Implement code computing proportions of events of different type (like code in
lib/proportions.c) but allowing periods to have different lengths. This allows
us to have aging periods of fixed wallclock time which gives better proportion
estimates given the hugely varying throughput of different devices - previous
measuring of aging period by number of events has the problem that a reasonable
period length for a system with low-end USB stick is not a reasonable period
length for a system with high-end storage array resulting either in too slow
proportion updates or too fluctuating proportion updates.
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
/proc/net/unix has quadratic behavior, and can hold unix_table_lock for
a while if high number of unix sockets are alive. (90 ms for 200k
sockets...)
We already have a hash table, so its quite easy to use it.
Problem is unbound sockets are still hashed in a single hash slot
(unix_socket_table[UNIX_HASH_TABLE])
This patch also spreads unbound sockets to 256 hash slots, to speedup
both /proc/net/unix and unix_diag.
Time to read /proc/net/unix with 200k unix sockets :
(time dd if=/proc/net/unix of=/dev/null bs=4k)
before : 520 secs
after : 2 secs
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
add struct net as a parameter of inet_getpeer_v[4,6],
use net to replace &init_net.
and modify some places to provide net for inet_getpeer_v[4,6]
Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
now inetpeer doesn't support namespace,the information will
be leaking across namespace.
this patch move the global vars v4_peers and v6_peers to
netns_ipv4 and netns_ipv6 as a field peers.
add struct pernet_operations inetpeer_ops to initial pernet
inetpeer data.
and change family_to_base and inet_getpeer to support namespace.
Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull perf fixes from Ingo Molnar:
"A bit larger than what I'd wish for - half of it is due to hw driver
updates to Intel Ivy-Bridge which info got recently released,
cycles:pp should work there now too, amongst other things. (but we
are generally making exceptions for hardware enablement of this type.)
There are also callchain fixes in it - responding to mostly
theoretical (but valid) concerns. The tooling side sports perf.data
endianness/portability fixes which did not make it for the merge
window - and various other fixes as well."
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (26 commits)
perf/x86: Check user address explicitly in copy_from_user_nmi()
perf/x86: Check if user fp is valid
perf: Limit callchains to 127
perf/x86: Allow multiple stacks
perf/x86: Update SNB PEBS constraints
perf/x86: Enable/Add IvyBridge hardware support
perf/x86: Implement cycles:p for SNB/IVB
perf/x86: Fix Intel shared extra MSR allocation
x86/decoder: Fix bsr/bsf/jmpe decoding with operand-size prefix
perf: Remove duplicate invocation on perf_event_for_each
perf uprobes: Remove unnecessary check before strlist__delete
perf symbols: Check for valid dso before creating map
perf evsel: Fix 32 bit values endianity swap for sample_id_all header
perf session: Handle endianity swap on sample_id_all header data
perf symbols: Handle different endians properly during symbol load
perf evlist: Pass third argument to ioctl explicitly
perf tools: Update ioctl documentation for PERF_IOC_FLAG_GROUP
perf tools: Make --version show kernel version instead of pull req tag
perf tools: Check if callchain is corrupted
perf callchain: Make callchain cursors TLS
...
Pull drm intel and exynos fixes from Dave Airlie:
"A bunch of fixes for Intel and exynos, nothing too major, a new intel
PCI ID, and a fix for CRT detection."
* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
drm/i915: pch_irq_handler -> {ibx, cpt}_irq_handler
char/agp: add another Ironlake host bridge
drm/i915: fix up ivb plane 3 pageflips
drm/exynos: fixed blending for hdmi graphic layer
drm/exynos: Remove dummy encoder get_crtc operation implementation
drm/exynos: Keep a reference to frame buffer GEM objects
drm/exynos: Don't cast GEM object to Exynos GEM object when not needed
drm/exynos: DRIVER_BUS_PLATFORM is not a driver feature
drm/exynos: fixed size type.
