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Merge branch 'linus' into core/softlockup

Browse Source 
Conflicts:

	kernel/softlockup.c

Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Ingo Molnar
2008-07-15 23:12:58 +02:00
parent 3e2f69fdd1 b9d2252c1e
commit 1e09481365
2669 changed files with 173734 additions and 98819 deletions
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.gitignore
+9 -3
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@@ -3,6 +3,10 @@
# subdirectories here. Add them in the ".gitignore" file
# in that subdirectory instead.
#
# NOTE! Please use 'git-ls-files -i --exclude-standard'
# command after changing this file, to see if there are
# any tracked files which get ignored after the change.
#
# Normal rules
#
.*
@@ -18,19 +22,21 @@
*.lst
*.symtypes
*.order
*.elf
*.bin
*.gz
#
# Top-level generic files
#
tags
TAGS
vmlinux*
!vmlinux.lds.S
!vmlinux.lds.h
vmlinux
System.map
Module.markers
Module.symvers
!.gitignore
!.mailmap
#
# Generated include files
CREDITS
+3 -2
View File
@@ -2611,8 +2611,9 @@ S: Perth, Western Australia
S: Australia
N: Miguel Ojeda Sandonis
E: maxextreme@gmail.com
W: http://maxextreme.googlepages.com/
E: miguel.ojeda.sandonis@gmail.com
W: http://miguelojeda.es
W: http://jair.lab.fi.uva.es/~migojed/
D: Author of the ks0108, cfag12864b and cfag12864bfb auxiliary display drivers.
D: Maintainer of the auxiliary display drivers tree (drivers/auxdisplay/*)
S: C/ Mieses 20, 9-B
Documentation/ABI/testing/sysfs-block
+34
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@@ -26,3 +26,37 @@ Description:
I/O statistics of partition <part>. The format is the
same as the above-written /sys/block/<disk>/stat
format.
What: /sys/block/<disk>/integrity/format
Date: June 2008
Contact: Martin K. Petersen <martin.petersen@oracle.com>
Description:
Metadata format for integrity capable block device.
E.g. T10-DIF-TYPE1-CRC.
What: /sys/block/<disk>/integrity/read_verify
Date: June 2008
Contact: Martin K. Petersen <martin.petersen@oracle.com>
Description:
Indicates whether the block layer should verify the
integrity of read requests serviced by devices that
support sending integrity metadata.
What: /sys/block/<disk>/integrity/tag_size
Date: June 2008
Contact: Martin K. Petersen <martin.petersen@oracle.com>
Description:
Number of bytes of integrity tag space available per
512 bytes of data.
What: /sys/block/<disk>/integrity/write_generate
Date: June 2008
Contact: Martin K. Petersen <martin.petersen@oracle.com>
Description:
Indicates whether the block layer should automatically
generate checksums for write requests bound for
devices that support receiving integrity metadata.
Documentation/ABI/testing/sysfs-bus-css
+35
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@@ -0,0 +1,35 @@
What: /sys/bus/css/devices/.../type
Date: March 2008
Contact: Cornelia Huck <cornelia.huck@de.ibm.com>
linux-s390@vger.kernel.org
Description: Contains the subchannel type, as reported by the hardware.
This attribute is present for all subchannel types.
What: /sys/bus/css/devices/.../modalias
Date: March 2008
Contact: Cornelia Huck <cornelia.huck@de.ibm.com>
linux-s390@vger.kernel.org
Description: Contains the module alias as reported with uevents.
It is of the format css:t<type> and present for all
subchannel types.
What: /sys/bus/css/drivers/io_subchannel/.../chpids
Date: December 2002
Contact: Cornelia Huck <cornelia.huck@de.ibm.com>
linux-s390@vger.kernel.org
Description: Contains the ids of the channel paths used by this
subchannel, as reported by the channel subsystem
during subchannel recognition.
Note: This is an I/O-subchannel specific attribute.
Users: s390-tools, HAL
What: /sys/bus/css/drivers/io_subchannel/.../pimpampom
Date: December 2002
Contact: Cornelia Huck <cornelia.huck@de.ibm.com>
linux-s390@vger.kernel.org
Description: Contains the PIM/PAM/POM values, as reported by the
channel subsystem when last queried by the common I/O
layer (this implies that this attribute is not neccessarily
in sync with the values current in the channel subsystem).
Note: This is an I/O-subchannel specific attribute.
Users: s390-tools, HAL
Documentation/ABI/testing/sysfs-firmware-memmap
+71
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@@ -0,0 +1,71 @@
What: /sys/firmware/memmap/
Date: June 2008
Contact: Bernhard Walle <bwalle@suse.de>
Description:
On all platforms, the firmware provides a memory map which the
kernel reads. The resources from that memory map are registered
in the kernel resource tree and exposed to userspace via
/proc/iomem (together with other resources).
However, on most architectures that firmware-provided memory
map is modified afterwards by the kernel itself, either because
the kernel merges that memory map with other information or
just because the user overwrites that memory map via command
line.
kexec needs the raw firmware-provided memory map to setup the
parameter segment of the kernel that should be booted with
kexec. Also, the raw memory map is useful for debugging. For
that reason, /sys/firmware/memmap is an interface that provides
the raw memory map to userspace.
The structure is as follows: Under /sys/firmware/memmap there
are subdirectories with the number of the entry as their name:
/sys/firmware/memmap/0
/sys/firmware/memmap/1
/sys/firmware/memmap/2
/sys/firmware/memmap/3
...
