This patch is a continuation of efforts trying to optimize find_vma(),
avoiding potentially expensive rbtree walks to locate a vma upon faults.
The original approach (https://lkml.org/lkml/2013/11/1/410), where the
largest vma was also cached, ended up being too specific and random,
thus further comparison with other approaches were needed. There are
two things to consider when dealing with this, the cache hit rate and
the latency of find_vma(). Improving the hit-rate does not necessarily
translate in finding the vma any faster, as the overhead of any fancy
caching schemes can be too high to consider.
We currently cache the last used vma for the whole address space, which
provides a nice optimization, reducing the total cycles in find_vma() by
up to 250%, for workloads with good locality. On the other hand, this
simple scheme is pretty much useless for workloads with poor locality.
Analyzing ebizzy runs shows that, no matter how many threads are
running, the mmap_cache hit rate is less than 2%, and in many situations
below 1%.
The proposed approach is to replace this scheme with a small per-thread
cache, maximizing hit rates at a very low maintenance cost.
Invalidations are performed by simply bumping up a 32-bit sequence
number. The only expensive operation is in the rare case of a seq
number overflow, where all caches that share the same address space are
flushed. Upon a miss, the proposed replacement policy is based on the
page number that contains the virtual address in question. Concretely,
the following results are seen on an 80 core, 8 socket x86-64 box:
1) System bootup: Most programs are single threaded, so the per-thread
scheme does improve ~50% hit rate by just adding a few more slots to
the cache.
+----------------+----------+------------------+
| caching scheme | hit-rate | cycles (billion) |
+----------------+----------+------------------+
| baseline | 50.61% | 19.90 |
| patched | 73.45% | 13.58 |
+----------------+----------+------------------+
2) Kernel build: This one is already pretty good with the current
approach as we're dealing with good locality.
+----------------+----------+------------------+
| caching scheme | hit-rate | cycles (billion) |
+----------------+----------+------------------+
| baseline | 75.28% | 11.03 |
| patched | 88.09% | 9.31 |
+----------------+----------+------------------+
3) Oracle 11g Data Mining (4k pages): Similar to the kernel build workload.
+----------------+----------+------------------+
| caching scheme | hit-rate | cycles (billion) |
+----------------+----------+------------------+
| baseline | 70.66% | 17.14 |
| patched | 91.15% | 12.57 |
+----------------+----------+------------------+
4) Ebizzy: There's a fair amount of variation from run to run, but this
approach always shows nearly perfect hit rates, while baseline is just
about non-existent. The amounts of cycles can fluctuate between
anywhere from ~60 to ~116 for the baseline scheme, but this approach
reduces it considerably. For instance, with 80 threads:
+----------------+----------+------------------+
| caching scheme | hit-rate | cycles (billion) |
+----------------+----------+------------------+
| baseline | 1.06% | 91.54 |
| patched | 99.97% | 14.18 |
+----------------+----------+------------------+
[akpm@linux-foundation.org: fix nommu build, per Davidlohr]
[akpm@linux-foundation.org: document vmacache_valid() logic]
[akpm@linux-foundation.org: attempt to untangle header files]
[akpm@linux-foundation.org: add vmacache_find() BUG_ON]
[hughd@google.com: add vmacache_valid_mm() (from Oleg)]
[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: adjust and enhance comments]
Signed-off-by: Davidlohr Bueso <davidlohr@hp.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Michel Lespinasse <walken@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Tested-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Merge commit 'v3.10.73' into msm-3.10
This merge brings us up to date with upstream kernel.org tag v3.10.73.
As part of the conflict resolution, changes introduced by commit 72684eae7
("arm64: Fix up /proc/cpuinfo") have been intentionally dropped, as they
conflict with Android changes msm-3.10 kernel to solve the problems
in a different way. Since userspace readers of this file may depend on
the existing msm-3.10 implementation, it's left as-is for now. The
commit may later be introduced if it is found to not impact userspaces
paired with this kernel.
* commit 'v3.10.73' (264 commits):
Linux 3.10.73
target: Allow Write Exclusive non-reservation holders to READ
target: Allow AllRegistrants to re-RESERVE existing reservation
target: Fix R_HOLDER bit usage for AllRegistrants
target/pscsi: Fix NULL pointer dereference in get_device_type
iscsi-target: Avoid early conn_logout_comp for iser connections
target: Fix reference leak in target_get_sess_cmd() error path
ARM: at91: pm: fix at91rm9200 standby
ipvs: rerouting to local clients is not needed anymore
ipvs: add missing ip_vs_pe_put in sync code
powerpc/smp: Wait until secondaries are active & online
x86/vdso: Fix the build on GCC5
x86/fpu: Drop_fpu() should not assume that tsk equals current
x86/fpu: Avoid math_state_restore() without used_math() in __restore_xstate_sig()
crypto: aesni - fix memory usage in GCM decryption
libsas: Fix Kernel Crash in smp_execute_task
xen-pciback: limit guest control of command register
nilfs2: fix deadlock of segment constructor during recovery
regulator: core: Fix enable GPIO reference counting
regulator: Only enable disabled regulators on resume
ALSA: hda - Treat stereo-to-mono mix properly
ALSA: hda - Add workaround for MacBook Air 5,2 built-in mic
ALSA: hda - Set single_adc_amp flag for CS420x codecs
ALSA: hda - Don't access stereo amps for mono channel widgets
ALSA: hda - Fix built-in mic on Compaq Presario CQ60
ALSA: control: Add sanity checks for user ctl id name string
spi: pl022: Fix race in giveback() leading to driver lock-up
tpm/ibmvtpm: Additional LE support for tpm_ibmvtpm_send
workqueue: fix hang involving racing cancel[_delayed]_work_sync()'s for PREEMPT_NONE
can: add missing initialisations in CAN related skbuffs
Change email address for 8250_pci
virtio_console: init work unconditionally
fuse: notify: don't move pages
fuse: set stolen page uptodate
drm/radeon: drop setting UPLL to sleep mode
drm/radeon: do a posting read in rs600_set_irq
drm/radeon: do a posting read in si_set_irq
drm/radeon: do a posting read in r600_set_irq
drm/radeon: do a posting read in r100_set_irq
drm/radeon: do a posting read in evergreen_set_irq
drm/radeon: fix DRM_IOCTL_RADEON_CS oops
tcp: make connect() mem charging friendly
net: compat: Update get_compat_msghdr() to match copy_msghdr_from_user() behaviour
tcp: fix tcp fin memory accounting
Revert "net: cx82310_eth: use common match macro"
rxrpc: bogus MSG_PEEK test in rxrpc_recvmsg()
caif: fix MSG_OOB test in caif_seqpkt_recvmsg()
inet_diag: fix possible overflow in inet_diag_dump_one_icsk()
rds: avoid potential stack overflow
net: sysctl_net_core: check SNDBUF and RCVBUF for min length
sparc64: Fix several bugs in memmove().
