| Age | Commit message (Collapse) | Author | Files | Lines |
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vprintk_emit() prefix parsing should only be done for internal kernel
messages. This allows existing behavior to be kept in all cases.
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Kay Sievers <kay@vrfy.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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The current form of a KERN_<LEVEL> is "<.>".
Add printk_get_level and printk_skip_level functions to handle these
formats.
These functions centralize tests of KERN_<LEVEL> so a future modification
can change the KERN_<LEVEL> style and shorten the number of bytes consumed
by these headers.
[akpm@linux-foundation.org: fix build error and warning]
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Wu Fengguang <wfg@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Reported-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Kay Sievers <kay@vrfy.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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If argv_split() failed, the code will end up calling argv_free(NULL). Fix
it up and clean things up a bit.
Addresses Coverity report 703573.
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Serge Hallyn <serge.hallyn@canonical.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: WANG Cong <xiyou.wangcong@gmail.com>
Cc: Alan Cox <alan@linux.intel.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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On the suspend/resume path the boot CPU does not go though an
offline->online transition. This breaks the NMI detector post-resume
since it depends on PMU state that is lost when the system gets
suspended.
Fix this by forcing a CPU offline->online transition for the lockup
detector on the boot CPU during resume.
To provide more context, we enable NMI watchdog on Chrome OS. We have
seen several reports of systems freezing up completely which indicated
that the NMI watchdog was not firing for some reason.
Debugging further, we found a simple way of repro'ing system freezes --
issuing the command 'tasket 1 sh -c "echo nmilockup > /proc/breakme"'
after the system has been suspended/resumed one or more times.
With this patch in place, the system freeze result in panics, as
expected.
These panics provide a nice stack trace for us to debug the actual issue
causing the freeze.
[akpm@linux-foundation.org: fiddle with code comment]
[akpm@linux-foundation.org: make lockup_detector_bootcpu_resume() conditional on CONFIG_SUSPEND]
[akpm@linux-foundation.org: fix section errors]
Signed-off-by: Sameer Nanda <snanda@chromium.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Mandeep Singh Baines <msb@chromium.org>
Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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panic_lock is meant to ensure that panic processing takes place only on
one cpu; if any of the other cpus encounter a panic, they will spin
waiting to be shut down.
However, this causes a regression in this scenario:
1. Cpu 0 encounters a panic and acquires the panic_lock
and proceeds with the panic processing.
2. There is an interrupt on cpu 0 that also encounters
an error condition and invokes panic.
3. This second invocation fails to acquire the panic_lock
and enters the infinite while loop in panic_smp_self_stop.
Thus all panic processing is stopped, and the cpu is stuck for eternity
in the while(1) inside panic_smp_self_stop.
To address this, disable local interrupts with local_irq_disable before
acquiring the panic_lock. This will prevent interrupt handlers from
executing during the panic processing, thus avoiding this particular
problem.
Signed-off-by: Vikram Mulukutla <markivx@codeaurora.org>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Cc: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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When suid_dumpable=2, detect unsafe core_pattern settings and warn when
they are seen.
Signed-off-by: Kees Cook <keescook@chromium.org>
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alan Cox <alan@linux.intel.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Doug Ledford <dledford@redhat.com>
Cc: Serge Hallyn <serge.hallyn@canonical.com>
Cc: James Morris <james.l.morris@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Just setting the "error" to error number is enough on failure and It
doesn't require to set "error" variable to zero in each switch case,
since it was already initialized with zero. And also removed return 0
in switch case with break statement
Signed-off-by: Sasikantha babu <sasikanth.v19@gmail.com>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Serge E. Hallyn <serge@hallyn.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Recently, glibc made a change to suppress sign-conversion warnings in
FD_SET (glibc commit ceb9e56b3d1). This uncovered an issue with the
kernel's definition of __NFDBITS if applications #include
<linux/types.h> after including <sys/select.h>. A build failure would
be seen when passing the -Werror=sign-compare and -D_FORTIFY_SOURCE=2
flags to gcc.
It was suggested that the kernel should either match the glibc
definition of __NFDBITS or remove that entirely. The current in-kernel
uses of __NFDBITS can be replaced with BITS_PER_LONG, and there are no
uses of the related __FDELT and __FDMASK defines. Given that, we'll
continue the cleanup that was started with commit 8b3d1cda4f5f
("posix_types: Remove fd_set macros") and drop the remaining unused
macros.
Additionally, linux/time.h has similar macros defined that expand to
nothing so we'll remove those at the same time.
Reported-by: Jeff Law <law@redhat.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
CC: <stable@vger.kernel.org>
Signed-off-by: Josh Boyer <jwboyer@redhat.com>
[ .. and fix up whitespace as per akpm ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler changes from Ingo Molnar:
"The biggest change is a performance improvement on SMP systems:
| 4 socket 40 core + SMT Westmere box, single 30 sec tbench
| runs, higher is better:
|
| clients 1 2 4 8 16 32 64 128
|..........................................................................
| pre 30 41 118 645 3769 6214 12233 14312
| post 299 603 1211 2418 4697 6847 11606 14557
|
| A nice increase in performance.
which speedup is particularly noticeable on heavily interacting
few-tasks workloads, so the changes should help desktop-style Xorg
workloads and interactivity as well, on multi-core CPUs.
There are also cpuset suspend behavior fixes/restructuring and various
smaller tweaks."
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched: Fix race in task_group()
sched: Improve balance_cpu() to consider other cpus in its group as target of (pinned) task
sched: Reset loop counters if all tasks are pinned and we need to redo load balance
sched: Reorder 'struct lb_env' members to reduce its size
sched: Improve scalability via 'CPU buddies', which withstand random perturbations
cpusets: Remove/update outdated comments
cpusets, hotplug: Restructure functions that are invoked during hotplug
cpusets, hotplug: Implement cpuset tree traversal in a helper function
CPU hotplug, cpusets, suspend: Don't modify cpusets during suspend/resume
sched/x86: Remove broken power estimation
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git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core changes from Greg Kroah-Hartman:
"Here's the big driver core pull request for 3.6-rc1.
