Skip to content

L
linux-davinci
Switch branch/tag
  1. 03 Feb, 2010 5 commits
    • anfei zhou's avatar
      mm: flush dcache before writing into page to avoid alias · 931e80e4
      anfei zhou authored 
      The cache alias problem will happen if the changes of user shared mapping
is not flushed before copying, then user and kernel mapping may be mapped
into two different cache line, it is impossible to guarantee the coherence
after iov_iter_copy_from_user_atomic.  So the right steps should be:

	flush_dcache_page(page);
	kmap_atomic(page);
	write to page;
	kunmap_atomic(page);
	flush_dcache_page(page);

More precisely, we might create two new APIs flush_dcache_user_page and
flush_dcache_kern_page to replace the two flush_dcache_page accordingly.

Here is a snippet tested on omap2430 with VIPT cache, and I think it is
not ARM-specific:

	int val = 0x11111111;
	fd = open("abc", O_RDWR);
	addr = mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
	*(addr+0) = 0x44444444;
	tmp = *(addr+0);
	*(addr+1) = 0x77777777;
	write(fd, &val, sizeof(int));
	close(fd);

The results are not always 0x11111111 0x77777777 at the beginning as expected.  Sometimes we see 0x44444444 0x77777777.
Signed-off-by: default avatarAnfei <anfei.zhou@gmail.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: <linux-arch@vger.kernel.org>
Cc: <stable@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      931e80e4
    • Randy Dunlap's avatar
      kfifo: fix kernel-doc notation · bc173f70
      Randy Dunlap authored 
      Fix kfifo kernel-doc warnings:

Warning(kernel/kfifo.c:361): No description found for parameter 'total'
Warning(kernel/kfifo.c:402): bad line:  @ @lenout: pointer to output variable with copied data
Warning(kernel/kfifo.c:412): No description found for parameter 'lenout'
Signed-off-by: default avatarRandy Dunlap <randy.dunlap@oracle.com>
Cc: Stefani Seibold <stefani@seibold.net>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      bc173f70
    • Sergey Matyukevich's avatar
      rtc-fm3130: add missing braces · f4b51628
      Sergey Matyukevich authored 
      Add missing braces for multiline 'if' statements in fm3130_probe.
Signed-off-by: default avatarSergey Matyukevich <geomatsi@gmail.com>
Signed-off-by: default avatarAlessandro Zummo <a.zummo@towertech.it>
Cc: Sergey Lapin <slapin@ossfans.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      f4b51628
    • Alberto Panizzo's avatar
      mx3fb: some debug and initialisation fixes · b3cb5372
      Alberto Panizzo authored 
      Fix the kernel oops when dev_dbg is called with mx3_fbi->txd == NULL

Fix the late initialisation of mx3fb->backlight_level.  If not, in the
chain of function started by init_fb_chan(), in __blank() call
sdc_set_brightness(mx3fb, mx3fb->backlight_level) that will shut down the
CONTRAST PWM output.
Signed-off-by: default avatarAlberto Panizzo <maramaopercheseimorto@gmail.com>
Acked-by: Guennadi Liakhovetski <g.liakhovetski <at> gmx.de>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: <stable@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      b3cb5372
    • Tejun Heo's avatar
      idr: fix a critical misallocation bug · 859ddf09
      Tejun Heo authored 
      Eric Paris located a bug in idr.  With IDR_BITS of 6, it grows to three
layers when id 4096 is first allocated.  When that happens, idr wraps
incorrectly and searches the idr array ignoring the high bits.  The
following test code from Eric demonstrates the bug nicely.

