Merge branch 'master' of /home/davem/src/GIT/linux-2.6/

Conflicts:
	arch/sparc/Kconfig
This commit is contained in:
David S. Miller
2009-09-11 20:35:13 -07:00
970 changed files with 65083 additions and 24075 deletions
+77
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@@ -743,3 +743,80 @@ Revised:
RCU, realtime RCU, sleepable RCU, performance.
"
}
@article{PaulEMcKenney2008RCUOSR
,author="Paul E. McKenney and Jonathan Walpole"
,title="Introducing technology into the {Linux} kernel: a case study"
,Year="2008"
,journal="SIGOPS Oper. Syst. Rev."
,volume="42"
,number="5"
,pages="4--17"
,issn="0163-5980"
,doi={http://doi.acm.org/10.1145/1400097.1400099}
,publisher="ACM"
,address="New York, NY, USA"
,annotation={
Linux changed RCU to a far greater degree than RCU has changed Linux.
}
}
@unpublished{PaulEMcKenney2008HierarchicalRCU
,Author="Paul E. McKenney"
,Title="Hierarchical {RCU}"
,month="November"
,day="3"
,year="2008"
,note="Available:
\url{http://lwn.net/Articles/305782/}
[Viewed November 6, 2008]"
,annotation="
RCU with combining-tree-based grace-period detection,
permitting it to handle thousands of CPUs.
"
}
@conference{PaulEMcKenney2009MaliciousURCU
,Author="Paul E. McKenney"
,Title="Using a Malicious User-Level {RCU} to Torture {RCU}-Based Algorithms"
,Booktitle="linux.conf.au 2009"
,month="January"
,year="2009"
,address="Hobart, Australia"
,note="Available:
\url{http://www.rdrop.com/users/paulmck/RCU/urcutorture.2009.01.22a.pdf}
[Viewed February 2, 2009]"
,annotation="
Realtime RCU and torture-testing RCU uses.
"
}
@unpublished{MathieuDesnoyers2009URCU
,Author="Mathieu Desnoyers"
,Title="[{RFC} git tree] Userspace {RCU} (urcu) for {Linux}"
,month="February"
,day="5"
,year="2009"
,note="Available:
\url{http://lkml.org/lkml/2009/2/5/572}
\url{git://lttng.org/userspace-rcu.git}
[Viewed February 20, 2009]"
,annotation="
Mathieu Desnoyers's user-space RCU implementation.
git://lttng.org/userspace-rcu.git
"
}
@unpublished{PaulEMcKenney2009BloatWatchRCU
,Author="Paul E. McKenney"
,Title="{RCU}: The {Bloatwatch} Edition"
,month="March"
,day="17"
,year="2009"
,note="Available:
\url{http://lwn.net/Articles/323929/}
[Viewed March 20, 2009]"
,annotation="
Uniprocessor assumptions allow simplified RCU implementation.
"
}
+25 -9
View File
@@ -2,14 +2,13 @@ RCU on Uniprocessor Systems
A common misconception is that, on UP systems, the call_rcu() primitive
may immediately invoke its function, and that the synchronize_rcu()
primitive may return immediately. The basis of this misconception
may immediately invoke its function. The basis of this misconception
is that since there is only one CPU, it should not be necessary to
wait for anything else to get done, since there are no other CPUs for
anything else to be happening on. Although this approach will -sort- -of-
work a surprising amount of the time, it is a very bad idea in general.
This document presents three examples that demonstrate exactly how bad an
idea this is.
This document presents three examples that demonstrate exactly how bad
an idea this is.
Example 1: softirq Suicide
@@ -82,11 +81,18 @@ Quick Quiz #2: What locking restriction must RCU callbacks respect?
Summary
Permitting call_rcu() to immediately invoke its arguments or permitting
synchronize_rcu() to immediately return breaks RCU, even on a UP system.
So do not do it! Even on a UP system, the RCU infrastructure -must-
respect grace periods, and -must- invoke callbacks from a known environment
in which no locks are held.
Permitting call_rcu() to immediately invoke its arguments breaks RCU,
even on a UP system. So do not do it! Even on a UP system, the RCU
infrastructure -must- respect grace periods, and -must- invoke callbacks
from a known environment in which no locks are held.
It -is- safe for synchronize_sched() and synchronize_rcu_bh() to return
immediately on an UP system. It is also safe for synchronize_rcu()
to return immediately on UP systems, except when running preemptable
RCU.
Quick Quiz #3: Why can't synchronize_rcu() return immediately on
UP systems running preemptable RCU?
Answer to Quick Quiz #1:
@@ -117,3 +123,13 @@ Answer to Quick Quiz #2:
callbacks acquire locks directly. However, a great many RCU
callbacks do acquire locks -indirectly-, for example, via
the kfree() primitive.
Answer to Quick Quiz #3:
Why can't synchronize_rcu() return immediately on UP systems
running preemptable RCU?
Because some other task might have been preempted in the middle
of an RCU read-side critical section. If synchronize_rcu()
simply immediately returned, it would prematurely signal the
end of the grace period, which would come as a nasty shock to
that other thread when it started running again.
+15 -5
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@@ -11,7 +11,10 @@ over a rather long period of time, but improvements are always welcome!
structure is updated more than about 10% of the time, then
you should strongly consider some other approach, unless
detailed performance measurements show that RCU is nonetheless
the right tool for the job.
the right tool for the job. Yes, you might think of RCU
as simply cutting overhead off of the readers and imposing it
on the writers. That is exactly why normal uses of RCU will
do much more reading than updating.