Unlike 3.5, this kernel should be a lot tamer, with the printk changes
now settled down. All we have here is some extcon driver updates, w1
driver updates, a few printk cleanups that weren't needed for 3.5, but
are good to have now, and some other minor fixes/changes in the driver
core.
All of these have been in the linux-next releases for a while now.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>"
* tag 'driver-core-3.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (38 commits)
printk: Export struct log size and member offsets through vmcoreinfo
Drivers: hv: Change the hex constant to a decimal constant
driver core: don't trigger uevent after failure
extcon: MAX77693: Add extcon-max77693 driver to support Maxim MAX77693 MUIC device
sysfs: fail dentry revalidation after namespace change fix
sysfs: fail dentry revalidation after namespace change
extcon: spelling of detach in function doc
extcon: arizona: Stop microphone detection if we give up on it
extcon: arizona: Update cable reporting calls and split headset
PM / Runtime: Do not increment device usage counts before probing
kmsg - do not flush partial lines when the console is busy
kmsg - export "continuation record" flag to /dev/kmsg
kmsg - avoid warning for CONFIG_PRINTK=n compilations
kmsg - properly print over-long continuation lines
driver-core: Use kobj_to_dev instead of re-implementing it
driver-core: Move kobj_to_dev from genhd.h to device.h
driver core: Move deferred devices to the end of dpm_list before probing
driver core: move uevent call to driver_register
driver core: fix shutdown races with probe/remove(v3)
Extcon: Arizona: Add driver for Wolfson Arizona class devices
...
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git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging
Pull staging tree patches from Greg Kroah-Hartman:
"Here's the big staging tree merge for the 3.6-rc1 merge window.
There are some patches in here outside of drivers/staging/, notibly
the iio code (which is still stradeling the staging / not staging
boundry), the pstore code, and the tracing code. All of these have
gotten acks from the various subsystem maintainers to be included in
this tree. The pstore and tracing patches are related, and are coming
here as they replace one of the android staging drivers.
Otherwise, the normal staging mess. Lots of cleanups and a few new
drivers (some iio drivers, and the large csr wireless driver
abomination.)
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>"
Fixed up trivial conflicts in drivers/staging/comedi/drivers/s626.h and
drivers/staging/gdm72xx/netlink_k.c
* tag 'staging-3.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (1108 commits)
staging: csr: delete a bunch of unused library functions
staging: csr: remove csr_utf16.c
staging: csr: remove csr_pmem.h
staging: csr: remove CsrPmemAlloc
staging: csr: remove CsrPmemFree()
staging: csr: remove CsrMemAllocDma()
staging: csr: remove CsrMemCalloc()
staging: csr: remove CsrMemAlloc()
staging: csr: remove CsrMemFree() and CsrMemFreeDma()
staging: csr: remove csr_util.h
staging: csr: remove CsrOffSetOf()
stating: csr: remove unneeded #includes in csr_util.c
staging: csr: make CsrUInt16ToHex static
staging: csr: remove CsrMemCpy()
staging: csr: remove CsrStrLen()
staging: csr: remove CsrVsnprintf()
staging: csr: remove CsrStrDup
staging: csr: remove CsrStrChr()
staging: csr: remove CsrStrNCmp
staging: csr: remove CsrStrCmp
...
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Pull first round of SCSI updates from James Bottomley:
"The most important feature of this patch set is the new async
infrastructure that makes sure async_synchronize_full() synchronizes
all domains and allows us to remove all the hacks (like having
scsi_complete_async_scans() in the device base code) and means that
the async infrastructure will "just work" in future.
The rest is assorted driver updates (aacraid, bnx2fc, virto-scsi,
megaraid, bfa, lpfc, qla2xxx, qla4xxx) plus a lot of infrastructure
work in sas and FC.
Signed-off-by: James Bottomley <JBottomley@Parallels.com>"
* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (97 commits)
[SCSI] Revert "[SCSI] fix async probe regression"
[SCSI] cleanup usages of scsi_complete_async_scans
[SCSI] queue async scan work to an async_schedule domain
[SCSI] async: make async_synchronize_full() flush all work regardless of domain
[SCSI] async: introduce 'async_domain' type
[SCSI] bfa: Fix to set correct return error codes and misc cleanup.
[SCSI] aacraid: Series 7 Async. (performance) mode support
[SCSI] aha152x: Allow use on 64bit systems
[SCSI] virtio-scsi: Add vdrv->scan for post VIRTIO_CONFIG_S_DRIVER_OK LUN scanning
[SCSI] bfa: squelch lockdep complaint with a spin_lock_init
[SCSI] qla2xxx: remove unnecessary reads of PCI_CAP_ID_EXP
[SCSI] qla4xxx: remove unnecessary read of PCI_CAP_ID_EXP
[SCSI] ufs: fix incorrect return value about SUCCESS and FAILED
[SCSI] ufs: reverse the ufshcd_is_device_present logic
[SCSI] ufs: use module_pci_driver
[SCSI] usb-storage: update usb devices for write cache quirk in quirk list.
[SCSI] usb-storage: add support for write cache quirk
[SCSI] set to WCE if usb cache quirk is present.
[SCSI] virtio-scsi: hotplug support for virtio-scsi
[SCSI] virtio-scsi: split scatterlist per target
...
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git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup changes from Tejun Heo:
"Nothing too interesting. A minor bug fix and some cleanups."
* 'for-3.6' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cgroup: Update remount documentation
cgroup: cgroup_rm_files() was calling simple_unlink() with the wrong inode
cgroup: Remove populate() documentation
cgroup: remove hierarchy_mutex
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Pull workqueue changes from Tejun Heo:
"There are three major changes.