#include <linux/idr.h>
#include <linux/kernel.h>
#include <linux/module.h>

static DEFINE_IDR(test_idr);

int init_module(void)
{
	int ret, forty95, forty96;
	void *addr;

	/* add 2 entries both with 4095 as the start address */
again1:
	if (!idr_pre_get(&test_idr, GFP_KERNEL))
		return -ENOMEM;
	ret = idr_get_new_above(&test_idr, (void *)4095, 4095, &forty95);
	if (ret) {
		if (ret == -EAGAIN)
			goto again1;
		return ret;
	}
	if (forty95 != 4095)
		printk(KERN_ERR "hmmm, forty95=%d\n", forty95);

again2:
	if (!idr_pre_get(&test_idr, GFP_KERNEL))
		return -ENOMEM;
	ret = idr_get_new_above(&test_idr, (void *)4096, 4095, &forty96);
	if (ret) {
		if (ret == -EAGAIN)
			goto again2;
		return ret;
	}
	if (forty96 != 4096)
		printk(KERN_ERR "hmmm, forty96=%d\n", forty96);

	/* try to find the 2 entries, noticing that 4096 broke */
	addr = idr_find(&test_idr, forty95);
	if ((int)addr != forty95)
		printk(KERN_ERR "hmmm, after find forty95=%d addr=%d\n", forty95, (int)addr);
	addr = idr_find(&test_idr, forty96);
	if ((int)addr != forty96)
		printk(KERN_ERR "hmmm, after find forty96=%d addr=%d\n", forty96, (int)addr);
	/* really weird, the entry which should be at 4096 is actually at 0!! */
	addr = idr_find(&test_idr, 0);
	if ((int)addr)
		printk(KERN_ERR "found an entry at id=0 for addr=%d\n", (int)addr);

	idr_remove(&test_idr, forty95);
	idr_remove(&test_idr, forty96);

	return 0;
}

void cleanup_module(void)
{
}

MODULE_AUTHOR("Eric Paris <eparis@redhat.com>");
MODULE_DESCRIPTION("Simple idr test");
MODULE_LICENSE("GPL");

This happens because when sub_alloc() back tracks it doesn't always do it
step-by-step while the over-the-limit detection assumes step-by-step
backtracking.  The logic in sub_alloc() looks like the following.

  restart:
    clear pa[top level + 1] for end cond detection
    l = top level
    while (true) {
	search for empty slot at this level
	if (not found) {
	    push id to the next possible value
	    l++
A:	    if (pa[l] is clear)
	        failed, return asking caller to grow the tree
	    if (going up 1 level gives more slots to search)
	        continue the while loop above with the incremented l
	    else
C:	        goto restart
	}
	adjust id accordingly to the found slot
	if (l == 0)
	    return found id;
	create lower level if not there yet
	record pa[l] and l--
    }

Test A is the fail exit condition but this assumes that failure is
propagated upwared one level at a time but the B optimization path breaks
the assumption and restarts the whole thing with a start value which is
above the possible limit with the current layers.  sub_alloc() assumes the
start id value is inside the limit when called and test A is the only exit
condition check, so it ends up searching for empty slot while ignoring
high set bit.

So, for 4095->4096 test, level0 search fails but pa[1] contains a valid
pointer.  However, going up 1 level wouldn't give any more empty slot so
it takes C and when the whole thing restarts nobody notices the high bit
set beyond the top level.

This patch fixes the bug by changing the fail exit condition check to full
id limit check.

Based-on-patch-from: Eric Paris <eparis@redhat.com>
Reported-by: default avatarEric Paris <eparis@redhat.com>
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Cc: <stable@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      859ddf09
  3. 02 Feb, 2010 14 commits
    • Linus Torvalds's avatar
      Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-block · 1a45dcfe
      Linus Torvalds authored 
      * 'for-linus' of git://git.kernel.dk/linux-2.6-block:
  cfq-iosched: Do not idle on async queues
  blk-cgroup: Fix potential deadlock in blk-cgroup
  block: fix bugs in bio-integrity mempool usage
  block: fix bio_add_page for non trivial merge_bvec_fn case
  drbd: null dereference bug
  drbd: fix max_segment_size initialization
      1a45dcfe
    • Nick Piggin's avatar
      mm: purge fragmented percpu vmap blocks · 02b709df
      Nick Piggin authored 
      Improve handling of fragmented per-CPU vmaps.  We previously don't free
up per-CPU maps until all its addresses have been used and freed.  So
fragmented blocks could fill up vmalloc space even if they actually had
no active vmap regions within them.