Another exception is where performance is not an issue, and RCU
provides a simpler implementation. An example of this situation
@@ -240,10 +243,11 @@ over a rather long period of time, but improvements are always welcome!
instead need to use synchronize_irq() or synchronize_sched().
12. Any lock acquired by an RCU callback must be acquired elsewhere
with irq disabled, e.g., via spin_lock_irqsave(). Failing to
disable irq on a given acquisition of that lock will result in
deadlock as soon as the RCU callback happens to interrupt that
acquisition's critical section.
with softirq disabled, e.g., via spin_lock_irqsave(),
spin_lock_bh(), etc. Failing to disable irq on a given
acquisition of that lock will result in deadlock as soon as the
RCU callback happens to interrupt that acquisition's critical
section.
13. RCU callbacks can be and are executed in parallel. In many cases,
the callback code simply wrappers around kfree(), so that this
@@ -310,3 +314,9 @@ over a rather long period of time, but improvements are always welcome!
Because these primitives only wait for pre-existing readers,
it is the caller's responsibility to guarantee safety to
any subsequent readers.
16. The various RCU read-side primitives do -not- contain memory
barriers. The CPU (and in some cases, the compiler) is free
to reorder code into and out of RCU read-side critical sections.
It is the responsibility of the RCU update-side primitives to
deal with this.
+5 -5
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@@ -36,7 +36,7 @@ o How can the updater tell when a grace period has completed
executed in user mode, or executed in the idle loop, we can
safely free up that item.
Preemptible variants of RCU (CONFIG_PREEMPT_RCU) get the
Preemptible variants of RCU (CONFIG_TREE_PREEMPT_RCU) get the
same effect, but require that the readers manipulate CPU-local
counters. These counters allow limited types of blocking
within RCU read-side critical sections. SRCU also uses
@@ -79,10 +79,10 @@ o I hear that RCU is patented? What is with that?
o I hear that RCU needs work in order to support realtime kernels?
This work is largely completed. Realtime-friendly RCU can be
enabled via the CONFIG_PREEMPT_RCU kernel configuration parameter.
However, work is in progress for enabling priority boosting of
preempted RCU read-side critical sections. This is needed if you
have CPU-bound realtime threads.
enabled via the CONFIG_TREE_PREEMPT_RCU kernel configuration
parameter. However, work is in progress for enabling priority
boosting of preempted RCU read-side critical sections. This is
needed if you have CPU-bound realtime threads.
o Where can I find more information on RCU?
+7
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@@ -170,6 +170,13 @@ module invokes call_rcu() from timers, you will need to first cancel all
the timers, and only then invoke rcu_barrier() to wait for any remaining
RCU callbacks to complete.
Of course, if you module uses call_rcu_bh(), you will need to invoke
rcu_barrier_bh() before unloading. Similarly, if your module uses
call_rcu_sched(), you will need to invoke rcu_barrier_sched() before
unloading. If your module uses call_rcu(), call_rcu_bh(), -and-
call_rcu_sched(), then you will need to invoke each of rcu_barrier(),
rcu_barrier_bh(), and rcu_barrier_sched().
Implementing rcu_barrier()
+21 -2
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@@ -76,8 +76,10 @@ torture_type The type of RCU to test: "rcu" for the rcu_read_lock() API,
"rcu_sync" for rcu_read_lock() with synchronous reclamation,
"rcu_bh" for the rcu_read_lock_bh() API, "rcu_bh_sync" for
rcu_read_lock_bh() with synchronous reclamation, "srcu" for
the "srcu_read_lock()" API, and "sched" for the use of
preempt_disable() together with synchronize_sched().
the "srcu_read_lock()" API, "sched" for the use of
preempt_disable() together with synchronize_sched(),
and "sched_expedited" for the use of preempt_disable()
with synchronize_sched_expedited().
verbose Enable debug printk()s. Default is disabled.
@@ -162,6 +164,23 @@ of the "old" and "current" counters for the corresponding CPU. The
"idx" value maps the "old" and "current" values to the underlying array,
and is useful for debugging.
Similarly, sched_expedited RCU provides the following:
sched_expedited-torture: rtc: d0000000016c1880 ver: 1090796 tfle: 0 rta: 1090796 rtaf: 0 rtf: 1090787 rtmbe: 0 nt: 27713319
sched_expedited-torture: Reader Pipe: 12660320201 95875 0 0 0 0 0 0 0 0 0
sched_expedited-torture: Reader Batch: 12660424885 0 0 0 0 0 0 0 0 0 0
sched_expedited-torture: Free-Block Circulation: 1090795 1090795 1090794 1090793 1090792 1090791 1090790 1090789 1090788 1090787 0
state: -1 / 0:0 3:0 4:0
As before, the first four lines are similar to those for RCU.
The last line shows the task-migration state. The first number is
-1 if synchronize_sched_expedited() is idle, -2 if in the process of
posting wakeups to the migration kthreads, and N when waiting on CPU N.
Each of the colon-separated fields following the "/" is a CPU:state pair.
Valid states are "0" for idle, "1" for waiting for quiescent state,
"2" for passed through quiescent state, and "3" when a race with a
CPU-hotplug event forces use of the synchronize_sched() primitive.