The maximum depends on the number of memory map entries provided
by the firmware. The order is just the order that the firmware
provides.
Each directory contains three files:
start : The start address (as hexadecimal number with the
'0x' prefix).
end : The end address, inclusive (regardless whether the
firmware provides inclusive or exclusive ranges).
type : Type of the entry as string. See below for a list of
valid types.
So, for example:
/sys/firmware/memmap/0/start
/sys/firmware/memmap/0/end
/sys/firmware/memmap/0/type
/sys/firmware/memmap/1/start
...
Currently following types exist:
- System RAM
- ACPI Tables
- ACPI Non-volatile Storage
- reserved
Following shell snippet can be used to display that memory
map in a human-readable format:
-------------------- 8< ----------------------------------------
#!/bin/bash
cd /sys/firmware/memmap
for dir in * ; do
start=$(cat $dir/start)
end=$(cat $dir/end)
type=$(cat $dir/type)
printf "%016x-%016x (%s)\n" $start $[ $end +1] "$type"
done
-------------------- >8 ----------------------------------------
Documentation/HOWTO
+1 -1
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@@ -377,7 +377,7 @@ Bug Reporting
bugzilla.kernel.org is where the Linux kernel developers track kernel
bugs. Users are encouraged to report all bugs that they find in this
tool. For details on how to use the kernel bugzilla, please see:
http://test.kernel.org/bugzilla/faq.html
http://bugzilla.kernel.org/page.cgi?id=faq.html
The file REPORTING-BUGS in the main kernel source directory has a good
template for how to report a possible kernel bug, and details what kind
Documentation/IRQ-affinity.txt
+29 -10
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@@ -1,17 +1,26 @@
ChangeLog:
Started by Ingo Molnar <mingo@redhat.com>
Update by Max Krasnyansky <maxk@qualcomm.com>
SMP IRQ affinity, started by Ingo Molnar <mingo@redhat.com>
SMP IRQ affinity
/proc/irq/IRQ#/smp_affinity specifies which target CPUs are permitted
for a given IRQ source. It's a bitmask of allowed CPUs. It's not allowed
to turn off all CPUs, and if an IRQ controller does not support IRQ
affinity then the value will not change from the default 0xffffffff.
Here is an example of restricting IRQ44 (eth1) to CPU0-3 then restricting
the IRQ to CPU4-7 (this is an 8-CPU SMP box):
/proc/irq/default_smp_affinity specifies default affinity mask that applies
to all non-active IRQs. Once IRQ is allocated/activated its affinity bitmask
will be set to the default mask. It can then be changed as described above.
Default mask is 0xffffffff.
Here is an example of restricting IRQ44 (eth1) to CPU0-3 then restricting
it to CPU4-7 (this is an 8-CPU SMP box):
[root@moon 44]# cd /proc/irq/44
[root@moon 44]# cat smp_affinity
ffffffff
[root@moon 44]# echo 0f > smp_affinity
[root@moon 44]# cat smp_affinity
0000000f
@@ -21,17 +30,27 @@ PING hell (195.4.7.3): 56 data bytes
--- hell ping statistics ---
6029 packets transmitted, 6027 packets received, 0% packet loss
round-trip min/avg/max = 0.1/0.1/0.4 ms
[root@moon 44]# cat /proc/interrupts | grep 44:
44: 0 1785 1785 1783 1783 1
1 0 IO-APIC-level eth1
[root@moon 44]# cat /proc/interrupts | grep 'CPU\|44:'
CPU0 CPU1 CPU2 CPU3 CPU4 CPU5 CPU6 CPU7
44: 1068 1785 1785 1783 0 0 0 0 IO-APIC-level eth1
As can be seen from the line above IRQ44 was delivered only to the first four
processors (0-3).
Now lets restrict that IRQ to CPU(4-7).
[root@moon 44]# echo f0 > smp_affinity
[root@moon 44]# cat smp_affinity
000000f0
[root@moon 44]# ping -f h
PING hell (195.4.7.3): 56 data bytes
..
--- hell ping statistics ---
2779 packets transmitted, 2777 packets received, 0% packet loss
round-trip min/avg/max = 0.1/0.5/585.4 ms
[root@moon 44]# cat /proc/interrupts | grep 44:
44: 1068 1785 1785 1784 1784 1069 1070 1069 IO-APIC-level eth1
[root@moon 44]#
[root@moon 44]# cat /proc/interrupts | 'CPU\|44:'
CPU0 CPU1 CPU2 CPU3 CPU4 CPU5 CPU6 CPU7
44: 1068 1785 1785 1783 1784 1069 1070 1069 IO-APIC-level eth1
This time around IRQ44 was delivered only to the last four processors.
i.e counters for the CPU0-3 did not change.
Documentation/accounting/taskstats-struct.txt
+6
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@@ -24,6 +24,8 @@ There are three different groups of fields in the struct taskstats:
4) Per-task and per-thread context switch count statistics
5) Time accounting for SMT machines
Future extension should add fields to the end of the taskstats struct, and
should not change the relative position of each field within the struct.
