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  1. 20 10月, 2007 33 次提交
  3. 19 10月, 2007 7 次提交
    • I
      x86: fix global_flush_tlb() bug · 9a24d04a
      由 Ingo Molnar 提交于 
      While we were reviewing pageattr_32/64.c for unification,
Thomas Gleixner noticed the following serious SMP bug in
global_flush_tlb():

	down_read(&init_mm.mmap_sem);
	list_replace_init(&deferred_pages, &l);
	up_read(&init_mm.mmap_sem);

this is SMP-unsafe because list_replace_init() done on two CPUs in
parallel can corrupt the list.

This bug has been introduced about a year ago in the 64-bit tree:

       commit ea7322de
       Author: Andi Kleen <ak@suse.de>
       Date:   Thu Dec 7 02:14:05 2006 +0100

       [PATCH] x86-64: Speed and clean up cache flushing in change_page_attr

                down_read(&init_mm.mmap_sem);
        -       dpage = xchg(&deferred_pages, NULL);
        +       list_replace_init(&deferred_pages, &l);
                up_read(&init_mm.mmap_sem);

the xchg() based version was SMP-safe, but list_replace_init() is not.
So this "cleanup" introduced a nasty bug.

why this bug never become prominent is a mystery - it can probably be
explained with the (still) relative obscurity of the x86_64 architecture.

the safe fix for now is to write-lock init_mm.mmap_sem.
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      9a24d04a
    • R
      Replace __attribute_pure__ with __pure · e8c44319
      由 Ralf Baechle 提交于 
      To be consistent with the use of attributes in the rest of the kernel
replace all use of __attribute_pure__ with __pure and delete the definition
of __attribute_pure__.
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Acked-by: NMauro Carvalho Chehab <mchehab@infradead.org>
Cc: Bryan Wu <bryan.wu@analog.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      e8c44319
    • S
      sparse pointer use of zero as null · c80544dc
      由 Stephen Hemminger 提交于 
      Get rid of sparse related warnings from places that use integer as NULL
pointer.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: NStephen Hemminger <shemminger@linux-foundation.org>
Cc: Andi Kleen <ak@suse.de>
Cc: Jeff Garzik <jeff@garzik.org>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Ian Kent <raven@themaw.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Davide Libenzi <davidel@xmailserver.org>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      c80544dc
    • S
      x86 msr driver: Misc cpuinit annotations · 38048983
      由 Satyam Sharma 提交于 
      msr_class_cpu_callback() can be marked __cpuinit, being the notifier callback
for a __cpuinitdata notifier_block.  So can be marked msr_device_create() too,
called only from the newly-__cpuinit msr_class_cpu_callback() or from
__init-marked msr_init().
Signed-off-by: NSatyam Sharma <satyam@infradead.org>
Cc: Andi Kleen <ak@suse.de>
Acked-by: NH. Peter Anvin <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      38048983
    • M
      powerpc: add scaled time accounting · 4603ac18
      由 Michael Neuling 提交于 
      This adds POWERPC specific hooks for scaled time accounting.

POWER6 includes a SPURR register.  The SPURR is based off the PURR register
but is scaled based on CPU frequency and issue rates.  This gives a more
accurate account of the instructions used per task.  The PURR and timebase
will be constant relative to the wall clock, irrespective of the CPU
frequency.

This implementation reads the SPURR register in account_system_vtime which
is only call called on context witch and hard and soft irq entry and exit.
The percentage of user and system time is then estimated using the ratio of
these accounted by the PURR.  If the SPURR is not present, the PURR read.

An earlier implementation of this patch read the SPURR whenever the PURR
was read, which included the system call entry and exit path.
Unfortunately this showed a performance regression on lmbench runs, so was
re-implemented.

I've included the lmbench results here when run bare metal on POWER6.  1st
column is the unpatch results.  2nd column is the results using the below
patch and the 3rd is the % diff of these results from the base.  4th and
5th columns are the results and % differnce from the base using the older
patch (SPURR read in syscall entry/exit path).

                              Base        Scaled-Acct     SPURR-in-syscall
                             Result      Result  % diff    Result % diff
Simple syscall:              0.3086      0.3086  0.0000    0.3452 11.8600
Simple read:                 0.4591      0.4671  1.7425    0.5044 9.86713
Simple write:                0.4364      0.4366  0.0458    0.4731 8.40971
Simple stat:                 2.0055      2.0295  1.1967    2.0669 3.06158
Simple fstat:                0.5962      0.5876  -1.442    0.6368 6.80979
Simple open/close:           3.1283      3.1009  -0.875    3.2088 2.57328
Select on 10 fd's:           0.8554      0.8457  -1.133    0.8667 1.32101
Select on 100 fd's:          3.5292      3.6329  2.9383    3.6664 3.88756
Select on 250 fd's:          7.9097      8.1881  3.5197    8.2242 3.97613
Select on 500 fd's:          15.2659     15.836  3.7357    15.873 3.97814
Select on 10 tcp fd's:       0.9576      0.9416  -1.670    0.9752 1.83792
Select on 100 tcp fd's:      7.248       7.2254  -0.311    7.2685 0.28283
Select on 250 tcp fd's:      17.7742     17.707  -0.375    17.749 -0.1406
Select on 500 tcp fd's:      35.4258     35.25   -0.496    35.286 -0.3929
Signal handler installation: 0.6131      0.6075  -0.913    0.647  5.52927
Signal handler overhead:     2.0919      2.1078  0.7600    2.1831 4.35967
Protection fault:            0.7345      0.7478  1.8107    0.8031 9.33968
Pipe latency:                33.006      16.398  -50.31    33.475 1.42368
AF_UNIX sock stream latency: 14.5093     30.910  113.03    30.715 111.692
Process fork+exit:           219.8       222.8   1.3648    229.37 4.35623
Process fork+execve:         876.14      873.28  -0.32     868.66 -0.8533
Process fork+/bin/sh -c:     2830        2876.5  1.6431    2958   4.52296
File /var/tmp/XXX write bw:  1193497     1195536 0.1708    118657 -0.5799
Pagefaults on /var/tmp/XXX:  3.1272      3.2117  2.7020    3.2521 3.99398

Also, kernel compile times show no difference with this patch applied.

[pbadari@us.ibm.com: Avoid unnecessary PURR reading]
Signed-off-by: NMichael Neuling <mikey@neuling.org>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Jay Lan <jlan@engr.sgi.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NBadari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      4603ac18
    • J
      Add missing newlines to some uses of dev_<level> messages · 898eb71c
      由 Joe Perches 提交于 
      Found these while looking at printk uses.

Add missing newlines to dev_<level> uses
Add missing KERN_<level> prefixes to multiline dev_<level>s
Fixed a wierd->weird spelling typo
Added a newline to a printk
Signed-off-by: NJoe Perches <joe@perches.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Mark M. Hoffman <mhoffman@lightlink.com>
Cc: Roland Dreier <rolandd@cisco.com>
Cc: Tilman Schmidt <tilman@imap.cc>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Jeff Garzik <jeff@garzik.org>
Cc: Stephen Hemminger <shemminger@linux-foundation.org>
Cc: Greg KH <greg@kroah.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Cc: James Smart <James.Smart@Emulex.Com>
Cc: Andrew Vasquez <andrew.vasquez@qlogic.com>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Jaroslav Kysela <perex@suse.cz>
Cc: Takashi Iwai <tiwai@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      898eb71c
    • E
      sysctl: x86_64 remove unnecessary binary paths · 282a821f
      由 Eric W. Biederman 提交于 
      Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Cc: Alexey Dobriyan <adobriyan@sw.ru>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      282a821f