USAGE
+3 -4
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@@ -191,8 +191,7 @@ rcu/rcuhier (which displays the struct rcu_node hierarchy).
The output of "cat rcu/rcudata" looks as follows:
rcu:
rcu:
rcu_sched:
0 c=17829 g=17829 pq=1 pqc=17829 qp=0 dt=10951/1 dn=0 df=1101 of=0 ri=36 ql=0 b=10
1 c=17829 g=17829 pq=1 pqc=17829 qp=0 dt=16117/1 dn=0 df=1015 of=0 ri=0 ql=0 b=10
2 c=17829 g=17829 pq=1 pqc=17829 qp=0 dt=1445/1 dn=0 df=1839 of=0 ri=0 ql=0 b=10
@@ -306,7 +305,7 @@ comma-separated-variable spreadsheet format.
The output of "cat rcu/rcugp" looks as follows:
rcu: completed=33062 gpnum=33063
rcu_sched: completed=33062 gpnum=33063
rcu_bh: completed=464 gpnum=464
Again, this output is for both "rcu" and "rcu_bh". The fields are
@@ -413,7 +412,7 @@ o Each element of the form "1/1 0:127 ^0" represents one struct
The output of "cat rcu/rcu_pending" looks as follows:
rcu:
rcu_sched:
0 np=255892 qsp=53936 cbr=0 cng=14417 gpc=10033 gps=24320 nf=6445 nn=146741
1 np=261224 qsp=54638 cbr=0 cng=25723 gpc=16310 gps=2849 nf=5912 nn=155792
2 np=237496 qsp=49664 cbr=0 cng=2762 gpc=45478 gps=1762 nf=1201 nn=136629
+15 -7
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@@ -136,10 +136,10 @@ rcu_read_lock()
Used by a reader to inform the reclaimer that the reader is
entering an RCU read-side critical section. It is illegal
to block while in an RCU read-side critical section, though
kernels built with CONFIG_PREEMPT_RCU can preempt RCU read-side
critical sections. Any RCU-protected data structure accessed
during an RCU read-side critical section is guaranteed to remain
unreclaimed for the full duration of that critical section.
kernels built with CONFIG_TREE_PREEMPT_RCU can preempt RCU
read-side critical sections. Any RCU-protected data structure
accessed during an RCU read-side critical section is guaranteed to
remain unreclaimed for the full duration of that critical section.
Reference counts may be used in conjunction with RCU to maintain
longer-term references to data structures.
@@ -785,6 +785,7 @@ RCU pointer/list traversal:
rcu_dereference
list_for_each_entry_rcu
hlist_for_each_entry_rcu
hlist_nulls_for_each_entry_rcu
list_for_each_continue_rcu (to be deprecated in favor of new
list_for_each_entry_continue_rcu)
@@ -807,19 +808,23 @@ RCU: Critical sections Grace period Barrier
rcu_read_lock synchronize_net rcu_barrier
rcu_read_unlock synchronize_rcu
synchronize_rcu_expedited
call_rcu
bh: Critical sections Grace period Barrier
rcu_read_lock_bh call_rcu_bh rcu_barrier_bh
rcu_read_unlock_bh
rcu_read_unlock_bh synchronize_rcu_bh
synchronize_rcu_bh_expedited
sched: Critical sections Grace period Barrier
[preempt_disable] synchronize_sched rcu_barrier_sched
[and friends] call_rcu_sched
rcu_read_lock_sched synchronize_sched rcu_barrier_sched
rcu_read_unlock_sched call_rcu_sched
[preempt_disable] synchronize_sched_expedited
[and friends]
SRCU: Critical sections Grace period Barrier
@@ -827,6 +832,9 @@ SRCU: Critical sections Grace period Barrier
srcu_read_lock synchronize_srcu N/A
srcu_read_unlock
SRCU: Initialization/cleanup
init_srcu_struct
cleanup_srcu_struct
See the comment headers in the source code (or the docbook generated
from them) for more information.
+24 -27
View File
@@ -206,24 +206,6 @@ Who: Len Brown <len.brown@intel.com>
---------------------------
What: libata spindown skipping and warning
When: Dec 2008
Why: Some halt(8) implementations synchronize caches for and spin
down libata disks because libata didn't use to spin down disk on
system halt (only synchronized caches).
Spin down on system halt is now implemented. sysfs node
/sys/class/scsi_disk/h:c:i:l/manage_start_stop is present if
spin down support is available.
Because issuing spin down command to an already spun down disk
makes some disks spin up just to spin down again, libata tracks
device spindown status to skip the extra spindown command and
warn about it.
This is to give userspace tools the time to get updated and will
be removed after userspace is reasonably updated.
Who: Tejun Heo <htejun@gmail.com>
---------------------------
What: i386/x86_64 bzImage symlinks
When: April 2010
@@ -394,15 +376,6 @@ Who: Thomas Gleixner <tglx@linutronix.de>
-----------------------------
What: obsolete generic irq defines and typedefs
When: 2.6.30
Why: The defines and typedefs (hw_interrupt_type, no_irq_type, irq_desc_t)
have been kept around for migration reasons. After more than two years
it's time to remove them finally
Who: Thomas Gleixner <tglx@linutronix.de>
---------------------------
What: fakephp and associated sysfs files in /sys/bus/pci/slots/
When: 2011
Why: In 2.6.27, the semantics of /sys/bus/pci/slots was redefined to
@@ -468,3 +441,27 @@ Why: cpu_policy_rwsem has a new cleaner definition making it local to
cpufreq core and contained inside cpufreq.c. Other dependent
drivers should not use it in order to safely avoid lockdep issues.
