Commit Graph

2952 Commits

Author SHA1 Message Date
Thomas Gleixner
9a57d470fd [MTD] NAND ECC hwctl function has no return value
Fix the broken prototype

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2006-05-23 15:58:23 +02:00
Thomas Gleixner
4cbb9b80e1 Merge branch 'master' of /home/tglx/work/kernel/git/mtd-2.6/
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2006-05-23 12:37:31 +02:00
Thomas Gleixner
6dfc6d250d [MTD] NAND modularize ECC
First step of modularizing ECC support.
- Move ECC related functionality into a seperate embedded data structure
- Get rid of the hardware dependend constants to simplify new ECC models

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2006-05-23 12:00:46 +02:00
Thomas Gleixner
58dd8f2bfd [MTD] NAND consolidate data types
The NAND driver used a mix of unsigned char, u_char amd uint8_t
data types. Consolidate to uint8_t usage

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2006-05-23 11:52:35 +02:00
Thomas Gleixner
2c0a2bed92 [MTD] NAND whitespace and formatting cleanup
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2006-05-23 11:50:56 +02:00
Thomas Gleixner
ce4c61f184 [MTD] Add support for NDFC NAND controller
NDFC NAND Flash controller is embedded in PPC EP44x SoCs.
Add platform driver based support.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2006-05-23 11:43:28 +02:00
Thomas Gleixner
41796c2ea9 [MTD] Add platform support for NAND
Add the data structures necessary to provide platform device support
for NAND

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2006-05-23 11:38:59 +02:00
Thomas Gleixner
a36ed2995c [MTD] Simplify NAND locking
Replace the chip lock by a the controller lock. For simple drivers a
dummy controller structure is created by the scan code.
This simplifies the locking algorithm in nand_get/release_chip().

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2006-05-23 11:37:03 +02:00
Joern Engel
28318776a8 [MTD] Introduce writesize
At least two flashes exists that have the concept of a minimum write unit,
similar to NAND pages, but no other NAND characteristics.  Therefore, rename
the minimum write unit to "writesize" for all flashes, including NAND.

Signed-off-by: Joern Engel <joern@wh.fh-wedel.de>
2006-05-22 23:18:05 +02:00
David Woodhouse
0cfc7da3ff Merge git://git.infradead.org/jffs2-xattr-2.6
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-05-20 17:27:32 +01:00
David Woodhouse
aef9ab4784 [JFFS2] Support new device nodes
Device node major/minor numbers are just stored in the payload of a single
data node. Just extend that to 4 bytes and use new_encode_dev() for it.

We only use the 4-byte format if we _need_ to, if !old_valid_dev(foo).
This preserves backwards compatibility with older code as much as
possible. If we do make devices with major or minor numbers above 255, and
then mount the file system with the old code, it'll just read the first
two bytes and get the numbers wrong. If it comes to garbage-collect it,
it'll then write back those wrong numbers. But that's about the best we
can expect.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-05-19 00:28:49 +01:00
KaiGai Kohei
20a92fc74c Merge git://git.infradead.org/mtd-2.6 2006-05-19 00:43:53 +09:00
David Woodhouse
ba9627b85f [JFFS2] Repack some on-medium structures. ARM is weirder than I thought.
We have to pack at least the jint16_t structure, because otherwise it'll
be four bytes in size. Thankfully, we can do that and _not_ pack the
actual node structures, and the compiler still doesn't emit stupid code.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-05-16 23:03:08 +01:00
David Woodhouse
18594822fc Merge git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-05-16 01:19:52 +01:00
Hua Zhong
e6333fd4dd [PATCH] fix can_share_swap_page() when !CONFIG_SWAP
can_share_swap_page() is used to check if the page has the last reference.
This avoids allocating a new page for COW if it's the last page.

However, if CONFIG_SWAP is not set, can_share_swap_page() is defined as 0,
thus always causes a copy for the last COW page.  The below simple patch
fixes it.

Signed-off-by: Hua Zhong <hzhong@gmail.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-05-15 11:20:56 -07:00
Mike Kravetz
39d24e6426 [PATCH] add slab_is_available() routine for boot code
slab_is_available() indicates slab based allocators are available for use.
SPARSEMEM code needs to know this as it can be called at various times
during the boot process.