drm/exynos: Use DRM_FORMAT_{NV12, YUV420} instead of DRM_FORMAT_{NV12M, YUV420M}
drm/i915: hold forcewake around ring hw init
drm/i915: Mark the ringbuffers as being in the GTT domain
drm/i915/crt: Do not rely upon the HPD presence pin
drm/i915: Reset last_retired_head when resetting ring
Instead of reading in the resource groups when gfs2 is checking
for free space to allocate from, gfs2 can store the necessary infromation
in the resource group's lvb. Also, instead of searching for unlinked
inodes in every resource group that's checked for free space, gfs2 can
store the number of unlinked but inodes in the lvb, and only check for
unlinked inodes if it will find some.
The first time a resource group is locked, the lvb must initialized.
Since this involves counting the unlinked inodes in the resource group,
this takes a little extra time. But after that, if the resource group
is locked with GL_SKIP, the buffer head won't be read in unless it's
actually needed.
Enabling the resource groups lvbs is done via the rgrplvb mount option. If
this option isn't set, the lvbs will still be set and updated, but they won't
be verfied or used by the filesystem. To safely turn on this option, all of
the nodes mounting the filesystem must be running code with this patch, and
the filesystem must have been completely unmounted since they were updated.
Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Intel-iommu initialization doesn't currently reserve the memory
used for the IOMMU registers. This can allow the pci resource
allocator to assign a device BAR to the same address as the
IOMMU registers. This can cause some not so nice side affects
when the driver ioremap's that region.
Introduced two helper functions to map & unmap the IOMMU
registers as well as simplify the init and exit paths.
Signed-off-by: Donald Dutile <ddutile@redhat.com>
Acked-by: Chris Wright <chrisw@redhat.com>
Cc: iommu@lists.linux-foundation.org
Cc: suresh.b.siddha@intel.com
Cc: dwmw2@infradead.org
Link: http://lkml.kernel.org/r/1338845342-12464-3-git-send-email-ddutile@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Add vga_switcheroo_get_client_state() to get the current state of the
client. This is necessary to determine the proper initial state of
audio clients in HD-audio driver.
Acked-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
* 'exynos-drm-fixes' of git://git.infradead.org/users/kmpark/linux-samsung:
drm/exynos: fixed blending for hdmi graphic layer
drm/exynos: Remove dummy encoder get_crtc operation implementation
drm/exynos: Keep a reference to frame buffer GEM objects
drm/exynos: Don't cast GEM object to Exynos GEM object when not needed
drm/exynos: DRIVER_BUS_PLATFORM is not a driver feature
drm/exynos: fixed size type.
drm/exynos: Use DRM_FORMAT_{NV12, YUV420} instead of DRM_FORMAT_{NV12M, YUV420M}
Commit 026cee0086 "params:
<level>_initcall-like kernel parameters" set old-style module
parameters to level 0. And we call those level 0 calls where we used
to, early in start_kernel().
We also loop through the initcall levels and call the levelled
module_params before the corresponding initcall. Unfortunately level
0 is early_init(), so we call the standard module_param calls twice.
(Turns out most things don't care, but at least ubi.mtd does).
Change the level to -1 for standard module_param calls.
Reported-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: stable@kernel.org
The DMA controller like Nvidia's Tegra Dma controller
supports the different slave requestor id from different slave.
This need to be configure in dma controller to handle the request
properly.
Adding the slave-id in the slave configuration so that information
can be passed from client when configuring for slave.
Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
Zero is written at clear_tid_address when the process exits. This
functionality is used by pthread_join().
We already have sys_set_tid_address() to change this address for the
current task but there is no way to obtain it from user space.
Without the ability to find this address and dump it we can't restore
pthread'ed apps which call pthread_join() once they have been restored.
This patch introduces the PR_GET_TID_ADDRESS prctl option which allows
the current process to obtain own clear_tid_address.
This feature is available iif CONFIG_CHECKPOINT_RESTORE is set.