Who: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
----------------------------
What: sound-slot/service-* module aliases and related clutters in
sound/sound_core.c
When: August 2010
Why: OSS sound_core grabs all legacy minors (0-255) of SOUND_MAJOR
(14) and requests modules using custom sound-slot/service-*
module aliases. The only benefit of doing this is allowing
use of custom module aliases which might as well be considered
a bug at this point. This preemptive claiming prevents
alternative OSS implementations.
Till the feature is removed, the kernel will be requesting
both sound-slot/service-* and the standard char-major-* module
aliases and allow turning off the pre-claiming selectively via
CONFIG_SOUND_OSS_CORE_PRECLAIM and soundcore.preclaim_oss
kernel parameter.
After the transition phase is complete, both the custom module
aliases and switches to disable it will go away. This removal
will also allow making ALSA OSS emulation independent of
sound_core. The dependency will be broken then too.
Who: Tejun Heo <tj@kernel.org>
+98
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@@ -0,0 +1,98 @@
The NFS client
==============
The NFS version 2 protocol was first documented in RFC1094 (March 1989).
Since then two more major releases of NFS have been published, with NFSv3
being documented in RFC1813 (June 1995), and NFSv4 in RFC3530 (April
2003).
The Linux NFS client currently supports all the above published versions,
and work is in progress on adding support for minor version 1 of the NFSv4
protocol.
The purpose of this document is to provide information on some of the
upcall interfaces that are used in order to provide the NFS client with
some of the information that it requires in order to fully comply with
the NFS spec.
The DNS resolver
================
NFSv4 allows for one server to refer the NFS client to data that has been
migrated onto another server by means of the special "fs_locations"
attribute. See
http://tools.ietf.org/html/rfc3530#section-6
and
http://tools.ietf.org/html/draft-ietf-nfsv4-referrals-00
The fs_locations information can take the form of either an ip address and
a path, or a DNS hostname and a path. The latter requires the NFS client to
do a DNS lookup in order to mount the new volume, and hence the need for an
upcall to allow userland to provide this service.
Assuming that the user has the 'rpc_pipefs' filesystem mounted in the usual
/var/lib/nfs/rpc_pipefs, the upcall consists of the following steps:
(1) The process checks the dns_resolve cache to see if it contains a
valid entry. If so, it returns that entry and exits.
(2) If no valid entry exists, the helper script '/sbin/nfs_cache_getent'
(may be changed using the 'nfs.cache_getent' kernel boot parameter)
is run, with two arguments:
- the cache name, "dns_resolve"
- the hostname to resolve
(3) After looking up the corresponding ip address, the helper script
writes the result into the rpc_pipefs pseudo-file
'/var/lib/nfs/rpc_pipefs/cache/dns_resolve/channel'
in the following (text) format:
"<ip address> <hostname> <ttl>\n"
Where <ip address> is in the usual IPv4 (123.456.78.90) or IPv6
(ffee:ddcc:bbaa:9988:7766:5544:3322:1100, ffee::1100, ...) format.
<hostname> is identical to the second argument of the helper
script, and <ttl> is the 'time to live' of this cache entry (in
units of seconds).
Note: If <ip address> is invalid, say the string "0", then a negative
entry is created, which will cause the kernel to treat the hostname
as having no valid DNS translation.
A basic sample /sbin/nfs_cache_getent
=====================================
#!/bin/bash
#
ttl=600
#
cut=/usr/bin/cut
getent=/usr/bin/getent
rpc_pipefs=/var/lib/nfs/rpc_pipefs
#
die()
{
echo "Usage: $0 cache_name entry_name"
exit 1
}
[ $# -lt 2 ] && die
cachename="$1"
cache_path=${rpc_pipefs}/cache/${cachename}/channel
case "${cachename}" in
dns_resolve)
name="$2"
result="$(${getent} hosts ${name} | ${cut} -f1 -d\ )"
[ -z "${result}" ] && result="0"
;;
*)
die
;;
esac
echo "${result} ${name} ${ttl}" >${cache_path}
+34
View File
@@ -1503,6 +1503,14 @@ and is between 256 and 4096 characters. It is defined in the file
[NFS] set the TCP port on which the NFSv4 callback
channel should listen.
nfs.cache_getent=
[NFS] sets the pathname to the program which is used
to update the NFS client cache entries.
nfs.cache_getent_timeout=
[NFS] sets the timeout after which an attempt to
update a cache entry is deemed to have failed.
nfs.idmap_cache_timeout=
[NFS] set the maximum lifetime for idmapper cache
entries.
@@ -2395,6 +2403,18 @@ and is between 256 and 4096 characters. It is defined in the file
stifb= [HW]
Format: bpp:<bpp1>[:<bpp2>[:<bpp3>...]]
sunrpc.min_resvport=
sunrpc.max_resvport=
[NFS,SUNRPC]
SunRPC servers often require that client requests
originate from a privileged port (i.e. a port in the
range 0 < portnr < 1024).