@@ -164,4 +166,8 @@ struct taskstats {
__u64 nvcsw; /* Context voluntary switch counter */
__u64 nivcsw; /* Context involuntary switch counter */
5) Time accounting for SMT machines
__u64 ac_utimescaled; /* utime scaled on frequency etc */
__u64 ac_stimescaled; /* stime scaled on frequency etc */
__u64 cpu_scaled_run_real_total; /* scaled cpu_run_real_total */
}
Documentation/auxdisplay/cfag12864b
+2 -2
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@@ -3,7 +3,7 @@
===================================
License: GPLv2
Author & Maintainer: Miguel Ojeda Sandonis <maxextreme@gmail.com>
Author & Maintainer: Miguel Ojeda Sandonis
Date: 2006-10-27
@@ -22,7 +22,7 @@ Date: 2006-10-27
1. DRIVER INFORMATION
---------------------
This driver support one cfag12864b display at time.
This driver supports a cfag12864b LCD.
---------------------
Documentation/auxdisplay/cfag12864b-example.c
+1 -1
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@@ -4,7 +4,7 @@
* Description: cfag12864b LCD userspace example program
* License: GPLv2
*
* Author: Copyright (C) Miguel Ojeda Sandonis <maxextreme@gmail.com>
* Author: Copyright (C) Miguel Ojeda Sandonis
* Date: 2006-10-31
*
* This program is free software; you can redistribute it and/or modify
Documentation/auxdisplay/ks0108
+2 -2
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@@ -3,7 +3,7 @@
==========================================
License: GPLv2
Author & Maintainer: Miguel Ojeda Sandonis <maxextreme@gmail.com>
Author & Maintainer: Miguel Ojeda Sandonis
Date: 2006-10-27
@@ -21,7 +21,7 @@ Date: 2006-10-27
1. DRIVER INFORMATION
---------------------
This driver support the ks0108 LCD controller.
This driver supports the ks0108 LCD controller.
---------------------
Documentation/block/data-integrity.txt
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@@ -0,0 +1,327 @@
----------------------------------------------------------------------
1. INTRODUCTION
Modern filesystems feature checksumming of data and metadata to
protect against data corruption. However, the detection of the
corruption is done at read time which could potentially be months
after the data was written. At that point the original data that the
application tried to write is most likely lost.
The solution is to ensure that the disk is actually storing what the
application meant it to. Recent additions to both the SCSI family
protocols (SBC Data Integrity Field, SCC protection proposal) as well
as SATA/T13 (External Path Protection) try to remedy this by adding
support for appending integrity metadata to an I/O. The integrity
metadata (or protection information in SCSI terminology) includes a
checksum for each sector as well as an incrementing counter that
ensures the individual sectors are written in the right order. And
for some protection schemes also that the I/O is written to the right
place on disk.
Current storage controllers and devices implement various protective
measures, for instance checksumming and scrubbing. But these
technologies are working in their own isolated domains or at best
between adjacent nodes in the I/O path. The interesting thing about
DIF and the other integrity extensions is that the protection format
is well defined and every node in the I/O path can verify the
integrity of the I/O and reject it if corruption is detected. This
allows not only corruption prevention but also isolation of the point
of failure.
----------------------------------------------------------------------
2. THE DATA INTEGRITY EXTENSIONS
As written, the protocol extensions only protect the path between
controller and storage device. However, many controllers actually
allow the operating system to interact with the integrity metadata
(IMD). We have been working with several FC/SAS HBA vendors to enable
the protection information to be transferred to and from their
controllers.
The SCSI Data Integrity Field works by appending 8 bytes of protection
information to each sector. The data + integrity metadata is stored
in 520 byte sectors on disk. Data + IMD are interleaved when
transferred between the controller and target. The T13 proposal is
similar.
Because it is highly inconvenient for operating systems to deal with
520 (and 4104) byte sectors, we approached several HBA vendors and
encouraged them to allow separation of the data and integrity metadata
scatter-gather lists.
The controller will interleave the buffers on write and split them on
read. This means that the Linux can DMA the data buffers to and from
host memory without changes to the page cache.
Also, the 16-bit CRC checksum mandated by both the SCSI and SATA specs
is somewhat heavy to compute in software. Benchmarks found that
calculating this checksum had a significant impact on system
performance for a number of workloads. Some controllers allow a
lighter-weight checksum to be used when interfacing with the operating
system. Emulex, for instance, supports the TCP/IP checksum instead.
The IP checksum received from the OS is converted to the 16-bit CRC
when writing and vice versa. This allows the integrity metadata to be
generated by Linux or the application at very low cost (comparable to
software RAID5).
The IP checksum is weaker than the CRC in terms of detecting bit
errors. However, the strength is really in the separation of the data
buffers and the integrity metadata. These two distinct buffers much
match up for an I/O to complete.
The separation of the data and integrity metadata buffers as well as
the choice in checksums is referred to as the Data Integrity
Extensions. As these extensions are outside the scope of the protocol
bodies (T10, T13), Oracle and its partners are trying to standardize
them within the Storage Networking Industry Association.
----------------------------------------------------------------------
3. KERNEL CHANGES
The data integrity framework in Linux enables protection information
to be pinned to I/Os and sent to/received from controllers that
support it.
The advantage to the integrity extensions in SCSI and SATA is that
they enable us to protect the entire path from application to storage
device. However, at the same time this is also the biggest
disadvantage. It means that the protection information must be in a
format that can be understood by the disk.
Generally Linux/POSIX applications are agnostic to the intricacies of
the storage devices they are accessing. The virtual filesystem switch
and the block layer make things like hardware sector size and
transport protocols completely transparent to the application.