sparc: Touch NMI watchdog when walking cpus and calling printk
sparc: perf: Make counting mode actually work
sparc: perf: Remove redundant perf_pmu_{en|dis}able calls
sparc: semtimedop() unreachable due to comparison error
sparc32: destroy_context() and switch_mm() needs to disable interrupts.
Linux 3.10.72
ath5k: fix spontaneus AR5312 freezes
ACPI / video: Load the module even if ACPI is disabled
drm/radeon: fix 1 RB harvest config setup for TN/RL
Drivers: hv: vmbus: incorrect device name is printed when child device is unregistered
HID: fixup the conflicting keyboard mappings quirk
HID: input: fix confusion on conflicting mappings
staging: comedi: cb_pcidas64: fix incorrect AI range code handling
dm snapshot: fix a possible invalid memory access on unload
dm: fix a race condition in dm_get_md
dm io: reject unsupported DISCARD requests with EOPNOTSUPP
dm mirror: do not degrade the mirror on discard error
staging: comedi: comedi_compat32.c: fix COMEDI_CMD copy back
clk: sunxi: Support factor clocks with N factor starting not from 0
fixed invalid assignment of 64bit mask to host dma_boundary for scatter gather segment boundary limit.
nilfs2: fix potential memory overrun on inode
IB/qib: Do not write EEPROM
sg: fix read() error reporting
ALSA: hda - Add pin configs for ASUS mobo with IDT 92HD73XX codec
ALSA: pcm: Don't leave PREPARED state after draining
tty: fix up atime/mtime mess, take four
sunrpc: fix braino in ->poll()
procfs: fix race between symlink removals and traversals
debugfs: leave freeing a symlink body until inode eviction
autofs4 copy_dev_ioctl(): keep the value of ->size we'd used for allocation
USB: serial: fix potential use-after-free after failed probe
TTY: fix tty_wait_until_sent on 64-bit machines
USB: serial: fix infinite wait_until_sent timeout
net: irda: fix wait_until_sent poll timeout
xhci: fix reporting of 0-sized URBs in control endpoint
xhci: Allocate correct amount of scratchpad buffers
usb: ftdi_sio: Add jtag quirk support for Cyber Cortex AV boards
USB: usbfs: don't leak kernel data in siginfo
USB: serial: cp210x: Adding Seletek device id's
KVM: MIPS: Fix trace event to save PC directly
KVM: emulate: fix CMPXCHG8B on 32-bit hosts
Btrfs:__add_inode_ref: out of bounds memory read when looking for extended ref.
Btrfs: fix data loss in the fast fsync path
btrfs: fix lost return value due to variable shadowing
iio: imu: adis16400: Fix sign extension
x86/asm/entry/64: Remove a bogus 'ret_from_fork' optimization
PM / QoS: remove duplicate call to pm_qos_update_target
target: Check for LBA + sectors wrap-around in sbc_parse_cdb
mm/memory.c: actually remap enough memory
mm/compaction: fix wrong order check in compact_finished()
mm/nommu.c: fix arithmetic overflow in __vm_enough_memory()
mm/mmap.c: fix arithmetic overflow in __vm_enough_memory()
mm/hugetlb: add migration entry check in __unmap_hugepage_range
team: don't traverse port list using rcu in team_set_mac_address
udp: only allow UFO for packets from SOCK_DGRAM sockets
usb: plusb: Add support for National Instruments host-to-host cable
macvtap: make sure neighbour code can push ethernet header
net: compat: Ignore MSG_CMSG_COMPAT in compat_sys_{send, recv}msg
team: fix possible null pointer dereference in team_handle_frame
net: reject creation of netdev names with colons
ematch: Fix auto-loading of ematch modules.
net: phy: Fix verification of EEE support in phy_init_eee
ipv4: ip_check_defrag should not assume that skb_network_offset is zero
ipv4: ip_check_defrag should correctly check return value of skb_copy_bits
gen_stats.c: Duplicate xstats buffer for later use
rtnetlink: call ->dellink on failure when ->newlink exists
ipv6: fix ipv6_cow_metrics for non DST_HOST case
rtnetlink: ifla_vf_policy: fix misuses of NLA_BINARY
Linux 3.10.71
libceph: fix double __remove_osd() problem
libceph: change from BUG to WARN for __remove_osd() asserts
libceph: assert both regular and lingering lists in __remove_osd()
MIPS: Export FP functions used by lose_fpu(1) for KVM
x86, mm/ASLR: Fix stack randomization on 64-bit systems
blk-throttle: check stats_cpu before reading it from sysfs
jffs2: fix handling of corrupted summary length
md/raid1: fix read balance when a drive is write-mostly.