[akpm@linux-foundation.org: fix prctl numbering]
Signed-off-by: Andrew Vagin <avagin@openvz.org>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Pedro Alves <palves@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Tejun Heo <tj@kernel.org>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A fix for commit b32dfe3771 ("c/r: prctl: add ability to set new
mm_struct::exe_file").
After removing mm->num_exe_file_vmas kernel keeps mm->exe_file until
final mmput(), it never becomes NULL while task is alive.
We can check for other mapped files in mm instead of checking
mm->num_exe_file_vmas, and mark mm with flag MMF_EXE_FILE_CHANGED in
order to forbid second changing of mm->exe_file.
Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Reviewed-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Matt Helsley <matthltc@us.ibm.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch extends the kernel's ethtool interface by adding support
for 2 new EEE commands - get_eee and set_eee.
Thanks goes to Giuseppe Cavallaro for his original patch adding this support.
Signed-off-by: Yuval Mintz <yuvalmin@broadcom.com>
Signed-off-by: Eilon Greenstein <eilong@broadcom.com>
Reviewed-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The mask option allows you put all address belonging that mask into
the same recent slot. This can be useful in case that recent is used
to detect attacks from the same network segment.
Tested for backward compatibility.
Signed-off-by: Denys Fedoryshchenko <denys@visp.net.lb>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch adds namespace support for cttimeout.
Acked-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Since the sysctl data for l[3|4]proto now resides in pernet nf_proto_net.
We can now remove this unused fields from struct nf_contrack_l[3,4]proto.
Acked-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch adds namespace support for ICMPv6 protocol tracker.
Acked-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch adds namespace support for ICMP protocol tracker.
Acked-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch adds namespace support for UDP protocol tracker.
Acked-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch adds namespace support for TCP protocol tracker.
Acked-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch adds namespace support for the generic layer 4 protocol
tracker.
Acked-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch prepares the namespace support for layer 3 protocol trackers.
Basically, this modifies the following interfaces:
* nf_ct_l3proto_[un]register_sysctl.
* nf_conntrack_l3proto_[un]register.
We add a new nf_ct_l3proto_net is used to get the pernet data of l3proto.
This adds rhe new struct nf_ip_net that is used to store the sysctl header
and l3proto_ipv4,l4proto_tcp(6),l4proto_udp(6),l4proto_icmp(v6) because the
protos such tcp and tcp6 use the same data,so making nf_ip_net as a field
of netns_ct is the easiest way to manager it.
This patch also adds init_net to struct nf_conntrack_l3proto to initial
the layer 3 protocol pernet data.
Acked-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch prepares the namespace support for layer 4 protocol trackers.
Basically, this modifies the following interfaces:
* nf_ct_[un]register_sysctl
* nf_conntrack_l4proto_[un]register
to include the namespace parameter. We still use init_net in this patch
to prepare the ground for follow-up patches for each layer 4 protocol
tracker.
We add a new net_id field to struct nf_conntrack_l4proto that is used
to store the pernet_operations id for each layer 4 protocol tracker.
Note that AF_INET6's protocols do not need to do sysctl compat. Thus,
we only register compat sysctl when l4proto.l3proto != AF_INET6.
Acked-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Implement a new "fail-open" mode where packets are not dropped
upon queue-full condition. This mode can be enabled/disabled per
queue using netlink NFQA_CFG_FLAGS & NFQA_CFG_MASK attributes.
Signed-off-by: Krishna Kumar <krkumar2@in.ibm.com>
Signed-off-by: Vivek Kashyap <vivk@us.ibm.com>
Signed-off-by: Sridhar Samudrala <samudrala@us.ibm.com>
It was scheduled to be removed.
Cc: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
It was scheduled to be removed.