However, this level of detail is required when preparing the
protection information to send to a disk. Consequently, the very
concept of an end-to-end protection scheme is a layering violation.
It is completely unreasonable for an application to be aware whether
it is accessing a SCSI or SATA disk.
The data integrity support implemented in Linux attempts to hide this
from the application. As far as the application (and to some extent
the kernel) is concerned, the integrity metadata is opaque information
that's attached to the I/O.
The current implementation allows the block layer to automatically
generate the protection information for any I/O. Eventually the
intent is to move the integrity metadata calculation to userspace for
user data. Metadata and other I/O that originates within the kernel
will still use the automatic generation interface.
Some storage devices allow each hardware sector to be tagged with a
16-bit value. The owner of this tag space is the owner of the block
device. I.e. the filesystem in most cases. The filesystem can use
this extra space to tag sectors as they see fit. Because the tag
space is limited, the block interface allows tagging bigger chunks by
way of interleaving. This way, 8*16 bits of information can be
attached to a typical 4KB filesystem block.
This also means that applications such as fsck and mkfs will need
access to manipulate the tags from user space. A passthrough
interface for this is being worked on.
----------------------------------------------------------------------
4. BLOCK LAYER IMPLEMENTATION DETAILS
4.1 BIO
The data integrity patches add a new field to struct bio when
CONFIG_BLK_DEV_INTEGRITY is enabled. bio->bi_integrity is a pointer
to a struct bip which contains the bio integrity payload. Essentially
a bip is a trimmed down struct bio which holds a bio_vec containing
the integrity metadata and the required housekeeping information (bvec
pool, vector count, etc.)
A kernel subsystem can enable data integrity protection on a bio by
calling bio_integrity_alloc(bio). This will allocate and attach the
bip to the bio.
Individual pages containing integrity metadata can subsequently be
attached using bio_integrity_add_page().
bio_free() will automatically free the bip.
4.2 BLOCK DEVICE
Because the format of the protection data is tied to the physical
disk, each block device has been extended with a block integrity
profile (struct blk_integrity). This optional profile is registered
with the block layer using blk_integrity_register().
The profile contains callback functions for generating and verifying
the protection data, as well as getting and setting application tags.
The profile also contains a few constants to aid in completing,
merging and splitting the integrity metadata.
Layered block devices will need to pick a profile that's appropriate
for all subdevices. blk_integrity_compare() can help with that. DM
and MD linear, RAID0 and RAID1 are currently supported. RAID4/5/6
will require extra work due to the application tag.
----------------------------------------------------------------------
5.0 BLOCK LAYER INTEGRITY API
5.1 NORMAL FILESYSTEM
The normal filesystem is unaware that the underlying block device
is capable of sending/receiving integrity metadata. The IMD will
be automatically generated by the block layer at submit_bio() time
in case of a WRITE. A READ request will cause the I/O integrity
to be verified upon completion.
IMD generation and verification can be toggled using the
/sys/block/<bdev>/integrity/write_generate
and
/sys/block/<bdev>/integrity/read_verify
flags.
5.2 INTEGRITY-AWARE FILESYSTEM
A filesystem that is integrity-aware can prepare I/Os with IMD
attached. It can also use the application tag space if this is
supported by the block device.
int bdev_integrity_enabled(block_device, int rw);
bdev_integrity_enabled() will return 1 if the block device
supports integrity metadata transfer for the data direction
specified in 'rw'.
bdev_integrity_enabled() honors the write_generate and
read_verify flags in sysfs and will respond accordingly.
int bio_integrity_prep(bio);
To generate IMD for WRITE and to set up buffers for READ, the
filesystem must call bio_integrity_prep(bio).
Prior to calling this function, the bio data direction and start
sector must be set, and the bio should have all data pages
added. It is up to the caller to ensure that the bio does not
change while I/O is in progress.
bio_integrity_prep() should only be called if
bio_integrity_enabled() returned 1.
int bio_integrity_tag_size(bio);
If the filesystem wants to use the application tag space it will
first have to find out how much storage space is available.
Because tag space is generally limited (usually 2 bytes per
sector regardless of sector size), the integrity framework
supports interleaving the information between the sectors in an
I/O.
Filesystems can call bio_integrity_tag_size(bio) to find out how
many bytes of storage are available for that particular bio.
Another option is bdev_get_tag_size(block_device) which will
return the number of available bytes per hardware sector.
int bio_integrity_set_tag(bio, void *tag_buf, len);
After a successful return from bio_integrity_prep(),
bio_integrity_set_tag() can be used to attach an opaque tag
buffer to a bio. Obviously this only makes sense if the I/O is
a WRITE.
int bio_integrity_get_tag(bio, void *tag_buf, len);
Similarly, at READ I/O completion time the filesystem can
retrieve the tag buffer using bio_integrity_get_tag().
6.3 PASSING EXISTING INTEGRITY METADATA
Filesystems that either generate their own integrity metadata or
are capable of transferring IMD from user space can use the
following calls:
struct bip * bio_integrity_alloc(bio, gfp_mask, nr_pages);
Allocates the bio integrity payload and hangs it off of the bio.
nr_pages indicate how many pages of protection data need to be
stored in the integrity bio_vec list (similar to bio_alloc()).