An administrator who wishes to reserve some of these
ports for other uses may adjust the range that the
kernel's sunrpc client considers to be privileged
using these two parameters to set the minimum and
maximum port values.
sunrpc.pool_mode=
[NFS]
Control how the NFS server code allocates CPUs to
@@ -2411,6 +2431,15 @@ and is between 256 and 4096 characters. It is defined in the file
pernode one pool for each NUMA node (equivalent
to global on non-NUMA machines)
sunrpc.tcp_slot_table_entries=
sunrpc.udp_slot_table_entries=
[NFS,SUNRPC]
Sets the upper limit on the number of simultaneous
RPC calls that can be sent from the client to a
server. Increasing these values may allow you to
improve throughput, but will also increase the
amount of memory reserved for use by the client.
swiotlb= [IA-64] Number of I/O TLB slabs
switches= [HW,M68k]
@@ -2480,6 +2509,11 @@ and is between 256 and 4096 characters. It is defined in the file
trace_buf_size=nn[KMG]
[FTRACE] will set tracing buffer size.
trace_event=[event-list]
[FTRACE] Set and start specified trace events in order
to facilitate early boot debugging.
See also Documentation/trace/events.txt
trix= [HW,OSS] MediaTrix AudioTrix Pro
Format:
<io>,<irq>,<dma>,<dma2>,<sb_io>,<sb_irq>,<sb_dma>,<mpu_io>,<mpu_irq>
+38 -1
View File
@@ -26,7 +26,7 @@ This document has the following sections:
- Notes on accessing payload contents
- Defining a key type
- Request-key callback service
- Key access filesystem
- Garbage collection
============
@@ -113,6 +113,9 @@ Each key has a number of attributes:
(*) Dead. The key's type was unregistered, and so the key is now useless.
Keys in the last three states are subject to garbage collection. See the
section on "Garbage collection".
====================
KEY SERVICE OVERVIEW
@@ -754,6 +757,26 @@ The keyctl syscall functions are:
successful.
(*) Install the calling process's session keyring on its parent.
long keyctl(KEYCTL_SESSION_TO_PARENT);
This functions attempts to install the calling process's session keyring
on to the calling process's parent, replacing the parent's current session
keyring.
The calling process must have the same ownership as its parent, the
keyring must have the same ownership as the calling process, the calling
process must have LINK permission on the keyring and the active LSM module
mustn't deny permission, otherwise error EPERM will be returned.
Error ENOMEM will be returned if there was insufficient memory to complete
the operation, otherwise 0 will be returned to indicate success.
The keyring will be replaced next time the parent process leaves the
kernel and resumes executing userspace.
===============
KERNEL SERVICES
===============
@@ -1231,3 +1254,17 @@ by executing:
In this case, the program isn't required to actually attach the key to a ring;
the rings are provided for reference.
==================
GARBAGE COLLECTION
==================
Dead keys (for which the type has been removed) will be automatically unlinked
from those keyrings that point to them and deleted as soon as possible by a
background garbage collector.
Similarly, revoked and expired keys will be garbage collected, but only after a
certain amount of time has passed. This time is set as a number of seconds in:
/proc/sys/kernel/keys/gc_delay
+31
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@@ -27,6 +27,13 @@ To trigger an intermediate memory scan:
# echo scan > /sys/kernel/debug/kmemleak
To clear the list of all current possible memory leaks:
# echo clear > /sys/kernel/debug/kmemleak
New leaks will then come up upon reading /sys/kernel/debug/kmemleak
again.
Note that the orphan objects are listed in the order they were allocated
and one object at the beginning of the list may cause other subsequent
objects to be reported as orphan.
@@ -42,6 +49,9 @@ Memory scanning parameters can be modified at run-time by writing to the
scan=<secs> - set the automatic memory scanning period in seconds
(default 600, 0 to stop the automatic scanning)
scan - trigger a memory scan
clear - clear list of current memory leak suspects, done by
marking all current reported unreferenced objects grey
dump=<addr> - dump information about the object found at <addr>
Kmemleak can also be disabled at boot-time by passing "kmemleak=off" on
the kernel command line.
@@ -86,6 +96,27 @@ avoid this, kmemleak can also store the number of values pointing to an
address inside the block address range that need to be found so that the
block is not considered a leak. One example is __vmalloc().
Testing specific sections with kmemleak
---------------------------------------
Upon initial bootup your /sys/kernel/debug/kmemleak output page may be
quite extensive. This can also be the case if you have very buggy code
when doing development. To work around these situations you can use the
'clear' command to clear all reported unreferenced objects from the
/sys/kernel/debug/kmemleak output. By issuing a 'scan' after a 'clear'
you can find new unreferenced objects; this should help with testing
specific sections of code.
To test a critical section on demand with a clean kmemleak do:
# echo clear > /sys/kernel/debug/kmemleak
... test your kernel or modules ...
# echo scan > /sys/kernel/debug/kmemleak
Then as usual to get your report with:
# cat /sys/kernel/debug/kmemleak
Kmemleak API
------------
+7
View File
@@ -495,6 +495,13 @@ and for each vararg a long value. So e.g. for a debug entry with a format
string plus two varargs one would need to allocate a (3 * sizeof(long))
byte data area in the debug_register() function.
IMPORTANT: Using "%s" in sprintf event functions is dangerous. You can only
use "%s" in the sprintf event functions, if the memory for the passed string is
available as long as the debug feature exists. The reason behind this is that
due to performance considerations only a pointer to the string is stored in
the debug feature. If you log a string that is freed afterwards, you will get
an OOPS when inspecting the debug feature, because then the debug feature will
access the already freed memory.