md/raid5: Fix livelock when array is both resyncing and degraded.
metag: Fix KSTK_EIP() and KSTK_ESP() macros
gpio: tps65912: fix wrong container_of arguments
arm64: compat Fix siginfo_t -> compat_siginfo_t conversion on big endian
hx4700: regulator: declare full constraints
KVM: x86: update masterclock values on TSC writes
KVM: MIPS: Don't leak FPU/DSP to guest
ARC: fix page address calculation if PAGE_OFFSET != LINUX_LINK_BASE
ntp: Fixup adjtimex freq validation on 32-bit systems
kdb: fix incorrect counts in KDB summary command output
ARM: pxa: add regulator_has_full_constraints to poodle board file
ARM: pxa: add regulator_has_full_constraints to corgi board file
vt: provide notifications on selection changes
usb: core: buffer: smallest buffer should start at ARCH_DMA_MINALIGN
USB: fix use-after-free bug in usb_hcd_unlink_urb()
USB: cp210x: add ID for RUGGEDCOM USB Serial Console
tty: Prevent untrappable signals from malicious program
axonram: Fix bug in direct_access
cfq-iosched: fix incorrect filing of rt async cfqq
cfq-iosched: handle failure of cfq group allocation
iscsi-target: Drop problematic active_ts_list usage
NFSv4.1: Fix a kfree() of uninitialised pointers in decode_cb_sequence_args
Added Little Endian support to vtpm module
tpm/tpm_i2c_stm_st33: Fix potential bug in tpm_stm_i2c_send
tpm: Fix NULL return in tpm_ibmvtpm_get_desired_dma
tpm_tis: verify interrupt during init
ARM: 8284/1: sa1100: clear RCSR_SMR on resume
tracing: Fix unmapping loop in tracing_mark_write
MIPS: KVM: Deliver guest interrupts after local_irq_disable()
nfs: don't call blocking operations while !TASK_RUNNING
mmc: sdhci-pxav3: fix setting of pdata->clk_delay_cycles
power_supply: 88pm860x: Fix leaked power supply on probe fail
ALSA: hdspm - Constrain periods to 2 on older cards
ALSA: off by one bug in snd_riptide_joystick_probe()
lmedm04: Fix usb_submit_urb BOGUS urb xfer, pipe 1 != type 3 in interrupt urb
cpufreq: speedstep-smi: enable interrupts when waiting
PCI: Fix infinite loop with ROM image of size 0
PCI: Generate uppercase hex for modalias var in uevent
HID: i2c-hid: Limit reads to wMaxInputLength bytes for input events
iwlwifi: mvm: always use mac color zero
iwlwifi: mvm: fix failure path when power_update fails in add_interface
iwlwifi: mvm: validate tid and sta_id in ba_notif
iwlwifi: pcie: disable the SCD_BASE_ADDR when we resume from WoWLAN
fsnotify: fix handling of renames in audit
xfs: set superblock buffer type correctly
xfs: inode unlink does not set AGI buffer type
xfs: ensure buffer types are set correctly
Bluetooth: ath3k: workaround the compatibility issue with xHCI controller
Linux 3.10.70
rbd: drop an unsafe assertion
media/rc: Send sync space information on the lirc device
net: sctp: fix passing wrong parameter header to param_type2af in sctp_process_param
ppp: deflate: never return len larger than output buffer
ipv4: tcp: get rid of ugly unicast_sock
tcp: ipv4: initialize unicast_sock sk_pacing_rate
bridge: dont send notification when skb->len == 0 in rtnl_bridge_notify
ipv6: replacing a rt6_info needs to purge possible propagated rt6_infos too
ping: Fix race in free in receive path
udp_diag: Fix socket skipping within chain
ipv4: try to cache dst_entries which would cause a redirect
net: sctp: fix slab corruption from use after free on INIT collisions
netxen: fix netxen_nic_poll() logic
ipv6: stop sending PTB packets for MTU < 1280
net: rps: fix cpu unplug
ip: zero sockaddr returned on error queue
Linux 3.10.69
crypto: crc32c - add missing crypto module alias
x86,kvm,vmx: Preserve CR4 across VM entry
kvm: vmx: handle invvpid vm exit gracefully
smpboot: Add missing get_online_cpus() in smpboot_register_percpu_thread()
ALSA: ak411x: Fix stall in work callback
ASoC: sgtl5000: add delay before first I2C access
ASoC: atmel_ssc_dai: fix start event for I2S mode
lib/checksum.c: fix build for generic csum_tcpudp_nofold
ext4: prevent bugon on race between write/fcntl
arm64: Fix up /proc/cpuinfo
nilfs2: fix deadlock of segment constructor over I_SYNC flag
lib/checksum.c: fix carry in csum_tcpudp_nofold
mm: pagewalk: call pte_hole() for VM_PFNMAP during walk_page_range
MIPS: Fix kernel lockup or crash after CPU offline/online
MIPS: IRQ: Fix disable_irq on CPU IRQs
PCI: Add NEC variants to Stratus ftServer PCIe DMI check
gpio: sysfs: fix memory leak in gpiod_sysfs_set_active_low
gpio: sysfs: fix memory leak in gpiod_export_link
Linux 3.10.68
target: Drop arbitrary maximum I/O size limit