Signed-off-by: Mike Kravetz <kravetz@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-05-15 11:20:56 -07:00
Trent Piepho
5e37661389 [PATCH] symbol_put_addr() locks kernel
Even since a previous patch:

Fix race between CONFIG_DEBUG_SLABALLOC and modules
Sun, 27 Jun 2004 17:55:19 +0000 (17:55 +0000)
http://www.kernel.org/git/?p=linux/kernel/git/torvalds/old-2.6-bkcvs.git;a=commit;h=92b3db26d31cf21b70e3c1eadc56c179506d8fbe

The function symbol_put_addr() will deadlock the kernel.

symbol_put_addr() would acquire modlist_lock, then while holding the lock call
two functions kernel_text_address() and module_text_address() which also try
to acquire the same lock.  This deadlocks the kernel of course.

This patch changes symbol_put_addr() to not acquire the modlist_lock, it
doesn't need it since it never looks at the module list directly.  Also, it
now uses core_kernel_text() instead of kernel_text_address().  The latter has
an additional check for addr inside a module, but we don't need to do that
since we call module_text_address() (the same function kernel_text_address
uses) ourselves.

Signed-off-by: Trent Piepho <xyzzy@speakeasy.org>
Cc: Zwane Mwaikambo <zwane@fsmlabs.com>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-05-15 11:20:55 -07:00
Heiko Carstens
986733e01d [PATCH] RCU: introduce rcu_needs_cpu() interface
With "Paul E. McKenney" <paulmck@us.ibm.com>

Introduce rcu_needs_cpu() interface.  This can be used to tell if there
will be a new rcu batch on a cpu soon by looking at the curlist pointer.
This can be used to avoid to enter a tickless idle state where the cpu
would miss that a new batch is ready when rcu_start_batch would be called
on a different cpu.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-05-15 11:20:55 -07:00
David Woodhouse
3e68fbb59b [JFFS2] Don't pack on-medium structures, because GCC emits crappy code
If we use __attribute__((packed)), GCC will _also_ assume that the
structures aren't sensibly aligned, and it'll emit code to cope with
that instead of straight word load/save. This can be _very_ suboptimal
on architectures like ARM.

Ideally, we want an attribute which just tells GCC not to do any
padding, without the alignment side-effects. In the absense of that,
we'll just drop the 'packed' attribute and hope that everything stays as
it was (which to be fair is fairly much what we expect). And add some
paranoia checks in the initialisation code, which should be optimised
away completely in the normal case.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-05-15 00:49:43 +01:00
David Woodhouse
0d4e30d26a [MTD] Clean up <linux/mtd/physmap.h> to fix modular build
... and also fix the multiple inclusion guard so it actually _works_

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-05-14 12:25:19 +01:00
David Woodhouse
151e76590f [MTD] Fix legacy character sets throughout drivers/mtd, include/linux/mtd
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-05-14 01:51:54 +01:00
KaiGai Kohei
aa98d7cf59 [JFFS2][XATTR] XATTR support on JFFS2 (version. 5)
This attached patches provide xattr support including POSIX-ACL and
SELinux support on JFFS2 (version.5).

There are some significant differences from previous version posted
at last December.
The biggest change is addition of EBS(Erase Block Summary) support.
Currently, both kernel and usermode utility (sumtool) can recognize
xattr nodes which have JFFS2_NODETYPE_XATTR/_XREF nodetype.

In addition, some bugs are fixed.
- A potential race condition was fixed.
- Unexpected fail when updating a xattr by same name/value pair was fixed.
- A bug when removing xattr name/value pair was fixed.

The fundamental structures (such as using two new nodetypes and exclusion
mechanism by rwsem) are unchanged. But most of implementation were reviewed
and updated if necessary.
Espacially, we had to change several internal implementations related to
load_xattr_datum() to avoid a potential race condition.

[1/2] xattr_on_jffs2.kernel.version-5.patch
[2/2] xattr_on_jffs2.utils.version-5.patch

Signed-off-by: KaiGai Kohei <kaigai@ak.jp.nec.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-05-13 15:09:47 +09:00
Kyungmin Park
493c646077 OneNAND: One-Time Programmable (OTP) support
One Block of the NAND Flash Array memory is reserved as
a One-Time Programmable Block memory area.
Also, 1st Block of NAND Flash Array can be used as OTP.

The OTP block can be read, programmed and locked using the same
operations as any other NAND Flash Array memory block.
OTP block cannot be erased.

OTP block is fully-guaranteed to be a valid block.

Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
2006-05-12 15:35:50 +01:00
Kyungmin Park
9c01f87db1 OneNAND: handle byte access on BufferRAM
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
2006-05-12 15:35:45 +01:00
Linus Torvalds
2bf9d6d0f2 Merge master.kernel.org:/home/rmk/linux-2.6-serial
* master.kernel.org:/home/rmk/linux-2.6-serial:
  [SERIAL] 8250: add locking to console write function
  [SERIAL] Remove unconditional enable of TX irq for console
  [SERIAL] 8250: set divisor register correctly for AMD Alchemy SoC uart
  [SERIAL] AMD Alchemy UART: claim memory range
  [SERIAL] Clean up serial locking when obtaining a reference to a port
2006-05-11 15:46:42 -07:00
Linus Torvalds
6572b2064a Merge master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
* master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6:
  [NET_SCHED]: HFSC: fix thinko in hfsc_adjust_levels()
  [IPV6]: skb leakage in inet6_csk_xmit
  [BRIDGE]: Do sysfs registration inside rtnl.
  [NET]: Do sysfs registration as part of register_netdevice.
  [TG3]: Fix possible NULL deref in tg3_run_loopback().
  [NET] linkwatch: Handle jiffies wrap-around
  [IRDA]: Switching to a workqueue for the SIR work
  [IRDA]: smsc-ircc: Minimal hotplug support.
  [IRDA]: Removing unused EXPORT_SYMBOLs
  [IRDA]: New maintainer.
  [NET]: Make netdev_chain a raw notifier.
  [IPV4]: ip_options_fragment() has no effect on fragmentation
  [NET]: Add missing operstates documentation.
2006-05-11 15:35:54 -07:00
Linus Torvalds
6314410dd1 Merge branch 'upstream' of master.kernel.org:/pub/scm/linux/kernel/git/shemminger/netdev-2.6
* 'upstream' of master.kernel.org:/pub/scm/linux/kernel/git/shemminger/netdev-2.6:
  sis900: phy for FoxCon motherboard
  dl2k: use DMA_48BIT_MASK constant
  phy: mdiobus_register(): initialize all phy_map entries
  sky2: ifdown kills irq mask
2006-05-10 14:59:29 -07:00
Francois Romieu
4c1b46226c dl2k: use DMA_48BIT_MASK constant
Typo will be harder with this one.

Signed-off-by: Francois Romieu <romieu@fr.zoreil.com>
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
2006-05-10 14:04:22 -07:00
Stephen Hemminger
b17a7c179d [NET]: Do sysfs registration as part of register_netdevice.
The last step of netdevice registration was being done by a delayed
call, but because it was delayed, it was impossible to return any error
code if the class_device registration failed.

Side effects:
 * one state in registration process is unnecessary.
 * register_netdevice can sleep inside class_device registration/hotplug
 * code in netdev_run_todo only does unregistration so it is simpler.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-05-10 13:21:17 -07:00
Stephen Hemminger
d324031245 sky2: backout NAPI reschedule
This is a backout of earlier patch.

The whole rescheduling hack was a bad idea. It doesn't really solve
the problem and it makes the code more complicated for no good reason.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
2006-05-08 16:00:23 -07:00
David Woodhouse
6f18a022fb Finally remove the obnoxious inter_module_xxx()
This was already a bad plan when I argued against adding it in the first
place. Good riddance.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-05-08 22:40:05 +01:00
Lennert Buytenhek
73566edf9b [MTD] Convert physmap to platform driver
After dwmw2 let me know it ought to be done, I rewrote the physmap map
driver to be a platform driver.  I know zilch about the driver model,
so I probably botched it in some way, but I've done some tests on an
ixp23xx board which uses physmap, and it all seems to work.

In order to not break existing physmap users, I've added some compat
code that will instantiate a platform device iff CONFIG_MTD_PHYSMAP_LEN
is defined and != 0.  Also, I've changed the default value for
CONFIG_MTD_PHYSMAP_LEN to zero, so that people who inadvertently
compile in physmap (or new, platform-style, users of physmap) don't get
burned.

This works pretty well -- the new physmap driver is a drop-in replacement
for the old one, and works on said ixp23xx board without any code changes
needed.  (This should hold as long as users don't touch 'physmap_map'
directly.)

Once all physmap users have been converted to instantiate their own
platform devices, the compat code can go.  (Or we decide that we can
change all the in-tree users at the same time, and never merge the
compat code.)

Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-05-07 17:16:36 +01:00
Stephen Hemminger
fe9925b551 [NET]: Create netdev attribute_groups with class_device_add
Atomically create attributes when class device is added. This avoids
the race between registering class_device (which generates hotplug
event), and the creation of attribute groups.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-05-06 17:56:03 -07:00
Stephen Hemminger
1498221d51 [CLASS DEVICE]: add attribute_group creation
Extend the support of attribute groups in class_device's to allow
groups to be created as part of the registration process. This allows
network device's to avoid race between registration and creating
groups.