The integrity payload will be freed at bio_free() time.
int bio_integrity_add_page(bio, page, len, offset);
Attaches a page containing integrity metadata to an existing
bio. The bio must have an existing bip,
i.e. bio_integrity_alloc() must have been called. For a WRITE,
the integrity metadata in the pages must be in a format
understood by the target device with the notable exception that
the sector numbers will be remapped as the request traverses the
I/O stack. This implies that the pages added using this call
will be modified during I/O! The first reference tag in the
integrity metadata must have a value of bip->bip_sector.
Pages can be added using bio_integrity_add_page() as long as
there is room in the bip bio_vec array (nr_pages).
Upon completion of a READ operation, the attached pages will
contain the integrity metadata received from the storage device.
It is up to the receiver to process them and verify data
integrity upon completion.
6.4 REGISTERING A BLOCK DEVICE AS CAPABLE OF EXCHANGING INTEGRITY
METADATA
To enable integrity exchange on a block device the gendisk must be
registered as capable:
int blk_integrity_register(gendisk, blk_integrity);
The blk_integrity struct is a template and should contain the
following:
static struct blk_integrity my_profile = {
.name = "STANDARDSBODY-TYPE-VARIANT-CSUM",
.generate_fn = my_generate_fn,
.verify_fn = my_verify_fn,
.get_tag_fn = my_get_tag_fn,
.set_tag_fn = my_set_tag_fn,
.tuple_size = sizeof(struct my_tuple_size),
.tag_size = <tag bytes per hw sector>,
};
'name' is a text string which will be visible in sysfs. This is
part of the userland API so chose it carefully and never change
it. The format is standards body-type-variant.
E.g. T10-DIF-TYPE1-IP or T13-EPP-0-CRC.
'generate_fn' generates appropriate integrity metadata (for WRITE).
'verify_fn' verifies that the data buffer matches the integrity
metadata.
'tuple_size' must be set to match the size of the integrity
metadata per sector. I.e. 8 for DIF and EPP.
'tag_size' must be set to identify how many bytes of tag space
are available per hardware sector. For DIF this is either 2 or
0 depending on the value of the Control Mode Page ATO bit.
See 6.2 for a description of get_tag_fn and set_tag_fn.
----------------------------------------------------------------------
2007-12-24 Martin K. Petersen <martin.petersen@oracle.com>
Documentation/cgroups.txt
+4
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@@ -390,6 +390,10 @@ If you have several tasks to attach, you have to do it one after another:
...
# /bin/echo PIDn > tasks
You can attach the current shell task by echoing 0:
# echo 0 > tasks
3. Kernel API
=============
Documentation/controllers/devices.txt
+6 -2
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@@ -13,7 +13,7 @@ either an integer or * for all. Access is a composition of r
The root device cgroup starts with rwm to 'all'. A child device
cgroup gets a copy of the parent. Administrators can then remove
devices from the whitelist or add new entries. A child cgroup can
never receive a device access which is denied its parent. However
never receive a device access which is denied by its parent. However
when a device access is removed from a parent it will not also be
removed from the child(ren).
@@ -29,7 +29,11 @@ allows cgroup 1 to read and mknod the device usually known as
echo a > /cgroups/1/devices.deny
will remove the default 'a *:* mrw' entry.
will remove the default 'a *:* rwm' entry. Doing
echo a > /cgroups/1/devices.allow
will add the 'a *:* rwm' entry to the whitelist.
3. Security
Documentation/cpusets.txt
+7 -2
View File
@@ -154,13 +154,15 @@ browsing and modifying the cpusets presently known to the kernel. No
new system calls are added for cpusets - all support for querying and
modifying cpusets is via this cpuset file system.
The /proc/<pid>/status file for each task has two added lines,
The /proc/<pid>/status file for each task has four added lines,
displaying the tasks cpus_allowed (on which CPUs it may be scheduled)
and mems_allowed (on which Memory Nodes it may obtain memory),
in the format seen in the following example:
in the two formats seen in the following example:
Cpus_allowed: ffffffff,ffffffff,ffffffff,ffffffff
Cpus_allowed_list: 0-127
Mems_allowed: ffffffff,ffffffff
Mems_allowed_list: 0-63
Each cpuset is represented by a directory in the cgroup file system
containing (on top of the standard cgroup files) the following
@@ -544,6 +546,9 @@ otherwise initial value -1 that indicates the cpuset has no request.
( 4 : search nodes in a chunk of node [on NUMA system] )
( 5 : search system wide [on NUMA system] )
The system default is architecture dependent. The system default
can be changed using the relax_domain_level= boot parameter.
This file is per-cpuset and affect the sched domain where the cpuset
belongs to. Therefore if the flag 'sched_load_balance' of a cpuset
is disabled, then 'sched_relax_domain_level' have no effect since
Documentation/cputopology.txt
+9 -17
View File
@@ -14,9 +14,8 @@ represent the thread siblings to cpu X in the same physical package;
To implement it in an architecture-neutral way, a new source file,
drivers/base/topology.c, is to export the 4 attributes.
If one architecture wants to support this feature, it just needs to
implement 4 defines, typically in file include/asm-XXX/topology.h.
The 4 defines are:
For an architecture to support this feature, it must define some of
these macros in include/asm-XXX/topology.h:
#define topology_physical_package_id(cpu)
#define topology_core_id(cpu)
#define topology_thread_siblings(cpu)
@@ -25,17 +24,10 @@ The 4 defines are:
The type of **_id is int.
The type of siblings is cpumask_t.