iser-target: Fix implicit termination of connections
iser-target: Handle ADDR_CHANGE event for listener cm_id
iser-target: Fix connected_handler + teardown flow race
iser-target: Parallelize CM connection establishment
iser-target: Fix flush + disconnect completion handling
iscsi,iser-target: Initiate termination only once
vhost-scsi: Add missing virtio-scsi -> TCM attribute conversion
tcm_loop: Fix wrong I_T nexus association
vhost-scsi: Take configfs group dependency during VHOST_SCSI_SET_ENDPOINT
ib_isert: Add max_send_sge=2 minimum for control PDU responses
IB/isert: Adjust CQ size to HW limits
workqueue: fix subtle pool management issue which can stall whole worker_pool
gpio: squelch a compiler warning
efi-pstore: Make efi-pstore return a unique id
pstore/ram: avoid atomic accesses for ioremapped regions
pstore: Fix NULL pointer fault if get NULL prz in ramoops_get_next_prz
pstore: skip zero size persistent ram buffer in traverse
pstore: clarify clearing of _read_cnt in ramoops_context
pstore: d_alloc_name() doesn't return an ERR_PTR
pstore: Fail to unlink if a driver has not defined pstore_erase
ARM: 8109/1: mm: Modify pte_write and pmd_write logic for LPAE
ARM: 8108/1: mm: Introduce {pte,pmd}_isset and {pte,pmd}_isclear
ARM: DMA: ensure that old section mappings are flushed from the TLB
ARM: 7931/1: Correct virt_addr_valid
ARM: fix asm/memory.h build error
ARM: 7867/1: include: asm: use 'int' instead of 'unsigned long' for 'oldval' in atomic_cmpxchg().
ARM: 7866/1: include: asm: use 'long long' instead of 'u64' within atomic.h
ARM: lpae: fix definition of PTE_HWTABLE_PTRS
ARM: fix type of PHYS_PFN_OFFSET to unsigned long
ARM: LPAE: use phys_addr_t in alloc_init_pud()
ARM: LPAE: use signed arithmetic for mask definitions
ARM: mm: correct pte_same behaviour for LPAE.
ARM: 7829/1: Add ".text.unlikely" and ".text.hot" to arm unwind tables
drivers: net: cpsw: discard dual emac default vlan configuration
regulator: core: fix race condition in regulator_put()
spi/pxa2xx: Clear cur_chip pointer before starting next message
dm cache: fix missing ERR_PTR returns and handling
dm thin: don't allow messages to be sent to a pool target in READ_ONLY or FAIL mode
nl80211: fix per-station group key get/del and memory leak
NFSv4.1: Fix an Oops in nfs41_walk_client_list
nfs: fix dio deadlock when O_DIRECT flag is flipped
Input: i8042 - add noloop quirk for Medion Akoya E7225 (MD98857)
ALSA: seq-dummy: remove deadlock-causing events on close
powerpc/xmon: Fix another endiannes issue in RTAS call from xmon
can: kvaser_usb: Fix state handling upon BUS_ERROR events
can: kvaser_usb: Retry the first bulk transfer on -ETIMEDOUT
can: kvaser_usb: Send correct context to URB completion
can: kvaser_usb: Do not sleep in atomic context
ASoC: wm8960: Fix capture sample rate from 11250 to 11025
spi: dw-mid: fix FIFO size
Signed-off-by: Ian Maund <imaund@codeaurora.org>
commit 146755923262037fc4c54abc28c04b1103f3cc51 upstream.
The output of KDB 'summary' command should report MemTotal, MemFree
and Buffers output in kB. Current codes report in unit of pages.
A define of K(x) as
is defined in the code, but not used.
This patch would apply the define to convert the values to kB.
Please include me on Cc on replies. I do not subscribe to linux-kernel.
Signed-off-by: Jay Lan <jlan@sgi.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
On non-developer devices kgdb prevents CONFIG_PANIC_TIMEOUT from
rebooting the device after a panic. Add module parameters
debug_core.break_on_exception and debug_core.break_on_panic to
allow skipping debug on panics and exceptions respectively. Both
default to true to preserve existing behavior.
Change-Id: I75dce7263e96cee069a9750920cce83dc6f98e8c
Signed-off-by: Colin Cross <ccross@android.com>
kdb expects carriage returns through the serial port to terminate
commands. Modify it to accept the first seen carriage return or
new line as a terminator, but not treat \r\n as two terminators.
Change-Id: I06166017e7703d24310eefcb71c3a7d427088db7
Signed-off-by: Colin Cross <ccross@android.com>
Currently help message of /proc/sysrq-trigger highlight its upper-case
characters, like below:
SysRq : HELP : loglevel(0-9) reBoot Crash terminate-all-tasks(E)
memory-full-oom-kill(F) kill-all-tasks(I) ...
this would confuse user trigger sysrq by upper-case character, which is
inconsistent with the real lower-case character registed key.
This inconsistent help message will also lead more confused when
26 upper-case letters put into use in future.