Note that unlike attributes that are a property of the class object,
the groups are a property of the class_device object. This is done
because there are different types of network devices (wireless for
example).

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-05-06 17:55:11 -07:00
Linus Torvalds
d98550e334 Merge branch 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc
* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc:
  [PATCH] powerpc: Use the ibm,pa-features property if available
  powerpc: Fix incorrect might_sleep in __get_user/__put_user on kernel addresses
  [PATCH] ppc32 CPM_UART: fixes and improvements
  [PATCH] ppc32 CPM_UART: Fixed break send on SCC
  [PATCH] powerpc/kprobes: fix singlestep out-of-line
  [PATCH] powerpc/pseries: avoid crash in PCI code if mem system not up
2006-05-04 15:09:52 -07:00
Linus Torvalds
6fc56ccfe4 Merge master.kernel.org:/home/rmk/linux-2.6-mmc
* master.kernel.org:/home/rmk/linux-2.6-mmc:
  [MMC] Move set_ios debugging into mmc.c
  [MMC] Correct mmc_request_done comments
  [MMC] PXA: reduce the number of lines PXAMCI debug uses
  [MMC] PXA and i.MX: don't avoid sending stop command on error
  [MMC] extend data timeout for writes
  [ARM] 3485/1: i.MX: MX1 SD/MMC fix of unintentional double start possibility
2006-05-04 14:52:27 -07:00
Linus Torvalds
cbdf811c77 Merge branch 'splice' of git://brick.kernel.dk/data/git/linux-2.6-block
* 'splice' of git://brick.kernel.dk/data/git/linux-2.6-block:
  [PATCH] compat_sys_vmsplice: one-off in UIO_MAXIOV check
  [PATCH] splice: redo page lookup if add_to_page_cache() returns -EEXIST
  [PATCH] splice: rename remaining info variables to pipe
  [PATCH] splice: LRU fixups
  [PATCH] splice: fix unlocking of page on error ->prepare_write()
2006-05-04 13:25:40 -04:00
Jing Min Zhao
7582e9d17e [NETFILTER]: H.323 helper: Change author's email address
Signed-off-by: Jing Min Zhao <zhaojingmin@users.sourceforge.net>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-05-03 23:19:59 -07:00
Jens Axboe
1432873af7 [PATCH] splice: LRU fixups
Nick says that the current construct isn't safe. This goes back to the
original, but sets PIPE_BUF_FLAG_LRU on user pages as well as they all
seem to be on the LRU in the first place.

Signed-off-by: Jens Axboe <axboe@suse.de>
2006-05-04 06:55:12 +02:00
Vitaly Bordug
6e1976961c [PATCH] ppc32 CPM_UART: fixes and improvements
A number of small issues are fixed, and added the header file, missed from the
original series. With this, driver should be pretty stable as tested among
both platform-device-driven and "old way" boards. Also added missing GPL
statement , and updated year field on existing ones to reflect
code update.

Signed-off-by: Vitaly Bordug <vbordug@ru.mvista.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-05-03 23:06:44 +10:00
David Woodhouse
edc4ff7c08 Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6 2006-05-03 13:30:35 +01:00
David Woodhouse
cbb9a56177 Move jffs2_fs_i.h and jffs2_fs_sb.h from include/linux/ to fs/jffs2/
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
2006-05-03 13:07:27 +01:00
Russell King
37be4e7809 [MMC] extend data timeout for writes
The CSD contains a "read2write factor" which determines the multiplier to
be applied to the read timeout to obtain the write timeout.  We were
ignoring this parameter, resulting in the possibility for writes being
timed out too early.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-05-02 17:24:59 +01:00
Jens Axboe
330ab71619 [PATCH] vmsplice: restrict stealing a little more
Apply the same rules as the anon pipe pages, only allow stealing
if no one else is using the page.

Signed-off-by: Jens Axboe <axboe@suse.de>
2006-05-02 15:29:57 +02:00
Jens Axboe
a893b99be7 [PATCH] splice: fix page LRU accounting
Currently we rely on the PIPE_BUF_FLAG_LRU flag being set correctly
to know whether we need to fiddle with page LRU state after stealing it,
however for some origins we just don't know if the page is on the LRU
list or not.

So remove PIPE_BUF_FLAG_LRU and do this check/add manually in pipe_to_file()
instead.