To be consistent on all architectures, the 4 attributes should have
default values if their values are unavailable. Below is the rule.
1) physical_package_id: If cpu has no physical package id, -1 is the
default value.
2) core_id: If cpu doesn't support multi-core, its core id is 0.
3) thread_siblings: Just include itself, if the cpu doesn't support
HT/multi-thread.
4) core_siblings: Just include itself, if the cpu doesn't support
multi-core and HT/Multi-thread.
So be careful when declaring the 4 defines in include/asm-XXX/topology.h.
If an attribute isn't defined on an architecture, it won't be exported.
To be consistent on all architectures, include/linux/topology.h
provides default definitions for any of the above macros that are
not defined by include/asm-XXX/topology.h:
1) physical_package_id: -1
2) core_id: 0
3) thread_siblings: just the given CPU
4) core_siblings: just the given CPU
Documentation/feature-removal-schedule.txt
+9 -7
View File
@@ -222,13 +222,6 @@ Who: Thomas Gleixner <tglx@linutronix.de>
---------------------------
What: i2c-i810, i2c-prosavage and i2c-savage4
When: May 2008
Why: These drivers are superseded by i810fb, intelfb and savagefb.
Who: Jean Delvare <khali@linux-fr.org>
---------------------------
What (Why):
- include/linux/netfilter_ipv4/ipt_TOS.h ipt_tos.h header files
(superseded by xt_TOS/xt_tos target & match)
@@ -312,3 +305,12 @@ When: 2.6.26
Why: Implementation became generic; users should now include
linux/semaphore.h instead.
Who: Matthew Wilcox <willy@linux.intel.com>
---------------------------
What: CONFIG_THERMAL_HWMON
When: January 2009
Why: This option was introduced just to allow older lm-sensors userspace
to keep working over the upgrade to 2.6.26. At the scheduled time of
removal fixed lm-sensors (2.x or 3.x) should be readily available.
Who: Rene Herman <rene.herman@gmail.com>
Documentation/filesystems/ext4.txt
+75 -50
View File
@@ -13,72 +13,93 @@ Mailing list: linux-ext4@vger.kernel.org
1. Quick usage instructions:
===========================
- Grab updated e2fsprogs from
ftp://ftp.kernel.org/pub/linux/kernel/people/tytso/e2fsprogs-interim/
This is a patchset on top of e2fsprogs-1.39, which can be found at
- Compile and install the latest version of e2fsprogs (as of this
writing version 1.41) from:
http://sourceforge.net/project/showfiles.php?group_id=2406
or
ftp://ftp.kernel.org/pub/linux/kernel/people/tytso/e2fsprogs/
- It's still mke2fs -j /dev/hda1
or grab the latest git repository from:
- mount /dev/hda1 /wherever -t ext4dev
git://git.kernel.org/pub/scm/fs/ext2/e2fsprogs.git
- To enable extents,
- Create a new filesystem using the ext4dev filesystem type:
mount /dev/hda1 /wherever -t ext4dev -o extents
# mke2fs -t ext4dev /dev/hda1
- The filesystem is compatible with the ext3 driver until you add a file
which has extents (ie: `mount -o extents', then create a file).
Or configure an existing ext3 filesystem to support extents and set
the test_fs flag to indicate that it's ok for an in-development
filesystem to touch this filesystem:
NOTE: The "extents" mount flag is temporary. It will soon go away and
extents will be enabled by the "-o extents" flag to mke2fs or tune2fs
# tune2fs -O extents -E test_fs /dev/hda1
If the filesystem was created with 128 byte inodes, it can be
converted to use 256 byte for greater efficiency via:
# tune2fs -I 256 /dev/hda1
(Note: we currently do not have tools to convert an ext4dev
filesystem back to ext3; so please do not do try this on production
filesystems.)
- Mounting:
# mount -t ext4dev /dev/hda1 /wherever
- When comparing performance with other filesystems, remember that
ext3/4 by default offers higher data integrity guarantees than most. So
when comparing with a metadata-only journalling filesystem, use `mount -o
data=writeback'. And you might as well use `mount -o nobh' too along
with it. Making the journal larger than the mke2fs default often helps
performance with metadata-intensive workloads.
ext3/4 by default offers higher data integrity guarantees than most.
So when comparing with a metadata-only journalling filesystem, such
as ext3, use `mount -o data=writeback'. And you might as well use
`mount -o nobh' too along with it. Making the journal larger than
the mke2fs default often helps performance with metadata-intensive
workloads.