This patch fix kgdb sysrq key: "debug(g)"
Signed-off-by: zhangwei(Jovi) <jovi.zhangwei@huawei.com>
Cc: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cleanups
Remove kdb ssb command - there is no in kernel disassembler to support it
Remove kdb ll command - Always caused a kernel oops and there were no
bug reports so no one was using this command
Use kernel ARRAY_SIZE macro instead of array computations
Fixes
Stop oops in kdb if user executes kdb_defcmd with args
kdb help command truncated text
ppc64 support for kgdbts
Add missing kconfig option from original kdb port for dealing with
catastrophic kernel crashes such that you can reboot automatically
on continue from kdb
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Merge tag 'for_linux-3.9' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/kgdb
Pull KGDB/KDB fixes and cleanups from Jason Wessel:
"For a change we removed more code than we added. If people aren't
using it we shouldn't be carrying it. :-)
Cleanups:
- Remove kdb ssb command - there is no in kernel disassembler to
support it
- Remove kdb ll command - Always caused a kernel oops and there were
no bug reports so no one was using this command
- Use kernel ARRAY_SIZE macro instead of array computations
Fixes:
- Stop oops in kdb if user executes kdb_defcmd with args
- kdb help command truncated text
- ppc64 support for kgdbts
- Add missing kconfig option from original kdb port for dealing with
catastrophic kernel crashes such that you can reboot automatically
on continue from kdb"
* tag 'for_linux-3.9' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/kgdb:
kdb: Remove unhandled ssb command
kdb: Prevent kernel oops with kdb_defcmd
kdb: Remove the ll command
kdb_main: fix help print
kdb: Fix overlap in buffers with strcpy
Fixed dead ifdef block by adding missing Kconfig option.
kdb: Setup basic kdb state before invoking commands via kgdb
kdb: use ARRAY_SIZE where possible
kgdb/kgdbts: support ppc64
kdb: A fix for kdb command table expansion
The 'ssb' command can only be handled when we have a disassembler, to check for
branches, so remove the 'ssb' command for now.
Signed-off-by: Vincent Stehlé <vincent.stehle@laposte.net>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
The kdb_defcmd can only be used to display the available command aliases
while using the kernel debug shell. If you try to define a new macro
while the kernel debugger is active it will oops. The debug shell
macros must use pre-allocated memory set aside at the time kdb_init()
is run, and the kdb_defcmd is restricted to only working at the time
that the kdb_init sequence is being run, which only occurs if you
actually activate the kernel debugger.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Recently some code inspection was done after fixing a problem with
kmalloc used while in the kernel debugger context (which is not
legal), and it turned up the fact that kdb ll command will oops the
kernel.
Given that there have been zero bug reports on the command combined
with the fact it will oops the kernel it is clearly not being used.
Instead of fixing it, it will be removed.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
The help command was chopping all the usage instructions such that
they were not readable.
Example:
bta [D|R|S|T|C|Z|E|U|I| Backtrace all processes matching state flag
per_cpu <sym> [<bytes>] [<c Display per_cpu variables
Where as it should look like:
bta [D|R|S|T|C|Z|E|U|I|M|A]
Backtrace all processes matching state flag
per_cpu <sym> [<bytes>] [<cpu>]
Display per_cpu variables
All that is needed is to check the how long the cmd_usage is and jump
to the next line when appropriate.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Maxime reported that strcpy(s->usage, s->usage+1) has no definitive
guarantee that it will work on all archs the same way when you have
overlapping memory. The fix is simple for the kdb code because we
still have the original string memory in the function scope, so we
just have to use that as the argument instead.
Reported-by: Maxime Villard <rustyBSD@gmx.fr>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Although invasive kdb commands are not supported via kgdb, some useful
non-invasive commands like bt* require basic kdb state to be setup before
calling into the kdb code. Factor out some of this code and call it before
and after executing kdb commands via kgdb.
Signed-off-by: Matt Klein <mklein@twitter.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
When locally adding in some additional kdb commands, I stumbled
across an issue with the dynamic expansion of the kdb command table.
When the number of kdb commands exceeds the size of the statically
allocated kdb_base_commands[] array, additional space is allocated in
the kdb_register_repeat() routine.
The unused portion of the newly allocated array was not being initialized
to zero properly and this would result in segfaults when help '?' was
executed or when a search for a non-existing command would traverse the
command table beyond the end of valid command entries and then attempt
to use the non-zeroed area as actual command entries.
Signed-off-by: John Blackwood <john.blackwood@ccur.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
There's no reason kgdb.h itself needs to include the 8250 serial port
header file. So push it down to the _very_ limited number of individual
drivers that need the values in that file, and fix up the places where
people really wanted serial_core.h and platform_device.h.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
You should never look at such a module, so it's excised from all paths
which traverse the modules list.
We add the state at the end, to avoid gratuitous ABI break (ksplice).
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cleanups
Clean up compile warnings in kgdboc.c and x86/kernel/kgdb.c
Add module event hooks for simplified debugging with gdb
Fixes
Fix kdb to stop paging with 'q' on bta and dmesg
Fix for data that scrolls off the vga console due to line wrapping
when using the kdb pager
New
The debug core registers for kernel module events which allows a
kernel aware gdb to automatically load symbols and break on entry
to a kernel module
Allow kgdboc=kdb to setup kdb on the vga console
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Merge tag 'for_linus-3.7' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/kgdb
Pull KGDB/KDB fixes and cleanups from Jason Wessel:
"Cleanups
- Clean up compile warnings in kgdboc.c and x86/kernel/kgdb.c
- Add module event hooks for simplified debugging with gdb
Fixes
- Fix kdb to stop paging with 'q' on bta and dmesg
- Fix for data that scrolls off the vga console due to line wrapping
when using the kdb pager
New
- The debug core registers for kernel module events which allows a
kernel aware gdb to automatically load symbols and break on entry
to a kernel module
- Allow kgdboc=kdb to setup kdb on the vga console"
* tag 'for_linus-3.7' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/kgdb:
tty/console: fix warnings in drivers/tty/serial/kgdboc.c
kdb,vt_console: Fix missed data due to pager overruns
kdb: Fix dmesg/bta scroll to quit with 'q'
kgdboc: Accept either kbd or kdb to activate the vga + keyboard kdb shell
kgdb,x86: fix warning about unused variable
mips,kgdb: fix recursive page fault with CONFIG_KPROBES
kgdb: Add module event hooks
It is possible to miss data when using the kdb pager. The kdb pager
does not pay attention to the maximum column constraint of the screen
or serial terminal. This result is not incrementing the shown lines
correctly and the pager will print more lines that fit on the screen.