Signed-off-by: Jens Axboe <axboe@suse.de>
2006-05-02 15:03:27 +02:00
Linus Torvalds
532f57da40 Merge branch 'audit.b10' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit-current
* 'audit.b10' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit-current:
  [PATCH] Audit Filter Performance
  [PATCH] Rework of IPC auditing
  [PATCH] More user space subject labels
  [PATCH] Reworked patch for labels on user space messages
  [PATCH] change lspp ipc auditing
  [PATCH] audit inode patch
  [PATCH] support for context based audit filtering, part 2
  [PATCH] support for context based audit filtering
  [PATCH] no need to wank with task_lock() and pinning task down in audit_syscall_exit()
  [PATCH] drop task argument of audit_syscall_{entry,exit}
  [PATCH] drop gfp_mask in audit_log_exit()
  [PATCH] move call of audit_free() into do_exit()
  [PATCH] sockaddr patch
  [PATCH] deal with deadlocks in audit_free()
2006-05-01 21:43:05 -07:00
Patrick McHardy
46c5ea3c9a [NETFILTER] x_tables: fix compat related crash on non-x86
When iptables userspace adds an ipt_standard_target, it calculates the size
of the entire entry as:

sizeof(struct ipt_entry) + XT_ALIGN(sizeof(struct ipt_standard_target))

ipt_standard_target looks like this:

  struct xt_standard_target
  {
        struct xt_entry_target target;
        int verdict;
  };

xt_entry_target contains a pointer, so when compiled for 64 bit the
structure gets an extra 4 byte of padding at the end. On 32 bit
architectures where iptables aligns to 8 byte it will also have 4
byte padding at the end because it is only 36 bytes large.

The compat_ipt_standard_fn in the kernel adjusts the offsets by

  sizeof(struct ipt_standard_target) - sizeof(struct compat_ipt_standard_target),

which will always result in 4, even if the structure from userspace
was already padded to a multiple of 8. On x86 this works out by
accident because userspace only aligns to 4, on all other
architectures this is broken and causes incorrect adjustments to
the size and following offsets.

Thanks to Linus for lots of debugging help and testing.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-05-01 20:48:32 -07:00
Linus Torvalds
9817d207dc Merge branch 'splice' of git://brick.kernel.dk/data/git/linux-2.6-block
* 'splice' of git://brick.kernel.dk/data/git/linux-2.6-block:
  [PATCH] vmsplice: allow user to pass in gift pages
  [PATCH] pipe: enable atomic copying of pipe data to/from user space
  [PATCH] splice: call handle_ra_miss() on failure to lookup page
  [PATCH] Add ->splice_read/splice_write to def_blk_fops
  [PATCH] pipe: introduce ->pin() buffer operation
  [PATCH] splice: fix bugs in pipe_to_file()
  [PATCH] splice: fix bugs with stealing regular pipe pages
2006-05-01 18:33:40 -07:00
Jens Axboe
7afa6fd037 [PATCH] vmsplice: allow user to pass in gift pages
If SPLICE_F_GIFT is set, the user is basically giving this pages away to
the kernel. That means we can steal them for eg page cache uses instead
of copying it.

The data must be properly page aligned and also a multiple of the page size
in length.

Signed-off-by: Jens Axboe <axboe@suse.de>
2006-05-01 20:02:33 +02:00
Jens Axboe
f6762b7ad8 [PATCH] pipe: enable atomic copying of pipe data to/from user space
The pipe ->map() method uses kmap() to virtually map the pages, which
is both slow and has known scalability issues on SMP. This patch enables
atomic copying of pipe pages, by pre-faulting data and using kmap_atomic()
instead.

lmbench bw_pipe and lat_pipe measurements agree this is a Good Thing. Here
are results from that on a UP machine with highmem (1.5GiB of RAM), running
first a UP kernel, SMP kernel, and SMP kernel patched.

Vanilla-UP:
Pipe bandwidth: 1622.28 MB/sec
Pipe bandwidth: 1610.59 MB/sec
Pipe bandwidth: 1608.30 MB/sec
Pipe latency: 7.3275 microseconds
Pipe latency: 7.2995 microseconds
Pipe latency: 7.3097 microseconds

Vanilla-SMP:
Pipe bandwidth: 1382.19 MB/sec
Pipe bandwidth: 1317.27 MB/sec
Pipe bandwidth: 1355.61 MB/sec
Pipe latency: 9.6402 microseconds
Pipe latency: 9.6696 microseconds
Pipe latency: 9.6153 microseconds

Patched-SMP:
Pipe bandwidth: 1578.70 MB/sec
Pipe bandwidth: 1579.95 MB/sec
Pipe bandwidth: 1578.63 MB/sec
Pipe latency: 9.1654 microseconds
Pipe latency: 9.2266 microseconds
Pipe latency: 9.1527 microseconds

Signed-off-by: Jens Axboe <axboe@suse.de>
2006-05-01 20:02:05 +02:00