- WQ_HIGHPRI has been reimplemented so that high priority work items
are served by worker threads with -20 nice value from dedicated
highpri worker pools.
- CPU hotplug support has been reimplemented such that idle workers
are kept across CPU hotplug events. This makes CPU hotplug cheaper
(for PM) and makes the code simpler.
- flush_kthread_work() has been reimplemented so that a work item can
be freed while executing. This removes an annoying behavior
difference between kthread_worker and workqueue."
* 'for-3.6' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
workqueue: fix spurious CPU locality WARN from process_one_work()
kthread_worker: reimplement flush_kthread_work() to allow freeing the work item being executed
kthread_worker: reorganize to prepare for flush_kthread_work() reimplementation
workqueue: simplify CPU hotplug code
workqueue: remove CPU offline trustee
workqueue: don't butcher idle workers on an offline CPU
workqueue: reimplement CPU online rebinding to handle idle workers
workqueue: drop @bind from create_worker()
workqueue: use mutex for global_cwq manager exclusion
workqueue: ROGUE workers are UNBOUND workers
workqueue: drop CPU_DYING notifier operation
workqueue: perform cpu down operations from low priority cpu_notifier()
workqueue: reimplement WQ_HIGHPRI using a separate worker_pool
workqueue: introduce NR_WORKER_POOLS and for_each_worker_pool()
workqueue: separate out worker_pool flags
workqueue: use @pool instead of @gcwq or @cpu where applicable
workqueue: factor out worker_pool from global_cwq
workqueue: don't use WQ_HIGHPRI for unbound workqueues
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Pull PCI changes from Bjorn Helgaas:
"Host bridge hotplug:
- Add MMCONFIG support for hot-added host bridges (Jiang Liu)
Device hotplug:
- Move fixups from __init to __devinit (Sebastian Andrzej Siewior)
- Call FINAL fixups for hot-added devices, too (Myron Stowe)
- Factor out generic code for P2P bridge hot-add (Yinghai Lu)
- Remove all functions in a slot, not just those with _EJx (Amos
Kong)
Dynamic resource management:
- Track bus number allocation (struct resource tree per domain)
(Yinghai Lu)
- Make P2P bridge 1K I/O windows work with resource reassignment
(Bjorn Helgaas, Yinghai Lu)
- Disable decoding while updating 64-bit BARs (Bjorn Helgaas)
Power management:
- Add PCIe runtime D3cold support (Huang Ying)
Virtualization:
- Add VFIO infrastructure (ACS, DMA source ID quirks) (Alex
Williamson)
- Add quirks for devices with broken INTx masking (Jan Kiszka)
Miscellaneous:
- Fix some PCI Express capability version issues (Myron Stowe)
- Factor out some arch code with a weak, generic, pcibios_setup()
(Myron Stowe)"
* tag 'for-3.6' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (122 commits)
PCI: hotplug: ensure a consistent return value in error case
PCI: fix undefined reference to 'pci_fixup_final_inited'
PCI: build resource code for M68K architecture
PCI: pciehp: remove unused pciehp_get_max_lnk_width(), pciehp_get_cur_lnk_width()
PCI: reorder __pci_assign_resource() (no change)
PCI: fix truncation of resource size to 32 bits
PCI: acpiphp: merge acpiphp_debug and debug
PCI: acpiphp: remove unused res_lock
sparc/PCI: replace pci_cfg_fake_ranges() with pci_read_bridge_bases()
PCI: call final fixups hot-added devices
PCI: move final fixups from __init to __devinit
x86/PCI: move final fixups from __init to __devinit
MIPS/PCI: move final fixups from __init to __devinit
PCI: support sizing P2P bridge I/O windows with 1K granularity
PCI: reimplement P2P bridge 1K I/O windows (Intel P64H2)
PCI: disable MEM decoding while updating 64-bit MEM BARs
PCI: leave MEM and IO decoding disabled during 64-bit BAR sizing, too
PCI: never discard enable/suspend/resume_early/resume fixups
PCI: release temporary reference in __nv_msi_ht_cap_quirk()
PCI: restructure 'pci_do_fixups()'
...
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Pull devicetree updates from Rob Herring:
"A small set of changes for devicetree:
- Couple of Documentation fixes
- Addition of new helper function of_node_full_name
- Improve of_parse_phandle_with_args return values
- Some NULL related sparse fixes"
Grant's busy packing.
* tag 'dt-for-3.6' of git://sources.calxeda.com/kernel/linux:
of: mtd: nuke useless const qualifier
devicetree: add helper inline for retrieving a node's full name
of: return -ENOENT when no property
usage-model.txt: fix typo machine_init->init_machine
of: Fix null pointer related warnings in base.c file
LED: Fix missing semicolon in OF documentation
of: fix a few typos in the binding documentation
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Pull networking changes from David S Miller:
1) Remove the ipv4 routing cache. Now lookups go directly into the FIB
trie and use prebuilt routes cached there.
No more garbage collection, no more rDOS attacks on the routing
cache. Instead we now get predictable and consistent performance,
no matter what the pattern of traffic we service.
This has been almost 2 years in the making. Special thanks to
Julian Anastasov, Eric Dumazet, Steffen Klassert, and others who
have helped along the way.
I'm sure that with a change of this magnitude there will be some
kind of fallout, but such things ought the be simple to fix at this
point. Luckily I'm not European so I'll be around all of August to
fix things :-)
The major stages of this work here are each fronted by a forced
merge commit whose commit message contains a top-level description
of the motivations and implementation issues.
2) Pre-demux of established ipv4 TCP sockets, saves a route demux on
input.
3) TCP SYN/ACK performance tweaks from Eric Dumazet.
4) Add namespace support for netfilter L4 conntrack helpers, from Gao
Feng.
5) Add config mechanism for Energy Efficient Ethernet to ethtool, from
Yuval Mintz.