Obviously that is less than useful when using a VGA console where you
cannot scroll back.
The pager will now look at the kdb_buffer string to see how many
characters are printed. It might not be perfect considering you can
output ASCII that might move the cursor position, but it is a
substantially better approximation for viewing dmesg and trace logs.
This also means that the vt screen needs to set the kdb COLUMNS
variable.
Cc: <stable@vger.kernel.org>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
If you press 'q' the pager should exit instead of printing everything
from dmesg which can really bog down a 9600 baud serial link.
The same is true for the bta command.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Allow gdb to auto load kernel modules when it is attached,
which makes it trivially easy to debug module init functions
or pre-set breakpoints in a kernel module that has not loaded yet.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
This command disables NMI-entry. If NMI source has been previously shared
with a serial console ("debug port"), this effectively releases the port
from KDB exclusive use, and makes the console available for normal use.
Of course, NMI can be reenabled, enable_nmi modparam is used for that:
echo 1 > /sys/module/kdb/parameters/enable_nmi
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Acked-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The new arch callback should manage NMIs that usually cause KGDB to
enter. That is, not all NMIs should be enabled/disabled, but only
those that issue kgdb_handle_exception().
We must mask it as serial-line interrupt can be used as an NMI, so
if the original KGDB-entry cause was say a breakpoint, then every
input to KDB console will cause KGDB to reenter, which we don't want.
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Acked-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently kernel never set KGDB_REASON_NMI. We do now, when we enter
KGDB/KDB from an NMI.
This is not to be confused with kgdb_nmicallback(), NMI callback is
an entry for the slave CPUs during CPUs roundup, but REASON_NMI is the
entry for the master CPU.
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Having the CPU in the more prompt is completely redundent vs the
standard kdb prompt, and it also wastes 32 bytes on the stack.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
This code cleanup was missed in the original kdb merge, and this code
is simply not used at all. The code that was previously used to set
the KDB_FLAG_ONLY_DO_DUMP was removed prior to the initial kdb merge.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
The locked variants are prone to deadlocks (suppose we got to the
debugger w/ the logbuf lock held), so let's switch to nolock variants.
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The function is no longer needed, so remove it.
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The kgdb dmesg command is broken after the printk rework. The old logic
in kdb code makes no sense in terms of current printk/logging storage
format, and KDB simply hangs forever.
This patch revives the command by switching to kmsg_dumper iterator.
The code is now much more simpler and shorter.
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
3.4: Fix an an Smatch warning that appeared in the 3.4 merge window
3.0: Fix kgdb test suite with SMP for all archs without HW single stepping
2.6.36: Fix kgdb sw breakpoints with CONFIG_DEBUG_RODATA=y limitations on x86
2.6.26: Fix oops on kgdb test suite with CONFIG_DEBUG_RODATA
Fix kgdb test suite with SMP for all archs with HW single stepping
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Merge tag 'for_linus-3.4-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/kgdb
Pull KGDB/KDB regression fixes from Jason Wessel:
- Fix a Smatch warning that appeared in the 3.4 merge window
- Fix kgdb test suite with SMP for all archs without HW single stepping
- Fix kgdb sw breakpoints with CONFIG_DEBUG_RODATA=y limitations on x86
- Fix oops on kgdb test suite with CONFIG_DEBUG_RODATA
- Fix kgdb test suite with SMP for all archs with HW single stepping
* tag 'for_linus-3.4-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/kgdb:
x86,kgdb: Fix DEBUG_RODATA limitation using text_poke()
kgdb,debug_core: pass the breakpoint struct instead of address and memory
kgdbts: (2 of 2) fix single step awareness to work correctly with SMP
kgdbts: (1 of 2) fix single step awareness to work correctly with SMP
kgdbts: Fix kernel oops with CONFIG_DEBUG_RODATA
kdb: Fix smatch warning on dbg_io_ops->is_console
There is extra state information that needs to be exposed in the
kgdb_bpt structure for tracking how a breakpoint was installed. The
debug_core only uses the the probe_kernel_write() to install
breakpoints, but this is not enough for all the archs. Some arch such
as x86 need to use text_poke() in order to install a breakpoint into a
read only page.
Passing the kgdb_bpt structure to kgdb_arch_set_breakpoint() and
kgdb_arch_remove_breakpoint() allows other archs to set the type
variable which indicates how the breakpoint was installed.
Cc: stable@vger.kernel.org # >= 2.6.36
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
The Smatch tool warned that the change from commit b8adde8dd
(kdb: Avoid using dbg_io_ops until it is initialized) should
add another null check later in the kdb_printf().
It is worth noting that the second use of dbg_io_ops->is_console
is protected by the KDB_PAGER state variable which would only
get set when kdb is fully active and initialized. If we
ever encounter changes or defects in the KDB_PAGER state
we do not want to crash the kernel in a kdb_printf/printk.
CC: Tim Bird <tim.bird@am.sony.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
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Merge tag 'split-asm_system_h-for-linus-20120328' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-asm_system
Pull "Disintegrate and delete asm/system.h" from David Howells:
"Here are a bunch of patches to disintegrate asm/system.h into a set of
separate bits to relieve the problem of circular inclusion
dependencies.