Add some logic to allow all CPUs to have these blocks purged in the case
of failure to allocate a new vm area, and also put some logic to trim
such blocks of a current CPU if we hit them in the allocation path (so
as to avoid a large build up of them).

Christoph reported some vmap allocation failures when using the per CPU
vmap APIs in XFS, which cannot be reproduced after this patch and the
previous bug fix.

Cc: linux-mm@kvack.org
Cc: stable@kernel.org
Tested-by: default avatarChristoph Hellwig <hch@infradead.org>
Signed-off-by: default avatarNick Piggin <npiggin@suse.de>
--
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      02b709df
    • Nick Piggin's avatar
      mm: percpu-vmap fix RCU list walking · de560423
      Nick Piggin authored 
      RCU list walking of the per-cpu vmap cache was broken.  It did not use
RCU primitives, and also the union of free_list and rcu_head is
obviously wrong (because free_list is indeed the list we are RCU
walking).

While we are there, remove a couple of unused fields from an earlier
iteration.

These APIs aren't actually used anywhere, because of problems with the
XFS conversion.  Christoph has now verified that the problems are solved
with these patches.  Also it is an exported interface, so I think it
will be good to be merged now (and Christoph wants to get the XFS
changes into their local tree).

Cc: stable@kernel.org
Cc: linux-mm@kvack.org
Tested-by: default avatarChristoph Hellwig <hch@infradead.org>
Signed-off-by: default avatarNick Piggin <npiggin@suse.de>
--
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      de560423
    • Linus Torvalds's avatar
      Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 · 489b24f2
      Linus Torvalds authored 
      * git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  random: Remove unused inode variable
  crypto: padlock-sha - Add import/export support
  random: drop weird m_time/a_time manipulation
      489b24f2
    • Linus Torvalds's avatar
      Merge git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-2.6-fixes · 4dab75ec
      Linus Torvalds authored 
      * git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-2.6-fixes:
  GFS2: Use GFP_NOFS for alloc structure
  GFS2: Fix previous patch
  GFS2: Don't withdraw on partial rindex entries
  GFS2: Fix refcnt leak on gfs2_follow_link() error path
      4dab75ec
    • Linus Torvalds's avatar
      Merge branch 'sh/for-2.6.33' of git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6 · 7fbcca25
      Linus Torvalds authored 
      * 'sh/for-2.6.33' of git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6:
  sh: Fix access to released memory in clk_debugfs_register_one()
  sh: Fix access to released memory in dwarf_unwinder_cleanup()
  usb: r8a66597-hdc disable interrupts fix
  spi: spi_sh_msiof: Fixed data sampling on the correct edge
      7fbcca25
    • Linus Torvalds's avatar
      Merge branch 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus · e770a0f1
      Linus Torvalds authored 
      * 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus:
  MIPS: 64-bit: Detect virtual memory size
  MIPS: AR7: Fix USB slave mem range typo
  MIPS: Alchemy: Fix dbdma ring destruction memory debugcheck.
      e770a0f1
    • Linus Torvalds's avatar
      Fix 'flush_old_exec()/setup_new_exec()' split · 7ab02af4
      Linus Torvalds authored 
      Commit 221af7f8 ("Split 'flush_old_exec' into two functions") split
the function at the point of no return - ie right where there were no
more error cases to check.  That made sense from a technical standpoint,
but when we then also combined it with the actual personality setting
going in between flush_old_exec() and setup_new_exec(), it needs to be a
bit more careful.

In particular, we need to make sure that we really flush the old
personality bits in the 'flush' stage, rather than later in the 'setup'
stage, since otherwise we might be flushing the _new_ personality state
that we're just setting up.