2. Features
===========
2.1 Currently available
* ability to use filesystems > 16TB
* ability to use filesystems > 16TB (e2fsprogs support not available yet)
* extent format reduces metadata overhead (RAM, IO for access, transactions)
* extent format more robust in face of on-disk corruption due to magics,
* internal redunancy in tree
2.1 Previously available, soon to be enabled by default by "mkefs.ext4":
* dir_index and resize inode will be on by default
* large inodes will be used by default for fast EAs, nsec timestamps, etc
* improved file allocation (multi-block alloc)
* fix 32000 subdirectory limit
* nsec timestamps for mtime, atime, ctime, create time
* inode version field on disk (NFSv4, Lustre)
* reduced e2fsck time via uninit_bg feature
* journal checksumming for robustness, performance
* persistent file preallocation (e.g for streaming media, databases)
* ability to pack bitmaps and inode tables into larger virtual groups via the
flex_bg feature
* large file support
* Inode allocation using large virtual block groups via flex_bg
* delayed allocation
* large block (up to pagesize) support
* efficent new ordered mode in JBD2 and ext4(avoid using buffer head to force
the ordering)
2.2 Candidate features for future inclusion
There are several under discussion, whether they all make it in is
partly a function of how much time everyone has to work on them:
* Online defrag (patches available but not well tested)
* reduced mke2fs time via lazy itable initialization in conjuction with
the uninit_bg feature (capability to do this is available in e2fsprogs
but a kernel thread to do lazy zeroing of unused inode table blocks
after filesystem is first mounted is required for safety)
* improved file allocation (multi-block alloc, delayed alloc; basically done)
* fix 32000 subdirectory limit (patch exists, needs some e2fsck work)
* nsec timestamps for mtime, atime, ctime, create time (patch exists,
needs some e2fsck work)
* inode version field on disk (NFSv4, Lustre; prototype exists)
* reduced mke2fs/e2fsck time via uninitialized groups (prototype exists)
* journal checksumming for robustness, performance (prototype exists)
* persistent file preallocation (e.g for streaming media, databases)
There are several others under discussion, whether they all make it in is
partly a function of how much time everyone has to work on them. Features like
metadata checksumming have been discussed and planned for a bit but no patches
exist yet so I'm not sure they're in the near-term roadmap.
Features like metadata checksumming have been discussed and planned for
a bit but no patches exist yet so I'm not sure they're in the near-term
roadmap.
The big performance win will come with mballoc, delalloc and flex_bg
grouping of bitmaps and inode tables. Some test results available here:
The big performance win will come with mballoc and delalloc. CFS has
been using mballoc for a few years already with Lustre, and IBM + Bull
did a lot of benchmarking on it. The reason it isn't in the first set of
patches is partly a manageability issue, and partly because it doesn't
directly affect the on-disk format (outside of much better allocation)
so it isn't critical to get into the first round of changes. I believe
Alex is working on a new set of patches right now.
- http://www.bullopensource.org/ext4/20080530/ffsb-write-2.6.26-rc2.html
- http://www.bullopensource.org/ext4/20080530/ffsb-readwrite-2.6.26-rc2.html
3. Options
==========
@@ -222,9 +243,11 @@ stripe=n Number of filesystem blocks that mballoc will try
to use for allocation size and alignment. For RAID5/6
systems this should be the number of data
disks * RAID chunk size in file system blocks.
delalloc (*) Deferring block allocation until write-out time.
nodelalloc Disable delayed allocation. Blocks are allocation
when data is copied from user to page cache.
Data Mode
---------
=========
There are 3 different data modes:
* writeback mode
@@ -236,10 +259,10 @@ typically provide the best ext4 performance.
* ordered mode
In data=ordered mode, ext4 only officially journals metadata, but it logically
groups metadata and data blocks into a single unit called a transaction. When
it's time to write the new metadata out to disk, the associated data blocks
are written first. In general, this mode performs slightly slower than
writeback but significantly faster than journal mode.
groups metadata information related to data changes with the data blocks into a
single unit called a transaction. When it's time to write the new metadata
out to disk, the associated data blocks are written first. In general,
this mode performs slightly slower than writeback but significantly faster than journal mode.
* journal mode
data=journal mode provides full data and metadata journaling. All new data is
@@ -247,7 +270,8 @@ written to the journal first, and then to its final location.
In the event of a crash, the journal can be replayed, bringing both data and
metadata into a consistent state. This mode is the slowest except when data
needs to be read from and written to disk at the same time where it
outperforms all others modes.
outperforms all others modes. Curently ext4 does not have delayed
allocation support if this data journalling mode is selected.
References
==========
@@ -256,7 +280,8 @@ kernel source: <file:fs/ext4/>
<file:fs/jbd2/>
programs: http://e2fsprogs.sourceforge.net/
http://ext2resize.sourceforge.net
useful links: http://fedoraproject.org/wiki/ext3-devel
http://www.bullopensource.org/ext4/
http://ext4.wiki.kernel.org/index.php/Main_Page
http://fedoraproject.org/wiki/Features/Ext4
Documentation/filesystems/gfs2-glocks.txt
+114
View File
@@ -0,0 +1,114 @@
Glock internal locking rules
------------------------------
This documents the basic principles of the glock state machine
internals. Each glock (struct gfs2_glock in fs/gfs2/incore.h)
has two main (internal) locks:
1. A spinlock (gl_spin) which protects the internal state such
as gl_state, gl_target and the list of holders (gl_holders)
2. A non-blocking bit lock, GLF_LOCK, which is used to prevent other
threads from making calls to the DLM, etc. at the same time. If a
thread takes this lock, it must then call run_queue (usually via the
workqueue) when it releases it in order to ensure any pending tasks
are completed.
The gl_holders list contains all the queued lock requests (not
just the holders) associated with the glock. If there are any
held locks, then they will be contiguous entries at the head
of the list. Locks are granted in strictly the order that they
are queued, except for those marked LM_FLAG_PRIORITY which are
used only during recovery, and even then only for journal locks.