I've built all the working defconfigs from all the arches that I can
and made sure that they don't break.
The reason for these patches is that I recently encountered a circular
dependency problem that came about when I produced some patches to
optimise get_order() by rewriting it to use ilog2().
This uses bitops - and on the SH arch asm/bitops.h drags in
asm-generic/get_order.h by a circuituous route involving asm/system.h.
The main difficulty seems to be asm/system.h. It holds a number of
low level bits with no/few dependencies that are commonly used (eg.
memory barriers) and a number of bits with more dependencies that
aren't used in many places (eg. switch_to()).
These patches break asm/system.h up into the following core pieces:
(1) asm/barrier.h
Move memory barriers here. This already done for MIPS and Alpha.
(2) asm/switch_to.h
Move switch_to() and related stuff here.
(3) asm/exec.h
Move arch_align_stack() here. Other process execution related bits
could perhaps go here from asm/processor.h.
(4) asm/cmpxchg.h
Move xchg() and cmpxchg() here as they're full word atomic ops and
frequently used by atomic_xchg() and atomic_cmpxchg().
(5) asm/bug.h
Move die() and related bits.
(6) asm/auxvec.h
Move AT_VECTOR_SIZE_ARCH here.
Other arch headers are created as needed on a per-arch basis."
Fixed up some conflicts from other header file cleanups and moving code
around that has happened in the meantime, so David's testing is somewhat
weakened by that. We'll find out anything that got broken and fix it..
* tag 'split-asm_system_h-for-linus-20120328' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-asm_system: (38 commits)
Delete all instances of asm/system.h
Remove all #inclusions of asm/system.h
Add #includes needed to permit the removal of asm/system.h
Move all declarations of free_initmem() to linux/mm.h
Disintegrate asm/system.h for OpenRISC
Split arch_align_stack() out from asm-generic/system.h
Split the switch_to() wrapper out of asm-generic/system.h
Move the asm-generic/system.h xchg() implementation to asm-generic/cmpxchg.h
Create asm-generic/barrier.h
Make asm-generic/cmpxchg.h #include asm-generic/cmpxchg-local.h
Disintegrate asm/system.h for Xtensa
Disintegrate asm/system.h for Unicore32 [based on ver #3, changed by gxt]
Disintegrate asm/system.h for Tile
Disintegrate asm/system.h for Sparc
Disintegrate asm/system.h for SH
Disintegrate asm/system.h for Score
Disintegrate asm/system.h for S390
Disintegrate asm/system.h for PowerPC
Disintegrate asm/system.h for PA-RISC
Disintegrate asm/system.h for MN10300
...
Remove all #inclusions of asm/system.h preparatory to splitting and killing
it. Performed with the following command:
perl -p -i -e 's!^#\s*include\s*<asm/system[.]h>.*\n!!' `grep -Irl '^#\s*include\s*<asm/system[.]h>' *`
Signed-off-by: David Howells <dhowells@redhat.com>
- Fix KDB keyboard repeat scan codes and leaked keyboard events
- Fix kernel crash with kdb_printf() for users who compile new kdb_printf()'s
in early code
- Return all segment registers to gdb on x86_64
Features:
- KDB/KGDB hook the reboot notifier and end user can control if it stops,
detaches or does nothing (updated docs as well)
- Notify users who use CONFIG_DEBUG_RODATA to use hw breakpoints
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Merge tag 'for_linus-3.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/kgdb
Pull KGDB/KDB updates from Jason Wessel:
"Fixes:
- Fix KDB keyboard repeat scan codes and leaked keyboard events
- Fix kernel crash with kdb_printf() for users who compile new
kdb_printf()'s in early code
- Return all segment registers to gdb on x86_64
Features:
- KDB/KGDB hook the reboot notifier and end user can control if it
stops, detaches or does nothing (updated docs as well)
- Notify users who use CONFIG_DEBUG_RODATA to use hw breakpoints"
* tag 'for_linus-3.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/kgdb:
kdb: Add message about CONFIG_DEBUG_RODATA on failure to install breakpoint
kdb: Avoid using dbg_io_ops until it is initialized
kgdb,debug_core: add the ability to control the reboot notifier
KDB: Fix usability issues relating to the 'enter' key.
kgdb,debug-core,gdbstub: Hook the reboot notifier for debugger detach
kgdb: Respect that flush op is optional
kgdb: x86: Return all segment registers also in 64-bit mode
On x86, if CONFIG_DEBUG_RODATA is set, one cannot set breakpoints
via KDB. Apparently this is a well-known problem, as at least one distribution
now ships with both KDB enabled and CONFIG_DEBUG_RODATA=y for security reasons.
This patch adds an printk message to the breakpoint failure case,
in order to provide suggestions about how to use the debugger.
Reported-by: Tim Bird <tim.bird@am.sony.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Acked-by: Tim Bird <tim.bird@am.sony.com>
This fixes a bug with setting a breakpoint during kdb initialization
(from kdb_cmds). Any call to kdb_printf() before the initialization
of the kgdboc serial console driver (which happens much later during
bootup than kdb_init), results in kernel panic due to the use of
dbg_io_ops before it is initialized.
Signed-off-by: Tim Bird <tim.bird@am.sony.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Sometimes it is desirable to stop the kernel debugger before allowing
a system to reboot either with kdb or kgdb. This patch adds the
ability to turn the reboot notifier on and off or enter the debugger
and stop kernel execution before rebooting.
It is possible to change the setting after booting the kernel with the
following:
echo 1 > /sys/module/debug_core/parameters/kgdbreboot
It is also possible to change this setting using kdb / kgdb to
manipulate the variable directly.