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch addresses two issues:
a) Fix usage of u32 and __be32 that causes endianess warnings via sparse.
b) Ensure consistent hashing in a cluster that is composed of big and
little endian systems. Thus, we obtain the same hash mark in an
heterogeneous cluster.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Hans Schillstrom <hans@schillstrom.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Add the F3 PCI id of F15h, model 0x10 to pci_ids.h and to the amd_nb
code which generates the list of northbridges on an AMD box. Shorten
define name while at it so that it fits into pci_ids.h.
Acked-by: Clemens Ladisch <clemens@ladisch.de>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Andreas Herrmann <andreas.herrmann3@amd.com>
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
When a CPU is entering dyntick-idle mode, tick_nohz_stop_sched_tick()
calls rcu_needs_cpu() see if RCU needs that CPU, and, if not, computes the
next wakeup time based on the timer wheels. Only later, when actually
entering the idle loop, rcu_prepare_for_idle() will be invoked. In some
cases, rcu_prepare_for_idle() will post timers to wake the CPU back up.
But all for naught: The next wakeup time for the CPU has already been
computed, and posting a timer afterwards does not force that wakeup
time to be recomputed. This means that rcu_prepare_for_idle()'s have
no effect.
This is not a problem on a busy system because something else will wake
up the CPU soon enough. However, on lightly loaded systems, the CPU
might stay asleep for a considerable length of time. If that CPU has
a callback that the rest of the system is waiting on, the system might
run very slowly or (in theory) even hang.
This commit avoids this problem by having rcu_needs_cpu() give
tick_nohz_stop_sched_tick() an estimate of when RCU will need the CPU
to wake back up, which tick_nohz_stop_sched_tick() takes into account
when programming the CPU's wakeup time. An alternative approach is
for rcu_prepare_for_idle() to use hrtimers instead of normal timers,
but timers are much more efficient than are hrtimers for frequently
and repeatedly posting and cancelling a given timer, which is exactly
what RCU_FAST_NO_HZ does.
Reported-by: Pascal Chapperon <pascal.chapperon@wanadoo.fr>
Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Tested-by: Pascal Chapperon <pascal.chapperon@wanadoo.fr>
In the current code, a short dyntick-idle interval (where there is
at least one non-lazy callback on the CPU) and a long dyntick-idle
interval (where there are only lazy callbacks on the CPU) are traced
identically, which can be less than helpful. This commit therefore
emits different event traces in these two cases.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Tested-by: Pascal Chapperon <pascal.chapperon@wanadoo.fr>
It was introduced for memcg to iterate cgroup hierarchy without
holding cgroup_mutex, but soon after that it was replaced with
a lockless way in memcg.
No one used hierarchy_mutex since that, so remove it.
Signed-off-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Redesign all the off-channel code, getting rid of
the generic off-channel work concept, replacing
it with a simple remain-on-channel list.
This fixes a number of small issues with the ROC
implementation:
* offloaded remain-on-channel couldn't be queued,
now we can queue it as well, if needed
* in iwlwifi (the only user) offloaded ROC is
mutually exclusive with scanning, use the new
queue to handle that case -- I expect that it
will later depend on a HW flag
The bigger issue though is that there's a bad bug
in the current implementation: if we get a mgmt
TX request while HW roc is active, and this new
request has a wait time, we actually schedule a
software ROC instead since we can't guarantee the
existing offloaded ROC will still be that long.
To fix this, the queuing mechanism was needed.
The queuing mechanism for offloaded ROC isn't yet
optimal, ideally we should add API to have the HW
extend the ROC if needed. We could add that later
but for now use a software implementation.
Overall, this unifies the behaviour between the
offloaded and software-implemented case as much
as possible.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
The IDLE handling in HW off-channel is broken right
now since we turn off IDLE only when the off-channel
period already started. Therefore, all drivers that
use it today (only iwlwifi!) must support off-channel
while idle, so playing with idle isn't needed at all.
Off-channel in general, since it's no longer used for
authentication/association, shouldn't affect PS, so
also remove that logic.