6) Remove quadratic behavior from /proc/net/unix, from Eric Dumazet.
7) Support for connection tracker helpers in userspace, from Pablo
Neira Ayuso.
8) Allow userspace driven TX load balancing functions in TEAM driver,
from Jiri Pirko.
9) Kill off NLMSG_PUT and RTA_PUT macros, more gross stuff with
embedded gotos.
10) TCP Small Queues, essentially minimize the amount of TCP data queued
up in the packet scheduler layer. Whereas the existing BQL (Byte
Queue Limits) limits the pkt_sched --> netdevice queuing levels,
this controls the TCP --> pkt_sched queueing levels.
From Eric Dumazet.
11) Reduce the number of get_page/put_page ops done on SKB fragments,
from Alexander Duyck.
12) Implement protection against blind resets in TCP (RFC 5961), from
Eric Dumazet.
13) Support the client side of TCP Fast Open, basically the ability to
send data in the SYN exchange, from Yuchung Cheng.
Basically, the sender queues up data with a sendmsg() call using
MSG_FASTOPEN, then they do the connect() which emits the queued up
fastopen data.
14) Avoid all the problems we get into in TCP when timers or PMTU events
hit a locked socket. The TCP Small Queues changes added a
tcp_release_cb() that allows us to queue work up to the
release_sock() caller, and that's what we use here too. From Eric
Dumazet.
15) Zero copy on TX support for TUN driver, from Michael S. Tsirkin.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1870 commits)
genetlink: define lockdep_genl_is_held() when CONFIG_LOCKDEP
r8169: revert "add byte queue limit support".
ipv4: Change rt->rt_iif encoding.
net: Make skb->skb_iif always track skb->dev
ipv4: Prepare for change of rt->rt_iif encoding.
ipv4: Remove all RTCF_DIRECTSRC handliing.
ipv4: Really ignore ICMP address requests/replies.
decnet: Don't set RTCF_DIRECTSRC.
net/ipv4/ip_vti.c: Fix __rcu warnings detected by sparse.
ipv4: Remove redundant assignment
rds: set correct msg_namelen
openvswitch: potential NULL deref in sample()
tcp: dont drop MTU reduction indications
bnx2x: Add new 57840 device IDs
tcp: avoid oops in tcp_metrics and reset tcpm_stamp
niu: Change niu_rbr_fill() to use unlikely() to check niu_rbr_add_page() return value
niu: Fix to check for dma mapping errors.
net: Fix references to out-of-scope variables in put_cmsg_compat()
net: ethernet: davinci_emac: add pm_runtime support
net: ethernet: davinci_emac: Remove unnecessary #include
...
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Stefan reported a crash on a kernel before a3e5d1091c1 ("sched:
Don't call task_group() too many times in set_task_rq()"), he
found the reason to be that the multiple task_group()
invocations in set_task_rq() returned different values.
Looking at all that I found a lack of serialization and plain
wrong comments.
The below tries to fix it using an extra pointer which is
updated under the appropriate scheduler locks. Its not pretty,
but I can't really see another way given how all the cgroup
stuff works.
Reported-and-tested-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1340364965.18025.71.camel@twins
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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of (pinned) task
Current load balance scheme requires only one cpu in a
sched_group (balance_cpu) to look at other peer sched_groups for
imbalance and pull tasks towards itself from a busy cpu. Tasks
thus pulled by balance_cpu could later get picked up by cpus
that are in the same sched_group as that of balance_cpu.
This scheme however fails to pull tasks that are not allowed to
run on balance_cpu (but are allowed to run on other cpus in its
sched_group). That can affect fairness and in some worst case
scenarios cause starvation.
Consider a two core (2 threads/core) system running tasks as
below:
Core0 Core1
/ \ / \
C0 C1 C2 C3
| | | |
v v v v
F0 T1 F1 [idle]
T2
F0 = SCHED_FIFO task (pinned to C0)
F1 = SCHED_FIFO task (pinned to C2)
T1 = SCHED_OTHER task (pinned to C1)
T2 = SCHED_OTHER task (pinned to C1 and C2)
F1 could become a cpu hog, which will starve T2 unless C1 pulls
it. Between C0 and C1 however, C0 is required to look for
imbalance between cores, which will fail to pull T2 towards
Core0. T2 will starve eternally in this case. The same scenario
can arise in presence of non-rt tasks as well (say we replace F1
with high irq load).
We tackle this problem by having balance_cpu move pinned tasks
to one of its sibling cpus (where they can run). We first check
if load balance goal can be met by ignoring pinned tasks,
failing which we retry move_tasks() with a new env->dst_cpu.
This patch modifies load balance semantics on who can move load
towards a given cpu in a given sched_domain.
Before this patch, a given_cpu or a ilb_cpu acting on behalf of
an idle given_cpu is responsible for moving load to given_cpu.
With this patch applied, balance_cpu can in addition decide on
moving some load to a given_cpu.
There is a remote possibility that excess load could get moved
as a result of this (balance_cpu and given_cpu/ilb_cpu deciding
*independently* and at *same* time to move some load to a
given_cpu). However we should see less of such conflicting
decisions in practice and moreover subsequent load balance
cycles should correct the excess load moved to given_cpu.
Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Signed-off-by: Prashanth Nageshappa <prashanth@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/4FE06CDB.2060605@linux.vnet.ibm.com
[ minor edits ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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balance
While load balancing, if all tasks on the source runqueue are pinned,
we retry after excluding the corresponding source cpu. However, loop counters
env.loop and env.loop_break are not reset before retrying, which can lead
to failure in moving the tasks. In this patch we reset env.loop and
env.loop_break to their inital values before we retry.
Signed-off-by: Prashanth Nageshappa <prashanth@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/4FE06EEF.2090709@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Members of 'struct lb_env' are not in appropriate order to reuse compiler
added padding on 64bit architectures. In this patch we reorder those struct
members and help reduce the size of the structure from 96 bytes to 80
bytes on 64 bit architectures.