Using KDB:
mm kgdbreboot 1
Using gdb:
set kgdbreboot=1
Reported-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
This fixes the following problems:
1) Typematic-repeat of 'enter' gives warning message
and leaks make/break if KDB exits. Repeats
look something like 0x1c 0x1c .... 0x9c
2) Use of 'keypad enter' gives warning message and
leaks the ENTER break/make code out if KDB exits.
KP ENTER repeats look someting like 0xe0 0x1c
0xe0 0x1c ... 0xe0 0x9c.
3) Lag on the order of seconds between "break" and "make" when
expecting the enter "break" code. Seen under virtualized
environments such as VMware ESX.
The existing special enter handler tries to glob the enter break code,
but this fails if the other (KP) enter was used, or if there was a key
repeat. It also fails if you mashed some keys along with enter, and
you ended up with a non-enter make or non-enter break code coming
after the enter make code. So first, we modify the handler to handle
these cases. But performing these actions on every enter is annoying
since now you can't hold ENTER down to scroll <more>d messages in
KDB. Since this special behaviour is only necessary to handle the
exiting KDB ('g' + ENTER) without leaking scancodes to the OS. This
cleanup needs to get executed anytime the kdb_main loop exits.
Tested on QEMU. Set a bp on atkbd.c to verify no scan code was leaked.
Cc: Andrei Warkentin <andreiw@vmware.com>
[jason.wessel@windriver.com: move cleanup calls to kdb_main.c]
Signed-off-by: Andrei Warkentin <andrey.warkentin@gmail.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
The gdbstub and kdb should get detached if the system is rebooting.
Calling gdbstub_exit() will set the proper debug core state and send a
message to any debugger that is connected to correctly detach.
An attached debugger will receive the exit code from
include/linux/reboot.h based on SYS_HALT, SYS_REBOOT, etc...
Reported-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Not all kgdb I/O drivers implement a flush operation. Adjust
gdbstub_exit accordingly.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
module_ref contains two "unsigned int" fields.
Thats now too small, since some machines can open more than 2^32 files.
Check commit 518de9b39e (fs: allow for more than 2^31 files) for
reference.
We can add an aligned(2 * sizeof(unsigned long)) attribute to force
alloc_percpu() allocating module_ref areas in single cache lines.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Rusty Russell <rusty@rustcorp.com.au>
CC: Tejun Heo <tj@kernel.org>
CC: Robin Holt <holt@sgi.com>
CC: David Miller <davem@davemloft.net>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Change from direct comparison of ->pid with zero to is_idle_task().
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Jason Wessel <jason.wessel@windriver.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
* 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: (230 commits)
Revert "tracing: Include module.h in define_trace.h"
irq: don't put module.h into irq.h for tracking irqgen modules.
bluetooth: macroize two small inlines to avoid module.h
ip_vs.h: fix implicit use of module_get/module_put from module.h
nf_conntrack.h: fix up fallout from implicit moduleparam.h presence
include: replace linux/module.h with "struct module" wherever possible
include: convert various register fcns to macros to avoid include chaining
crypto.h: remove unused crypto_tfm_alg_modname() inline
uwb.h: fix implicit use of asm/page.h for PAGE_SIZE
pm_runtime.h: explicitly requires notifier.h
linux/dmaengine.h: fix implicit use of bitmap.h and asm/page.h
miscdevice.h: fix up implicit use of lists and types
stop_machine.h: fix implicit use of smp.h for smp_processor_id
of: fix implicit use of errno.h in include/linux/of.h
of_platform.h: delete needless include <linux/module.h>
acpi: remove module.h include from platform/aclinux.h
miscdevice.h: delete unnecessary inclusion of module.h
device_cgroup.h: delete needless include <linux/module.h>
net: sch_generic remove redundant use of <linux/module.h>
net: inet_timewait_sock doesnt need <linux/module.h>
...
Fix up trivial conflicts (other header files, and removal of the ab3550 mfd driver) in
- drivers/media/dvb/frontends/dibx000_common.c
- drivers/media/video/{mt9m111.c,ov6650.c}
- drivers/mfd/ab3550-core.c
- include/linux/dmaengine.h
There is no functional change.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>
Cc: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
These files were getting <linux/module.h> via an implicit non-obvious
path, but we want to crush those out of existence since they cost
time during compiles of processing thousands of lines of headers
for no reason. Give them the lightweight header that just contains
the EXPORT_SYMBOL infrastructure.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb:
kdb,kgdb: Allow arbitrary kgdb magic knock sequences
kdb: Remove all references to DOING_KGDB2
kdb,kgdb: Implement switch and pass buffer from kdb -> gdb
kdb: cleanup unused variables missed in the original kdb merge
The first packet that gdb sends when the kernel is in kdb mode seems
to change with every release of gdb. Instead of continuing to add
many different gdb packets, change kdb to automatically look for any
thing that looks like a gdb packet.
Example 1 cold start test:
echo g > /proc/sysrq-trigger
$D#44+
Example 2 cold start test:
echo g > /proc/sysrq-trigger
$3#33
The second one should re-enter kdb's shell right away and is purely a
test.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Davidlohr Bueso
Ian Maund
Jay Lan
Peter Zijlstra
Colin Cross
zhangwei(Jovi)
Linus Torvalds
Vincent
Jason Wessel
Matt Klein
Sasha Levin
John Blackwood
Greg Kroah-Hartman
Rusty Russell
Anton Vorontsov
David Howells
Tim Bird
Andrei Warkentin
Jan Kiszka
Cong Wang
Eric Dumazet
Paul E. McKenney
Andy Shevchenko
Paul Gortmaker