NOTE: If using the sprintf view do NOT use other event/exception functions
than the sprintf-event and -exception functions.
@@ -60,6 +60,12 @@ Prior to version 0.9.0rc4 options had a 'snd_' prefix. This was removed.
slots - Reserve the slot index for the given driver.
This option takes multiple strings.
See "Module Autoloading Support" section for details.
debug - Specifies the debug message level
(0 = disable debug prints, 1 = normal debug messages,
2 = verbose debug messages)
This option appears only when CONFIG_SND_DEBUG=y.
This option can be dynamically changed via sysfs
/sys/modules/snd/parameters/debug file.
Module snd-pcm-oss
------------------
@@ -513,6 +519,26 @@ Prior to version 0.9.0rc4 options had a 'snd_' prefix. This was removed.
or input, but you may use this module for any application which
requires a sound card (like RealPlayer).
pcm_devs - Number of PCM devices assigned to each card
(default = 1, up to 4)
pcm_substreams - Number of PCM substreams assigned to each PCM
(default = 8, up to 16)
hrtimer - Use hrtimer (=1, default) or system timer (=0)
fake_buffer - Fake buffer allocations (default = 1)
When multiple PCM devices are created, snd-dummy gives different
behavior to each PCM device:
0 = interleaved with mmap support
1 = non-interleaved with mmap support
2 = interleaved without mmap
3 = non-interleaved without mmap
As default, snd-dummy drivers doesn't allocate the real buffers
but either ignores read/write or mmap a single dummy page to all
buffer pages, in order to save the resouces. If your apps need
the read/ written buffer data to be consistent, pass fake_buffer=0
option.
The power-management is supported.
Module snd-echo3g
@@ -768,6 +794,10 @@ Prior to version 0.9.0rc4 options had a 'snd_' prefix. This was removed.
bdl_pos_adj - Specifies the DMA IRQ timing delay in samples.
Passing -1 will make the driver to choose the appropriate
value based on the controller chip.
patch - Specifies the early "patch" files to modify the HD-audio
setup before initializing the codecs. This option is
available only when CONFIG_SND_HDA_PATCH_LOADER=y is set.
See HD-Audio.txt for details.
[Single (global) options]
single_cmd - Use single immediate commands to communicate with
+24 -9
View File
@@ -114,8 +114,8 @@ ALC662/663/272
samsung-nc10 Samsung NC10 mini notebook
auto auto-config reading BIOS (default)
ALC882/885
==========
ALC882/883/885/888/889
======================
3stack-dig 3-jack with SPDIF I/O
6stack-dig 6-jack digital with SPDIF I/O
arima Arima W820Di1
@@ -127,12 +127,8 @@ ALC882/885
mbp3 Macbook Pro rev3
imac24 iMac 24'' with jack detection
w2jc ASUS W2JC
auto auto-config reading BIOS (default)
ALC883/888
==========
3stack-dig 3-jack with SPDIF I/O
6stack-dig 6-jack digital with SPDIF I/O
3stack-2ch-dig 3-jack with SPDIF I/O (ALC883)
alc883-6stack-dig 6-jack digital with SPDIF I/O (ALC883)
3stack-6ch 3-jack 6-channel
3stack-6ch-dig 3-jack 6-channel with SPDIF I/O
6stack-dig-demo 6-jack digital for Intel demo board
@@ -140,6 +136,7 @@ ALC883/888
acer-aspire Acer Aspire 9810
acer-aspire-4930g Acer Aspire 4930G
acer-aspire-6530g Acer Aspire 6530G
acer-aspire-7730g Acer Aspire 7730G
acer-aspire-8930g Acer Aspire 8930G
medion Medion Laptops
medion-md2 Medion MD2
@@ -155,10 +152,13 @@ ALC883/888
3stack-hp HP machines with 3stack (Lucknow, Samba boards)
6stack-dell Dell machines with 6stack (Inspiron 530)
mitac Mitac 8252D
clevo-m540r Clevo M540R (6ch + digital)
clevo-m720 Clevo M720 laptop series
fujitsu-pi2515 Fujitsu AMILO Pi2515
fujitsu-xa3530 Fujitsu AMILO XA3530
3stack-6ch-intel Intel DG33* boards
intel-alc889a Intel IbexPeak with ALC889A
intel-x58 Intel DX58 with ALC889
asus-p5q ASUS P5Q-EM boards
mb31 MacBook 3,1
sony-vaio-tt Sony VAIO TT
@@ -229,7 +229,7 @@ AD1984
======
basic default configuration
thinkpad Lenovo Thinkpad T61/X61
dell Dell T3400
dell_desktop Dell T3400
AD1986A
=======
@@ -258,6 +258,7 @@ Conexant 5045
laptop-micsense Laptop with Mic sense (old model fujitsu)
laptop-hpmicsense Laptop with HP and Mic senses
benq Benq R55E
laptop-hp530 HP 530 laptop
test for testing/debugging purpose, almost all controls
can be adjusted. Appearing only when compiled with
$CONFIG_SND_DEBUG=y
@@ -278,9 +279,16 @@ Conexant 5051
hp-dv6736 HP dv6736
lenovo-x200 Lenovo X200 laptop
Conexant 5066
=============
laptop Basic Laptop config (default)
dell-laptop Dell laptops
olpc-xo-1_5 OLPC XO 1.5
STAC9200
========
ref Reference board
oqo OQO Model 2
dell-d21 Dell (unknown)
dell-d22 Dell (unknown)
dell-d23 Dell (unknown)
@@ -368,10 +376,12 @@ STAC92HD73*
===========
ref Reference board
no-jd BIOS setup but without jack-detection
intel Intel DG45* mobos
dell-m6-amic Dell desktops/laptops with analog mics
dell-m6-dmic Dell desktops/laptops with digital mics
dell-m6 Dell desktops/laptops with both type of mics
dell-eq Dell desktops/laptops
alienware Alienware M17x
auto BIOS setup (default)
STAC92HD83*
@@ -385,3 +395,8 @@ STAC9872
========
vaio VAIO laptop without SPDIF
auto BIOS setup (default)
Cirrus Logic CS4206/4207
========================
mbp55 MacBook Pro 5,5
auto BIOS setup (default)
+64
View File
@@ -138,6 +138,10 @@ override the BIOS setup or to provide more comprehensive features.