Also document a small caveat for reporting TX status
from off-channel frames in HW remain-on-channel.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
The remain-on-channel time validation shouldn't
depend on the value of HZ, as it does now with
the check against jiffies, since then you might
use a value that works on one system but not on
another. Fix it by checking against a minimum
that's fixed.
Also add validation of the wait duration for a
management frame TX since this also translates
into remain-on-channel internally.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
I found this core on a BCM4322, a PCI card in the Linksys WRT610N V1.
This core is not used by the driver, this patch just makes ssb show the
correct name.
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Now that we've removed all uses of the set_channel
API except for the monitor channel and in libertas,
clarify this. Split the libertas mesh use into a
new libertas_set_mesh_channel() operation, just to
keep backward compatibility, and rename the normal
set_channel() to set_monitor_channel().
Also describe the desired set_monitor_channel()
semantics more clearly.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Pull ACPI and Power Management changes from Len Brown.
This does an evil merge to fix up what I think is a mismerge by Len to
the gma500 driver, and restore it to the mainline state.
In that driver, both branches had commented out the call to
acpi_video_register(), and Len resolved the merge to that commented-out
version.
However, in mainline, further changes by Alan (commit d839ede47a:
"gma500: opregion and ACPI" to be exact) had re-enabled the ACPI video
registration, so the current state of the driver seems to want it.
Alan is apparently still feeling the effects of partying with the Queen,
so he didn't reply to my query, but I'll do the evil merge anyway.
* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux:
ACPI: fix acpi_bus.h build warnings when ACPI is not enabled
drivers: acpi: Fix dependency for ACPI_HOTPLUG_CPU
tools/power turbostat: fix IVB support
tools/power turbostat: fix un-intended affinity of forked program
ACPI video: use after input_unregister_device()
gma500: don't register the ACPI video bus
acpi_video: Intel video is not always i915
acpi_video: fix leaking PCI references
ACPI: Ignore invalid _PSS entries, but use valid ones
ACPI battery: only refresh the sysfs files when pertinent information changes
commit 5faa5df1fa (inetpeer: Invalidate the inetpeer tree along with
the routing cache) added a race :
Before freeing an inetpeer, we must respect a RCU grace period, and make
sure no user will attempt to increase refcnt.
inetpeer_invalidate_tree() waits for a RCU grace period before inserting
inetpeer tree into gc_list and waking the worker. At that time, no
concurrent lookup can find a inetpeer in this tree.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Acked-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The rdpmc instruction is faster than the equivelant rdmsr call,
so use it when possible in the kernel.
The perfctr kernel patches did this, after extensive testing showed
rdpmc to always be faster (One can look in etc/costs in the perfctr-2.6
package to see a historical list of the overhead).
I have done some tests on a 3.2 kernel, the kernel module I used
was included in the first posting of this patch:
rdmsr rdpmc
Core2 T9900: 203.9 cycles 30.9 cycles
AMD fam0fh: 56.2 cycles 9.8 cycles
Atom 6/28/2: 129.7 cycles 50.6 cycles
The speedup of using rdpmc is large.
[ It's probably possible (and desirable) to do this without
requiring a new field in the hw_perf_event structure, but
the fixed events make this tricky. ]
Signed-off-by: Vince Weaver <vweaver1@eecs.utk.edu>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/alpine.DEB.2.00.1203011724030.26934@cl320.eecs.utk.edu
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Kill the no longer needed uprobes_srcu/uprobe_srcu_id code.
It doesn't really work anyway. synchronize_srcu() can only
synchronize with the code "inside" the
srcu_read_lock/srcu_read_unlock section, while
uprobe_pre_sstep_notifier() does srcu_read_lock() _after_ we
already hit the breakpoint.
I guess this probably works "in practice". synchronize_srcu() is
slow and it implies synchronize_sched(), and the probed task
enters the non- preemptible section at the start of exception
handler. Still this is not right at least in theory, and
task->uprobe_srcu_id blows task_struct.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Anton Arapov <anton@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20120529193008.GG8057@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
