy.h
are *not* going to have floppy.c compile, let alone work).

If you can come up with better name for that ("this architecture might
have working PC-compatible floppy disk controller"), you are more than
welcome - just s/ARCH_MAY_HAVE_PC_FDC/your_prefered_name/g in the patch
below...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      a08b6b79
  43. 12 7月, 2005 1 次提交
    • S
      [NET]: add a top-level Networking menu to *config · d5950b43
      由 Sam Ravnborg 提交于 
      Create a new top-level menu named "Networking" thus moving
net related options and protocol selection way from the drivers
menu and up on the top-level where they belong.

To implement this all architectures has to source "net/Kconfig" before
drivers/*/Kconfig in their Kconfig file. This change has been
implemented for all architectures.

Device drivers for ordinary NIC's are still to be found
in the Device Drivers section, but Bluetooth, IrDA and ax25
are located with their corresponding menu entries under the new
networking menu item.
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      d5950b43
  45. 29 6月, 2005 1 次提交
  47. 24 6月, 2005 2 次提交
  49. 17 4月, 2005 1 次提交
    • L
      Linux-2.6.12-rc2 · 1da177e4
      由 Linus Torvalds 提交于 
      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!
      1da177e4