So this moves the flags and personality flushing (and 'flush_thread()',
which is the arch-specific function that generally resets lazy FP state
etc) of the old process into flush_old_exec(), so that it doesn't affect
any state that execve() is setting up for the new process environment.

This was reported by Michal Simek as breaking his Microblaze qemu
environment.
Reported-and-tested-by: default avatarMichal Simek <michal.simek@petalogix.com>
Cc: Peter Anvin <hpa@zytor.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      7ab02af4
    • Vivek Goyal's avatar
      cfq-iosched: Do not idle on async queues · 1efe8fe1
      Vivek Goyal authored 
      Few weeks back, Shaohua Li had posted similar patch. I am reposting it
with more test results.

This patch does two things.

- Do not idle on async queues.

- It also changes the write queue depth CFQ drives (cfq_may_dispatch()).
  Currently, we seem to driving queue depth of 1 always for WRITES. This is
  true even if there is only one write queue in the system and all the logic
  of infinite queue depth in case of single busy queue as well as slowly
  increasing queue depth based on last delayed sync request does not seem to
  be kicking in at all.

This patch will allow deeper WRITE queue depths (subjected to the other
WRITE queue depth contstraints like cfq_quantum and last delayed sync
request).

Shaohua Li had reported getting more out of his SSD. For me, I have got
one Lun exported from an HP EVA and when pure buffered writes are on, I
can get more out of the system. Following are test results of pure
buffered writes (with end_fsync=1) with vanilla and patched kernel. These
results are average of 3 sets of run with increasing number of threads.

AVERAGE[bufwfs][vanilla]
-------
job       Set NR  ReadBW(KB/s)   MaxClat(us)    WriteBW(KB/s)  MaxClat(us)
---       --- --  ------------   -----------    -------------  -----------
bufwfs    3   1   0              0              95349          474141
bufwfs    3   2   0              0              100282         806926
bufwfs    3   4   0              0              109989         2.7301e+06
bufwfs    3   8   0              0              116642         3762231
bufwfs    3   16  0              0              118230         6902970

AVERAGE[bufwfs] [patched kernel]
-------
bufwfs    3   1   0              0              270722         404352
bufwfs    3   2   0              0              206770         1.06552e+06
bufwfs    3   4   0              0              195277         1.62283e+06
bufwfs    3   8   0              0              260960         2.62979e+06
bufwfs    3   16  0              0              299260         1.70731e+06

I also ran buffered writes along with some sequential reads and some
buffered reads going on in the system on a SATA disk because the potential
risk could be that we should not be driving queue depth higher in presence
of sync IO going to keep the max clat low.

With some random and sequential reads going on in the system on one SATA
disk I did not see any significant increase in max clat. So it looks like
other WRITE queue depth control logic is doing its job. Here are the
results.

AVERAGE[brr, bsr, bufw together] [vanilla]
-------
job       Set NR  ReadBW(KB/s)   MaxClat(us)    WriteBW(KB/s)  MaxClat(us)
---       --- --  ------------   -----------    -------------  -----------
brr       3   1   850            546345         0              0
bsr       3   1   14650          729543         0              0
bufw      3   1   0              0              23908          8274517

brr       3   2   981.333        579395         0              0
bsr       3   2   14149.7        1175689        0              0
bufw      3   2   0              0              21921          1.28108e+07

brr       3   4   898.333        1.75527e+06    0              0
bsr       3   4   12230.7        1.40072e+06    0              0
bufw      3   4   0              0              19722.3        2.4901e+07

brr       3   8   900            3160594        0              0
bsr       3   8   9282.33        1.91314e+06    0              0
bufw      3   8   0              0              18789.3        23890622