The driver checks PCI SSID and looks through the static configuration
table until any matching entry is found. If you have a new machine,
you may see a message like below:
------------------------------------------------------------------------
hda_codec: ALC880: BIOS auto-probing.
------------------------------------------------------------------------
Meanwhile, in the earlier versions, you would see a message like:
------------------------------------------------------------------------
hda_codec: Unknown model for ALC880, trying auto-probe from BIOS...
------------------------------------------------------------------------
@@ -403,6 +407,66 @@ re-configure based on that state, run like below:
------------------------------------------------------------------------
Early Patching
~~~~~~~~~~~~~~
When CONFIG_SND_HDA_PATCH_LOADER=y is set, you can pass a "patch" as a
firmware file for modifying the HD-audio setup before initializing the
codec. This can work basically like the reconfiguration via sysfs in
the above, but it does it before the first codec configuration.
A patch file is a plain text file which looks like below:
------------------------------------------------------------------------
[codec]
0x12345678 0xabcd1234 2
[model]
auto
[pincfg]
0x12 0x411111f0
[verb]
0x20 0x500 0x03
0x20 0x400 0xff
[hint]
hp_detect = yes
------------------------------------------------------------------------
The file needs to have a line `[codec]`. The next line should contain
three numbers indicating the codec vendor-id (0x12345678 in the
example), the codec subsystem-id (0xabcd1234) and the address (2) of
the codec. The rest patch entries are applied to this specified codec
until another codec entry is given.
The `[model]` line allows to change the model name of the each codec.
In the example above, it will be changed to model=auto.
Note that this overrides the module option.
After the `[pincfg]` line, the contents are parsed as the initial
default pin-configurations just like `user_pin_configs` sysfs above.
The values can be shown in user_pin_configs sysfs file, too.
Similarly, the lines after `[verb]` are parsed as `init_verbs`
sysfs entries, and the lines after `[hint]` are parsed as `hints`
sysfs entries, respectively.
The hd-audio driver reads the file via request_firmware(). Thus,
a patch file has to be located on the appropriate firmware path,
typically, /lib/firmware. For example, when you pass the option
`patch=hda-init.fw`, the file /lib/firmware/hda-init-fw must be
present.
The patch module option is specific to each card instance, and you
need to give one file name for each instance, separated by commas.
For example, if you have two cards, one for an on-board analog and one
for an HDMI video board, you may pass patch option like below:
------------------------------------------------------------------------
options snd-hda-intel patch=on-board-patch,hdmi-patch
------------------------------------------------------------------------
Power-Saving
~~~~~~~~~~~~
The power-saving is a kind of auto-suspend of the device. When the
+16
View File
@@ -19,6 +19,7 @@ Currently, these files might (depending on your configuration)
show up in /proc/sys/kernel:
- acpi_video_flags
- acct
- callhome [ S390 only ]
- auto_msgmni
- core_pattern
- core_uses_pid
@@ -91,6 +92,21 @@ valid for 30 seconds.
==============================================================
callhome:
Controls the kernel's callhome behavior in case of a kernel panic.
The s390 hardware allows an operating system to send a notification
to a service organization (callhome) in case of an operating system panic.
When the value in this file is 0 (which is the default behavior)
nothing happens in case of a kernel panic. If this value is set to "1"
the complete kernel oops message is send to the IBM customer service
organization in case the mainframe the Linux operating system is running
on has a service contract with IBM.
==============================================================
core_pattern:
core_pattern is used to specify a core dumpfile pattern name.
+9
View File
@@ -83,6 +83,15 @@ When reading one of these enable files, there are four results:
X - there is a mixture of events enabled and disabled
? - this file does not affect any event
2.3 Boot option
---------------
In order to facilitate early boot debugging, use boot option:
trace_event=[event-list]
The format of this boot option is the same as described in section 2.1.
3. Defining an event-enabled tracepoint
=======================================
+36 -32
View File
@@ -85,26 +85,19 @@ of ftrace. Here is a list of some of the key files:
This file holds the output of the trace in a human
readable format (described below).
latency_trace:
This file shows the same trace but the information
is organized more to display possible latencies
in the system (described below).
trace_pipe:
The output is the same as the "trace" file but this
file is meant to be streamed with live tracing.
