Inspection is proving insufficient to catch all RCU misuses,
which is understandable given that rcu_dereference() might be
protected by any of four different flavors of RCU (RCU, RCU-bh,
RCU-sched, and SRCU), and might also/instead be protected by any
of a number of locking primitives. It is therefore time to
enlist the aid of lockdep.
This set of patches is inspired by earlier work by Peter
Zijlstra and Thomas Gleixner, and takes the following approach:
o Set up separate lockdep classes for RCU, RCU-bh, and RCU-sched.
o Set up separate lockdep classes for each instance of SRCU.
o Create primitives that check for being in an RCU read-side
critical section. These return exact answers if lockdep is
fully enabled, but if unsure, report being in an RCU read-side
critical section. (We want to avoid false positives!)
The primitives are:
For RCU: rcu_read_lock_held(void)
For RCU-bh: rcu_read_lock_bh_held(void)
For RCU-sched: rcu_read_lock_sched_held(void)
For SRCU: srcu_read_lock_held(struct srcu_struct *sp)
o Add rcu_dereference_check(), which takes a second argument
in which one places a boolean expression based on the above
primitives and/or lockdep_is_held().
o A new kernel configuration parameter, CONFIG_PROVE_RCU, enables
rcu_dereference_check(). This depends on CONFIG_PROVE_LOCKING,
and should be quite helpful during the transition period while
CONFIG_PROVE_RCU-unaware patches are in flight.
The existing rcu_dereference() primitive does no checking, but
upcoming patches will change that.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: mathieu.desnoyers@polymtl.ca
Cc: josh@joshtriplett.org
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
Cc: Valdis.Kletnieks@vt.edu
Cc: dhowells@redhat.com
LKML-Reference: <1266887105-1528-1-git-send-email-paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This reverts commit fb1e75389b.
"Benjamin S." <sbenni@gmx.de> reports that the patch in question
causes a big drop in sequential throughput for him, dropping from
200MB/sec down to only 70MB/sec.
Needs to be investigated more fully, for now lets just revert the
offending commit.
Conflicts:
include/linux/blkdev.h
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6:
CacheFiles: Fix a race in cachefiles_delete_object() vs rename
vfs: don't call ima_file_check() unconditionally in nfsd_open()
fs: inode - remove 8 bytes of padding on 64bits allowing 1 more objects/slab under slub
Switch proc/self to nd_set_link()
fix LOOKUP_FOLLOW on automount "symlinks"
This fixes the filepath encoded in <linux/amba/bus.h> and adds
some documentation as to what this bus really means.
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This removes 8 bytes of padding from struct inode on 64bit builds, and
so allows 1 more object/slab in the inode_cache when using slub.
Signed-off-by: Richard Kennedy <richard@rsk.demon.co.uk>
----
patch against 2.6.33-rc8
compiled & tested on x86_64 AMDX2
I've been running this patch for over a week with no obvious problems
regards
Richard
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Most laptops have keys that are intended to toggle all device state, not
just wifi. These are currently generally mapped to KEY_WLAN. As a result,
rfkill will only kill or enable wifi in response to the key press. This
confuses users and can make it difficult for them to enable bluetooth
and wwan devices.
This patch adds a new keycode, KEY_RFKILL. It indicates that the system
should toggle the state of all rfkillable devices.
Signed-off-by: Matthew Garrett <mjg@redhat.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
This patch fixes following sparse warnings:
include/linux/kfifo.h:127:25: warning: Using plain integer as NULL pointer
kernel/kfifo.c:83:21: warning: Using plain integer as NULL pointer
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Acked-by: Stefani Seibold <stefani@seibold.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
perf top: Fix help text alignment
perf: Fix hypervisor sample reporting
perf: Make bp_len type to u64 generic across the arch
The "Untangling ima mess, part 2 with counters" patch messed
up the counters. Based on conversations with Al Viro, this patch
streamlines ima_path_check() by removing the counter maintaince.
The counters are now updated independently, from measuring the file,
in __dentry_open() and alloc_file() by calling ima_counts_get().
ima_path_check() is called from nfsd and do_filp_open().
It also did not measure all files that should have been measured.
Reason: ima_path_check() got bogus value passed as mask.
[AV: mea culpa]
[AV: add missing nfsd bits]
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev:
[libata] Call flush_dcache_page after PIO data transfers in libata-sff.c
ahci: add Acer G725 to broken suspend list
libata: fix ata_id_logical_per_physical_sectors
libata-scsi passthru: fix bug which truncated LBA48 return values
This is to make the annotation of percpu variables during the next merge
window less painfull.
Extracted from a patch by Rusty Russell.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
futex: Handle futex value corruption gracefully
futex: Handle user space corruption gracefully
futex_lock_pi() key refcnt fix
softlockup: Add sched_clock_tick() to avoid kernel warning on kgdb resume
The value we get from the low byte of the ATA_ID_SECTOR_SIZE word is not not
a plain multiple, but the log of it, so fix the helper to give the correct
answer. Without this we'll get an incorrect minimal I/O size in the block
limits VPD page for 4k sector drives.
Also change the return value of ata_id_logical_per_physical_sectors to u16
for the unlikely case of very large logical sectors.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (23 commits)
connector: Delete buggy notification code.
be2net: use eq-id to calculate cev-isr reg offset
Bluetooth: Use the control channel for raw HID reports
Bluetooth: Add DFU driver for Atheros Bluetooth chipset AR3011
Bluetooth: Redo checks in IRQ handler for shared IRQ support
Bluetooth: Fix memory leak in L2CAP
Bluetooth: Remove double free of SKB pointer in L2CAP
cdc_ether: Partially revert "usbnet: Set link down initially ..."
be2net: Fix memset() arg ordering.
bonding: bond_open error return value
ixgbe: if ixgbe_copy_dcb_cfg is going to fail learn about it early
ixgbe: set the correct DCB bit for pg tx settings
igbvf: fix issue w/ mapped_as_page being left set after unmap
drivers/net: ks8851_mll ethernet network driver
be2net: Bug fix to support newer generation of BE ASIC
starfire: clean up properly if firmware loading fails
mac80211: fix NULL pointer dereference when ftrace is enabled
netfilter: ctnetlink: fix expectation mask dump
ipv6: conntrack: Add member of user to nf_ct_frag6_queue structure
ath9k: fix eeprom INI values override for 2GHz-only cards
...