AVERAGE[brr, bsr, bufw mixed] [patched kernel]
-------
job       Set NR  ReadBW(KB/s)   MaxClat(us)    WriteBW(KB/s)  MaxClat(us)
---       --- --  ------------   -----------    -------------  -----------
brr       3   1   837            417973         0              0
bsr       3   1   14357.7        591275         0              0
bufw      3   1   0              0              24869.7        8910662

brr       3   2   1038.33        543434         0              0
bsr       3   2   13351.3        1205858        0              0
bufw      3   2   0              0              18626.3        13280370

brr       3   4   913            1.86861e+06    0              0
bsr       3   4   12652.3        1430974        0              0
bufw      3   4   0              0              15343.3        2.81305e+07

brr       3   8   890            2.92695e+06    0              0
bsr       3   8   9635.33        1.90244e+06    0              0
bufw      3   8   0              0              17200.3        24424392

So looks like it might make sense to include this patch.

Thanks
Vivek
Signed-off-by: default avatarVivek Goyal <vgoyal@redhat.com>
Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
      1efe8fe1
    • Guenter Roeck's avatar
      MIPS: 64-bit: Detect virtual memory size · 91dfc423
      Guenter Roeck authored 
      Linux kernel 2.6.32 and later allocate address space from the top of the
kernel virtual memory address space.

This patch implements virtual memory size detection for 64 bit MIPS CPUs
to avoid resulting crashes.
Signed-off-by: default avatarGuenter Roeck <guenter.roeck@ericsson.com>
Cc: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/935/Reviewed-by: default avatarDavid Daney <ddaney@caviumnetworks.com>
Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
      91dfc423
    • Marek Skuczynski's avatar
      sh: Fix access to released memory in clk_debugfs_register_one() · bc10e875
      Marek Skuczynski authored 
      Signed-off-by: default avatarMarek Skuczynski <mareksk7@gmail.com>
Signed-off-by: default avatarPaul Mundt <lethal@linux-sh.org>
      bc10e875
    • Marek Skuczynski's avatar
      sh: Fix access to released memory in dwarf_unwinder_cleanup() · 00b3e0a2
      Marek Skuczynski authored 
      Signed-off-by: default avatarMarek Skuczynski <mareksk7@gmail.com>
Acked-by: default avatarMatt Fleming <matt@console-pimps.org>
Signed-off-by: default avatarPaul Mundt <lethal@linux-sh.org>
      00b3e0a2
    • Magnus Damm's avatar
      usb: r8a66597-hdc disable interrupts fix · e5ff15be
      Magnus Damm authored 
      This patch improves disable_controller() in the r8a66597-hdc
driver to disable all interrupts and clear status flags. It
also makes sure that disable_controller() is called during
probe(). This fixes the relatively rare case of unexpected
pending interrupts after kexec reboot.
Signed-off-by: default avatarMagnus Damm <damm@opensource.se>
Acked-by: default avatarYoshihiro Shimoda <shimoda.yoshihiro@renesas.com>
Signed-off-by: default avatarPaul Mundt <lethal@linux-sh.org>
      e5ff15be
    • Markus Pietrek's avatar
      spi: spi_sh_msiof: Fixed data sampling on the correct edge · e8708ef7
      Markus Pietrek authored 
      The spi_sh_msiof.c driver presently misconfigures REDG and TEDG. TEDG==0
outputs data at the **rising edge** of the clock and REDG==0 samples data
at the **falling edge** of the clock. Therefore for SPI, TEDG must be
equal to REDG, otherwise the last byte received is not sampled in SPI
mode 3.

This brings the driver in line with the SH7723 HW Reference Manual
settings documented in Figures 20.20 and 20.21 ("SPI Clock and data
timing").
Signed-off-by: default avatarMarkus Pietrek <Markus.Pietrek@emtrion.de>
Acked-by: default avatarMagnus Damm <damm@opensource.se>
Signed-off-by: default avatarPaul Mundt <lethal@linux-sh.org>
      e8708ef7
  5. 01 Feb, 2010 21 commits