Suggested-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Signed-off-by: Prashanth Nageshappa <prashanth@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/4FE06DDE.7000403@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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perturbations
Traversing an entire package is not only expensive, it also leads to tasks
bouncing all over a partially idle and possible quite large package. Fix
that up by assigning a 'buddy' CPU to try to motivate. Each buddy may try
to motivate that one other CPU, if it's busy, tough, it may then try its
SMT sibling, but that's all this optimization is allowed to cost.
Sibling cache buddies are cross-wired to prevent bouncing.
4 socket 40 core + SMT Westmere box, single 30 sec tbench runs, higher is better:
clients 1 2 4 8 16 32 64 128
..........................................................................
pre 30 41 118 645 3769 6214 12233 14312
post 299 603 1211 2418 4697 6847 11606 14557
A nice increase in performance.
Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1339471112.7352.32.camel@marge.simpson.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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cpuset_track_online_cpus() is no longer present. So remove the
outdated comment and replace it with reference to cpuset_update_active_cpus()
which is its equivalent.
Also, we don't lack memory hot-unplug anymore. And David Rientjes pointed
out how it is dealt with. So update that comment as well.
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20120524141700.3692.98192.stgit@srivatsabhat.in.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Separate out the cpuset related handling for CPU/Memory online/offline.
This also helps us exploit the most obvious and basic level of optimization
that any notification mechanism (CPU/Mem online/offline) has to offer us:
"We *know* why we have been invoked. So stop pretending that we are lost,
and do only the necessary amount of processing!".
And while at it, rename scan_for_empty_cpusets() to
scan_cpusets_upon_hotplug(), which is more appropriate considering how
it is restructured.
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20120524141650.3692.48637.stgit@srivatsabhat.in.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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At present, the functions that deal with cpusets during CPU/Mem hotplug
are quite messy, since a lot of the functionality is mixed up without clear
separation. And this takes a toll on optimization as well. For example,
the function cpuset_update_active_cpus() is called on both CPU offline and CPU
online events; and it invokes scan_for_empty_cpusets(), which makes sense
only for CPU offline events. And hence, the current code ends up unnecessarily
traversing the cpuset tree during CPU online also.
As a first step towards cleaning up those functions, encapsulate the cpuset
tree traversal in a helper function, so as to facilitate upcoming changes.
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20120524141635.3692.893.stgit@srivatsabhat.in.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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In the event of CPU hotplug, the kernel modifies the cpusets' cpus_allowed
masks as and when necessary to ensure that the tasks belonging to the cpusets
have some place (online CPUs) to run on. And regular CPU hotplug is
destructive in the sense that the kernel doesn't remember the original cpuset
configurations set by the user, across hotplug operations.
However, suspend/resume (which uses CPU hotplug) is a special case in which
the kernel has the responsibility to restore the system (during resume), to
exactly the same state it was in before suspend.
In order to achieve that, do the following:
1. Don't modify cpusets during suspend/resume. At all.
In particular, don't move the tasks from one cpuset to another, and
don't modify any cpuset's cpus_allowed mask. So, simply ignore cpusets
during the CPU hotplug operations that are carried out in the
suspend/resume path.
2. However, cpusets and sched domains are related. We just want to avoid
altering cpusets alone. So, to keep the sched domains updated, build
a single sched domain (containing all active cpus) during each of the
CPU hotplug operations carried out in s/r path, effectively ignoring
the cpusets' cpus_allowed masks.
(Since userspace is frozen while doing all this, it will go unnoticed.)
3. During the last CPU online operation during resume, build the sched
domains by looking up the (unaltered) cpusets' cpus_allowed masks.
That will bring back the system to the same original state as it was in
before suspend.
Ultimately, this will not only solve the cpuset problem related to suspend
resume (ie., restores the cpusets to exactly what it was before suspend, by
not touching it at all) but also speeds up suspend/resume because we avoid
running cpuset update code for every CPU being offlined/onlined.
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20120524141611.3692.20155.stgit@srivatsabhat.in.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull the big VFS changes from Al Viro:
"This one is *big* and changes quite a few things around VFS. What's in there:
- the first of two really major architecture changes - death to open
intents.
The former is finally there; it was very long in making, but with
Miklos getting through really hard and messy final push in
fs/namei.c, we finally have it. Unlike his variant, this one
doesn't introduce struct opendata; what we have instead is
->atomic_open() taking preallocated struct file * and passing
everything via its fields.
Instead of returning struct file *, it returns -E... on error, 0
on success and 1 in "deal with it yourself" case (e.g. symlink
found on server, etc.).
See comments before fs/namei.c:atomic_open(). That made a lot of
goodies finally possible and quite a few are in that pile:
->lookup(), ->d_revalidate() and ->create() do not get struct
nameidata * anymore; ->lookup() and ->d_revalidate() get lookup
flags instead, ->create() gets "do we want it exclusive" flag.
With the introduction of new helper (kern_path_locked()) we are rid
of all struct nameidata instances outside of fs/namei.c; it's still
visible in namei.h, but not for long. Come the next cycle,
declaration will move either to fs/internal.h or to fs/namei.c
itself. [me, miklos, hch]
- The second major change: behaviour of final fput(). Now we have
__fput() done without any locks held by caller *and* not from deep
in call stack.
That obviously lifts a lot of constraints on the locking in there.
Moreover, it's legal now to call fput() from atomic contexts (which
has immediately simplified life for aio.c). We also don't need
anti-recursion logics in __scm_destroy() anymore.
There is a price, though - the damn thing has become partially
asynchronous. For fput() from normal process we are guaranteed
that pending __fput() will be done before the caller returns to
userland, exits or gets stopped for ptrace.