Reads from this file will block until new data
is retrieved. Unlike the "trace" and "latency_trace"
files, this file is a consumer. This means reading
from this file causes sequential reads to display
more current data. Once data is read from this
file, it is consumed, and will not be read
again with a sequential read. The "trace" and
"latency_trace" files are static, and if the
tracer is not adding more data, they will display
the same information every time they are read.
Reads from this file will block until new data is
retrieved. Unlike the "trace" file, this file is a
consumer. This means reading from this file causes
sequential reads to display more current data. Once
data is read from this file, it is consumed, and
will not be read again with a sequential read. The
"trace" file is static, and if the tracer is not
adding more data,they will display the same
information every time they are read.
trace_options:
@@ -117,10 +110,10 @@ of ftrace. Here is a list of some of the key files:
Some of the tracers record the max latency.
For example, the time interrupts are disabled.
This time is saved in this file. The max trace
will also be stored, and displayed by either
"trace" or "latency_trace". A new max trace will
only be recorded if the latency is greater than
the value in this file. (in microseconds)
will also be stored, and displayed by "trace".
A new max trace will only be recorded if the
latency is greater than the value in this
file. (in microseconds)
buffer_size_kb:
@@ -210,7 +203,7 @@ Here is the list of current tracers that may be configured.
the trace with the longest max latency.
See tracing_max_latency. When a new max is recorded,
it replaces the old trace. It is best to view this
trace via the latency_trace file.
trace with the latency-format option enabled.
"preemptoff"
@@ -307,8 +300,8 @@ the lowest priority thread (pid 0).
Latency trace format
--------------------
For traces that display latency times, the latency_trace file
gives somewhat more information to see why a latency happened.
When the latency-format option is enabled, the trace file gives
somewhat more information to see why a latency happened.
Here is a typical trace.
# tracer: irqsoff
@@ -380,9 +373,10 @@ explains which is which.
The above is mostly meaningful for kernel developers.
time: This differs from the trace file output. The trace file output
includes an absolute timestamp. The timestamp used by the
latency_trace file is relative to the start of the trace.
time: When the latency-format option is enabled, the trace file
output includes a timestamp relative to the start of the
trace. This differs from the output when latency-format
is disabled, which includes an absolute timestamp.
delay: This is just to help catch your eye a bit better. And
needs to be fixed to be only relative to the same CPU.
@@ -440,7 +434,8 @@ Here are the available options:
sym-addr:
bash-4000 [01] 1477.606694: simple_strtoul <c0339346>
verbose - This deals with the latency_trace file.
verbose - This deals with the trace file when the
latency-format option is enabled.
bash 4000 1 0 00000000 00010a95 [58127d26] 1720.415ms \
(+0.000ms): simple_strtoul (strict_strtoul)
@@ -472,7 +467,7 @@ Here are the available options:
the app is no longer running
The lookup is performed when you read
trace,trace_pipe,latency_trace. Example:
trace,trace_pipe. Example:
a.out-1623 [000] 40874.465068: /root/a.out[+0x480] <-/root/a.out[+0
x494] <- /root/a.out[+0x4a8] <- /lib/libc-2.7.so[+0x1e1a6]
@@ -481,6 +476,11 @@ x494] <- /root/a.out[+0x4a8] <- /lib/libc-2.7.so[+0x1e1a6]
every scheduling event. Will add overhead if
there's a lot of tasks running at once.
latency-format - This option changes the trace. When
it is enabled, the trace displays
additional information about the
latencies, as described in "Latency
trace format".
sched_switch
------------
@@ -596,12 +596,13 @@ To reset the maximum, echo 0 into tracing_max_latency. Here is
an example:
# echo irqsoff > current_tracer
# echo latency-format > trace_options
# echo 0 > tracing_max_latency
# echo 1 > tracing_enabled
# ls -ltr
[...]
# echo 0 > tracing_enabled
# cat latency_trace
# cat trace
# tracer: irqsoff
#
irqsoff latency trace v1.1.5 on 2.6.26
@@ -703,12 +704,13 @@ which preemption was disabled. The control of preemptoff tracer
is much like the irqsoff tracer.
# echo preemptoff > current_tracer
# echo latency-format > trace_options
# echo 0 > tracing_max_latency
# echo 1 > tracing_enabled
# ls -ltr
[...]
# echo 0 > tracing_enabled
# cat latency_trace
# cat trace
# tracer: preemptoff
#
preemptoff latency trace v1.1.5 on 2.6.26-rc8
@@ -850,12 +852,13 @@ Again, using this trace is much like the irqsoff and preemptoff
tracers.
# echo preemptirqsoff > current_tracer
# echo latency-format > trace_options
# echo 0 > tracing_max_latency
# echo 1 > tracing_enabled
# ls -ltr
[...]
# echo 0 > tracing_enabled
# cat latency_trace
# cat trace
# tracer: preemptirqsoff
#
preemptirqsoff latency trace v1.1.5 on 2.6.26-rc8
@@ -1012,11 +1015,12 @@ Instead of performing an 'ls', we will run 'sleep 1' under
'chrt' which changes the priority of the task.
# echo wakeup > current_tracer
# echo latency-format > trace_options
# echo 0 > tracing_max_latency
# echo 1 > tracing_enabled
# chrt -f 5 sleep 1
# echo 0 > tracing_enabled
# cat latency_trace
# cat trace
# tracer: wakeup
#
wakeup latency trace v1.1.5 on 2.6.26-rc8

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