There are three lock states that users of the glock layer can request,
namely shared (SH), deferred (DF) and exclusive (EX). Those translate
to the following DLM lock modes:
Glock mode | DLM lock mode
------------------------------
UN | IV/NL Unlocked (no DLM lock associated with glock) or NL
SH | PR (Protected read)
DF | CW (Concurrent write)
EX | EX (Exclusive)
Thus DF is basically a shared mode which is incompatible with the "normal"
shared lock mode, SH. In GFS2 the DF mode is used exclusively for direct I/O
operations. The glocks are basically a lock plus some routines which deal
with cache management. The following rules apply for the cache:
Glock mode | Cache data | Cache Metadata | Dirty Data | Dirty Metadata
--------------------------------------------------------------------------
UN | No | No | No | No
SH | Yes | Yes | No | No
DF | No | Yes | No | No
EX | Yes | Yes | Yes | Yes
These rules are implemented using the various glock operations which
are defined for each type of glock. Not all types of glocks use
all the modes. Only inode glocks use the DF mode for example.
Table of glock operations and per type constants:
Field | Purpose
----------------------------------------------------------------------------
go_xmote_th | Called before remote state change (e.g. to sync dirty data)
go_xmote_bh | Called after remote state change (e.g. to refill cache)
go_inval | Called if remote state change requires invalidating the cache
go_demote_ok | Returns boolean value of whether its ok to demote a glock
| (e.g. checks timeout, and that there is no cached data)
go_lock | Called for the first local holder of a lock
go_unlock | Called on the final local unlock of a lock
go_dump | Called to print content of object for debugfs file, or on
| error to dump glock to the log.
go_type; | The type of the glock, LM_TYPE_.....
go_min_hold_time | The minimum hold time
The minimum hold time for each lock is the time after a remote lock
grant for which we ignore remote demote requests. This is in order to
prevent a situation where locks are being bounced around the cluster
from node to node with none of the nodes making any progress. This
tends to show up most with shared mmaped files which are being written
to by multiple nodes. By delaying the demotion in response to a
remote callback, that gives the userspace program time to make
some progress before the pages are unmapped.
There is a plan to try and remove the go_lock and go_unlock callbacks
if possible, in order to try and speed up the fast path though the locking.
Also, eventually we hope to make the glock "EX" mode locally shared
such that any local locking will be done with the i_mutex as required
rather than via the glock.
Locking rules for glock operations:
Operation | GLF_LOCK bit lock held | gl_spin spinlock held
-----------------------------------------------------------------
go_xmote_th | Yes | No
go_xmote_bh | Yes | No
go_inval | Yes | No
go_demote_ok | Sometimes | Yes
go_lock | Yes | No
go_unlock | Yes | No
go_dump | Sometimes | Yes
N.B. Operations must not drop either the bit lock or the spinlock
if its held on entry. go_dump and do_demote_ok must never block.
Note that go_dump will only be called if the glock's state
indicates that it is caching uptodate data.
Glock locking order within GFS2:
1. i_mutex (if required)
2. Rename glock (for rename only)
3. Inode glock(s)
(Parents before children, inodes at "same level" with same parent in
lock number order)
4. Rgrp glock(s) (for (de)allocation operations)
5. Transaction glock (via gfs2_trans_begin) for non-read operations
6. Page lock (always last, very important!)
There are two glocks per inode. One deals with access to the inode
itself (locking order as above), and the other, known as the iopen
glock is used in conjunction with the i_nlink field in the inode to
determine the lifetime of the inode in question. Locking of inodes
is on a per-inode basis. Locking of rgrps is on a per rgrp basis.
Documentation/filesystems/proc.txt
+18 -11
View File
@@ -380,28 +380,35 @@ i386 and x86_64 platforms support the new IRQ vector displays.
Of some interest is the introduction of the /proc/irq directory to 2.4.
It could be used to set IRQ to CPU affinity, this means that you can "hook" an
IRQ to only one CPU, or to exclude a CPU of handling IRQs. The contents of the
irq subdir is one subdir for each IRQ, and one file; prof_cpu_mask
irq subdir is one subdir for each IRQ, and two files; default_smp_affinity and
prof_cpu_mask.
For example
> ls /proc/irq/
0 10 12 14 16 18 2 4 6 8 prof_cpu_mask
1 11 13 15 17 19 3 5 7 9
1 11 13 15 17 19 3 5 7 9 default_smp_affinity
> ls /proc/irq/0/
smp_affinity
The contents of the prof_cpu_mask file and each smp_affinity file for each IRQ
is the same by default:
smp_affinity is a bitmask, in which you can specify which CPUs can handle the
IRQ, you can set it by doing:
> cat /proc/irq/0/smp_affinity
> echo 1 > /proc/irq/10/smp_affinity
This means that only the first CPU will handle the IRQ, but you can also echo
5 which means that only the first and fourth CPU can handle the IRQ.
The contents of each smp_affinity file is the same by default:
> cat /proc/irq/0/smp_affinity
ffffffff
It's a bitmask, in which you can specify which CPUs can handle the IRQ, you can
set it by doing:
The default_smp_affinity mask applies to all non-active IRQs, which are the
IRQs which have not yet been allocated/activated, and hence which lack a
/proc/irq/[0-9]* directory.
> echo 1 > /proc/irq/prof_cpu_mask
This means that only the first CPU will handle the IRQ, but you can also echo 5
which means that only the first and fourth CPU can handle the IRQ.
prof_cpu_mask specifies which CPUs are to be profiled by the system wide
profiler. Default value is ffffffff (all cpus).
The way IRQs are routed is handled by the IO-APIC, and it's Round Robin
between all the CPUs which are allowed to handle it. As usual the kernel has

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