For kernel threads and atomic contexts it's done via
schedule_work(), so theoretically we might need a way to make sure
it's finished; so far only one such place had been found, but there
might be more.
There's flush_delayed_fput() (do all pending __fput()) and there's
__fput_sync() (fput() analog doing __fput() immediately). I hope
we won't need them often; see warnings in fs/file_table.c for
details. [me, based on task_work series from Oleg merged last
cycle]
- sync series from Jan
- large part of "death to sync_supers()" work from Artem; the only
bits missing here are exofs and ext4 ones. As far as I understand,
those are going via the exofs and ext4 trees resp.; once they are
in, we can put ->write_super() to the rest, along with the thread
calling it.
- preparatory bits from unionmount series (from dhowells).
- assorted cleanups and fixes all over the place, as usual.
This is not the last pile for this cycle; there's at least jlayton's
ESTALE work and fsfreeze series (the latter - in dire need of fixes,
so I'm not sure it'll make the cut this cycle). I'll probably throw
symlink/hardlink restrictions stuff from Kees into the next pile, too.
Plus there's a lot of misc patches I hadn't thrown into that one -
it's large enough as it is..."
* 'for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (127 commits)
ext4: switch EXT4_IOC_RESIZE_FS to mnt_want_write_file()
btrfs: switch btrfs_ioctl_balance() to mnt_want_write_file()
switch dentry_open() to struct path, make it grab references itself
spufs: shift dget/mntget towards dentry_open()
zoran: don't bother with struct file * in zoran_map
ecryptfs: don't reinvent the wheels, please - use struct completion
don't expose I_NEW inodes via dentry->d_inode
tidy up namei.c a bit
unobfuscate follow_up() a bit
ext3: pass custom EOF to generic_file_llseek_size()
ext4: use core vfs llseek code for dir seeks
vfs: allow custom EOF in generic_file_llseek code
vfs: Avoid unnecessary WB_SYNC_NONE writeback during sys_sync and reorder sync passes
vfs: Remove unnecessary flushing of block devices
vfs: Make sys_sync writeout also block device inodes
vfs: Create function for iterating over block devices
vfs: Reorder operations during sys_sync
quota: Move quota syncing to ->sync_fs method
quota: Split dquot_quota_sync() to writeback and cache flushing part
vfs: Move noop_backing_dev_info check from sync into writeback
...
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git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull power management updates from Rafael Wysocki:
- ACPI conversion to PM handling based on struct dev_pm_ops.
- Conversion of a number of platform drivers to PM handling based on
struct dev_pm_ops and removal of empty legacy PM callbacks from a
couple of PCI drivers.
- Suspend-to-both for in-kernel hibernation from Bojan Smojver.
- cpuidle fixes and cleanups from ShuoX Liu, Daniel Lezcano and Preeti
Murthy.
- cpufreq bug fixes from Jonghwa Lee and Stephen Boyd.
- Suspend and hibernate fixes from Srivatsa Bhat and Colin Cross.
- Generic PM domains framework updates.
- RTC CMOS wakeup signaling update from Paul Fox.
- sparse warnings fixes from Sachin Kamat.
- Build warnings fixes for the generic PM domains framework and PM
sysfs code.
- sysfs switch for printing device suspend times from Sameer Nanda.
- Documentation fix from Oskar Schirmer.
* tag 'pm-for-3.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (70 commits)
cpufreq: Fix sysfs deadlock with concurrent hotplug/frequency switch
EXYNOS: bugfix on retrieving old_index from freqs.old
PM / Sleep: call early resume handlers when suspend_noirq fails
PM / QoS: Use NULL pointer instead of plain integer in qos.c
PM / QoS: Use NULL pointer instead of plain integer in pm_qos.h
PM / Sleep: Require CAP_BLOCK_SUSPEND to use wake_lock/wake_unlock
PM / Sleep: Add missing static storage class specifiers in main.c
cpuilde / ACPI: remove time from acpi_processor_cx structure
cpuidle / ACPI: remove usage from acpi_processor_cx structure
cpuidle / ACPI : remove latency_ticks from acpi_processor_cx structure
rtc-cmos: report wakeups from interrupt handler
PM / Sleep: Fix build warning in sysfs.c for CONFIG_PM_SLEEP unset
PM / Domains: Fix build warning for CONFIG_PM_RUNTIME unset
olpc-xo15-sci: Use struct dev_pm_ops for power management
PM / Domains: Replace plain integer with NULL pointer in domain.c file
PM / Domains: Add missing static storage class specifier in domain.c file
PM / crypto / ux500: Use struct dev_pm_ops for power management
PM / IPMI: Remove empty legacy PCI PM callbacks
tpm_nsc: Use struct dev_pm_ops for power management
tpm_tis: Use struct dev_pm_ops for power management
...
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It doesn't matter on normal return to userland path (we'll recheck the
NOTIFY_RESUME flag anyway), but in case of exit_task_work() we'll
need that as soon as we get callbacks capable of triggering more
task_work_add().
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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... and get rid of PF_EXITING check in task_work_add().
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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task_work and rcu_head are identical now; merge them (calling the result
struct callback_head, rcu_head #define'd to it), kill separate allocation
in security/keys since we can just use cred->rcu now.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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layout based on Oleg's suggestion; single-linked list,
task->task_works points to the last element, forward pointer
from said last element points to head. I'd still prefer
much more regular scheme with two pointers in task_work,
but...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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get rid of the only user of ->data; this is _not_ the final variant - in the
end we'll have task_work and rcu_head identical and just use cred->rcu,
at which point the separate allocation will be gone completely.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer core changes from Ingo Molnar:
"Continued cleanups of the core time and NTP code, plus more nohz work
preparing for tick-less userspace execution."
* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
time: Rework timekeeping functions to take timekeeper ptr as argument
time: Move xtime_nsec adjustment underflow handling timekeeping_adjust
time: Move arch_gettimeoffset() usage into timekeeping_get_ns()
time: Refactor accumulation of nsecs to secs
time: Condense timekeeper.xtime into xtime_sec
time: Explicitly use u32 instead of int for shift values
time: Whitespace cleanups per Ingo%27s requests
nohz: Move next idle expiry time record into idle logic area
nohz: Move ts->idle_calls incrementation into strict idle logic
nohz: Rename ts->idle_tick to ts->last_tick
nohz: Make nohz API agnostic against idle ticks cputime accounting
nohz: Separate idle sleeping time accounting from nohz logic
timers: Improve get_next_timer_interrupt()
timers: Add accounting of non deferrable timers
timers: Consolidate base->next_timer update
timers: Create detach_if_pending() and use it
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull smp/hotplug changes from Ingo Molnar:
"Various cleanups to the SMP hotplug code - a continuing effort of
Thomas et al"
* 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
smpboot: Remove leftover declaration
smp: Remove num_booting_cpus()
smp: Remove ipi_call_lock[_irq]()/ipi_call_unlock[_irq]()
POWERPC: Smp: remove call to ipi_call_lock()/ipi_call_unlock()
SPARC: SMP: Remove call to ipi_call_lock_irq()/ipi_call_unlock_irq()
ia64: SMP: Remove call to ipi_call_lock_irq()/ipi_call_unlock_irq()
x86-smp-remove-call-to-ipi_call_lock-ipi_call_unlock
tile: SMP: Remove call to ipi_call_lock()/ipi_call_unlock()
S390: Smp: remove call to ipi_call_lock()/ipi_call_unlock()
parisc: Smp: remove call to ipi_call_lock()/ipi_call_unlock()
mn10300: SMP: Remove call to ipi_call_lock()/ipi_call_unlock()
hexagon: SMP: Remove call to ipi_call_lock()/ipi_call_unlock()
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf events changes from Ingo Molnar:
"- kernel side:
- Intel uncore PMU support for Nehalem and Sandy Bridge CPUs, we
support both the events available via the MSR and via the PCI
access space.
- various uprobes cleanups and restructurings
- PMU driver quirks by microcode version and required x86 microcode
loader cleanups/robustization
- various tracing robustness updates
- static keys: remove obsolete static_branch()
- tooling side:
- GTK browser improvements
- perf report browser: support screenshots to file
- more automated tests
- perf kvm improvements
- perf bench refinements
- build environment improvements
- pipe mode improvements
- libtraceevent updates, we have now hopefully merged most bits with
the out of tree forked code base
... and many other goodies."
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (138 commits)
tracing: Check for allocation failure in __tracing_open()
perf/x86: Fix intel_perfmon_event_mapformatting
jump label: Remove static_branch()
tracepoint: Use static_key_false(), since static_branch() is deprecated
perf/x86: Uncore filter support for SandyBridge-EP
perf/x86: Detect number of instances of uncore CBox
perf/x86: Fix event constraint for SandyBridge-EP C-Box
perf/x86: Use 0xff as pseudo code for fixed uncore event
perf/x86: Save a few bytes in 'struct x86_pmu'
perf/x86: Add a microcode revision check for SNB-PEBS
perf/x86: Improve debug output in check_hw_exists()
perf/x86/amd: Unify AMD's generic and family 15h pmus
perf/x86: Move Intel specific code to intel_pmu_init()
perf/x86: Rename Intel specific macros
perf/x86: Fix USER/KERNEL tagging of samples
perf tools: Split event symbols arrays to hw and sw parts
perf tools: Split out PE_VALUE_SYM parsing token to SW and HW tokens
perf tools: Add empty rule for new line in event syntax parsing
perf test: Use ARRAY_SIZE in parse events tests
tools lib traceevent: Cleanup realloc use
...
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull RCU changes from Ingo Molnar:
"Quoting from Paul, the major features of this series are:
1. Preventing latency spikes of more than 200 microseconds for
kernels built with NR_CPUS=4096, which is reportedly becoming the
default for some distros. This is a first step, as it does not
help with systems that actually -have- 4096 CPUs (work on this case
is in progress, but is not yet ready for mainline).
This category also includes improving concurrency of rcu_barrier(),
placed here due to conflicts. Posted to LKML at:
https://lkml.org/lkml/2012/6/22/381
Note that patches 18-22 of that series have been defered to 3.7, as
they have not yet proven themselves to be mainline-ready (and yes,
these are the ones intended to get rid of RCU's latency spikes for
systems that actually have 4096 CPUs).
2. Updates to documentation and rcutorture fixes, the latter category
including improvements to rcu_barrier() testing. Posted to LKML at
http://lkml.indiana.edu/hypermail/linux/kernel/1206.1/04094.html.
3. Miscellaneous fixes posted to LKML at:
https://lkml.org/lkml/2012/6/22/500
with the exception of the last commit, which was posted here:
http://www.gossamer-threads.com/lists/linux/kernel/1561830
4. RCU_FAST_NO_HZ fixes and improvements. Posted to LKML at:
http://lkml.indiana.edu/hypermail/linux/kernel/1206.1/00006.html
http://www.gossamer-threads.com/lists/linux/kernel/1561833
The first four patches of the first series went into 3.5 to fix a
regression.
5. Code-style fixes. These were posted to LKML at
http://lkml.indiana.edu/hypermail/linux/kernel/1205.2/01180.html
http://lkml.indiana.edu/hypermail/linux/kernel/1205.2/01181.html"
* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (48 commits)
rcu: Fix broken strings in RCU's source code.
rcu: Fix code-style issues involving "else"
rcu: Introduce check for callback list/count mismatch
rcu: Make RCU_FAST_NO_HZ respect nohz= boot parameter
rcu: Fix qlen_lazy breakage
rcu: Round FAST_NO_HZ lazy timeout to nearest second
rcu: The rcu_needs_cpu() function is not a quiescent state
rcu: Dump only the current CPU's buffers for idle-entry/exit warnings
rcu: Add check for CPUs going offline with callbacks queued
rcu: Disable preemption in rcu_blocking_is_gp()
rcu: Prevent uninitialized string in RCU CPU stall info
rcu: Fix rcu_is_cpu_idle() #ifdef in TINY_RCU
rcu: Split RCU core processing out of __call_rcu()
rcu: Prevent __call_rcu() from invoking RCU core on offline CPUs
rcu: Make __call_rcu() handle invocation from idle
rcu: Remove function versions of __kfree_rcu and __is_kfree_rcu_offset
rcu: Consolidate tree/tiny __rcu_read_{,un}lock() implementations
rcu: Remove return value from rcu_assign_pointer()
key: Remove extraneous parentheses from rcu_assign_keypointer()
rcu: Remove return value from RCU_INIT_POINTER()
...
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25511a4776 "workqueue: reimplement CPU online rebinding to handle idle
workers" added CPU locality sanity check in process_one_work(). It
triggers if a worker is executing on a different CPU without UNBOUND
or REBIND set.
This works for all normal workers but rescuers can trigger this
spuriously when they're serving the unbound or a disassociated
global_cwq - rescuers don't have either flag set and thus its
gcwq->cpu can be a different value including %WORK_CPU_UNBOUND.
Fix it by additionally testing %GCWQ_DISASSOCIATED.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
LKML-Refence: <20120721213656.GA7783@linux.vnet.ibm.com>
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item being executed
kthread_worker provides minimalistic workqueue-like interface for
users which need a dedicated worker thread (e.g. for realtime
priority). It has basic queue, flush_work, flush_worker operations
which mostly match the workqueue counterparts; however, due to the way
flush_work() is implemented, it has a noticeable difference of not
allowing work items to be freed while being executed.
While the current users of kthread_worker are okay with the current
behavior, the restriction does impede some valid use cases. Also,
removing this difference isn't difficult and actually makes the code
easier to understand.
This patch reimplements flush_kthread_work() such that it uses a
flush_work item instead of queue/done sequence numbers.
Signed-off-by: Tejun Heo <tj@kernel.org>
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Make the following two non-functional changes.
* Separate out insert_kthread_work() from queue_kthread_work().
* Relocate struct kthread_flush_work and kthread_flush_work_fn()
definitions above flush_kthread_work().
v2: Added lockdep_assert_held() in insert_kthread_work() as suggested
by Andy Walls.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Andy Walls <awalls@md.metrocast.net>
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Merge emailed kgdb dmesg fixups patches from Anton Vorontsov:
"The dmesg command appears to be broken after the printk rework. The
old logic in the kdb code makes no sense in terms of current
printk/logging storage format, and KDB simply hangs forever upon
entering 'dmesg' command.
The first patch revives the command by switching to kmsg_dumper
iterator. As a side-effect, the code is now much more simpler.
A few changes were needed in the printk.c: we needed unlocked variant
of the kmsg_dumper iterator, but these can surely wait for 3.6.
It's probably too late even for the first patch to go to 3.5, but I'll
try to convince otherwise. :-) Here we go:
- The current code is broken for sure, and has no hope to work at
all. It is a regression
- The new code works for me, and probably works for everyone else;
- If it compiles (and I urge everyone to compile-test it on your
setup), it hardly can make things worse."
* Merge emailed patches from Anton Vorontsov: (4 commits)
kdb: Switch to nolock variants of kmsg_dump functions
printk: Implement some unlocked kmsg_dump functions
printk: Remove kdb_syslog_data
kdb: Revive dmesg command
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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>
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If used from KDB, the locked variants are prone to deadlocks (suppose we
got to the debugger w/ the logbuf lock held).
So, we have to implement a few routines that grab no logbuf lock.
Yet we don't need these functions in modules, so we don't export them.
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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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>
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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>
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In response to an async related regression James noted:
"My theory is that this is an init problem: The assumption in a lot of
our code is that async_synchronize_full() waits for everything ... even
the domain specific async schedules, which isn't true."
...so make this assumption true.
Each domain, including the default one, registers itself on a global domain
list when work is scheduled. Once all entries complete it exits that
list. Waiting for the list to be empty syncs all in-flight work across
all domains.
Domains can opt-out of global syncing if they are declared as exclusive
ASYNC_DOMAIN_EXCLUSIVE(). All stack-based domains have been declared
exclusive since the domain may go out of scope as soon as the last work
item completes.
Statically declared domains are mostly ok, but async_unregister_domain()
is there to close any theoretical races with pending
async_synchronize_full waiters at module removal time.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Reported-by: Meelis Roos <mroos@linux.ee>
Reported-by: Eldad Zack <eldadzack@gmail.com>
Tested-by: Eldad Zack <eldad@fogrefinery.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
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This is in preparation for teaching async_synchronize_full() to sync all
pending async work, and not just on the async_running domain. This
conversion is functionally equivalent, just embedding the existing list
in a new async_domain type.
The .registered attribute is used in a later patch to distinguish
between domains that want to be flushed by async_synchronize_full()
versus those that only expect async_synchronize_{full|cookie}_domain to
be used for flushing.
[jejb: add async.h to scsi_priv.h for struct async_domain]
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Tested-by: Eldad Zack <eldad@fogrefinery.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
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There are tools like makedumpfile and vmcore-dmesg which can extract
kernel log buffer from vmcore. Since we introduced structured logging,
that functionality is broken. Now user space tools need to know about
"struct log" and offsets of various fields to be able to parse struct
log data and extract text message or dictonary.
This patch exports some of the fields.
Currently I am not exporting log "level" info as that is a bitfield and
offsetof() bitfields can't be calculated. But if people start asking for
log level info in the output then we probably either need to seprate
out "level" or use bit shift operations for flags and level.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Acked-by: Kay Sievers <kay@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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