*** This bug is a duplicate of bug 418509 ***
https://bugs.launchpad.net/bugs/418509
Found some further changes in the kernel update:
diff -Nru /tmp/FNdEZPHKHo/linux-2.6.31/Documentation/filesystems/afs.txt
/tmp/Td2i4nRkP9/linux-2.6.31/Documentation/filesystems/afs.txt
--- linux-2.6.31/Documentation/filesystems/afs.txt 2009-08-21
18:39:55.000000000 +0100
+++ linux-2.6.31/Documentation/filesystems/afs.txt 2009-08-24
18:08:31.000000000 +0100
@@ -23,15 +23,13 @@
(*) Security (currently only AFS kaserver and KerberosIV tickets).
- (*) File reading.
+ (*) File reading and writing.
(*) Automounting.
-It does not yet support the following AFS features:
-
- (*) Write support.
+ (*) Local caching (via fscache).
- (*) Local caching.
+It does not yet support the following AFS features:
(*) pioctl() system call.
@@ -56,7 +54,7 @@
the masks in the following files:
/sys/module/af_rxrpc/parameters/debug
- /sys/module/afs/parameters/debug
+ /sys/module/kafs/parameters/debug
=====
@@ -66,9 +64,9 @@
When inserting the driver modules the root cell must be specified along with a
list of volume location server IP addresses:
- insmod af_rxrpc.o
- insmod rxkad.o
- insmod kafs.o rootcell=cambridge.redhat.com:172.16.18.73:172.16.18.91
+ modprobe af_rxrpc
+ modprobe rxkad
+ modprobe kafs rootcell=cambridge.redhat.com:172.16.18.73:172.16.18.91
The first module is the AF_RXRPC network protocol driver. This provides the
RxRPC remote operation protocol and may also be accessed from userspace. See:
@@ -81,7 +79,7 @@
Once the module has been loaded, more modules can be added by the following
procedure:
- echo add grand.central.org 18.7.14.88:128.2.191.224 >/proc/fs/afs/cells
+ echo add grand.central.org 18.9.48.14:128.2.203.61:130.237.48.87
>/proc/fs/afs/cells
Where the parameters to the "add" command are the name of a cell and a list of
volume location servers within that cell, with the latter separated by colons.
@@ -101,7 +99,7 @@
specify connection to only volumes of those types.
The name of the cell is optional, and if not given during a mount, then the
-named volume will be looked up in the cell specified during insmod.
+named volume will be looked up in the cell specified during modprobe.
Additional cells can be added through /proc (see later section).
@@ -163,14 +161,14 @@
The filesystem maintains an internal database of all the cells it knows and the
IP addresses of the volume location servers for those cells. The cell to which
-the system belongs is added to the database when insmod is performed by the
+the system belongs is added to the database when modprobe is performed by the
"rootcell=" argument or, if compiled in, using a "kafs.rootcell=" argument on
the kernel command line.
Further cells can be added by commands similar to the following:
echo add CELLNAME VLADDR[:VLADDR][:VLADDR]... >/proc/fs/afs/cells
- echo add grand.central.org 18.7.14.88:128.2.191.224 >/proc/fs/afs/cells
+ echo add grand.central.org 18.9.48.14:128.2.203.61:130.237.48.87
>/proc/fs/afs/cells
No other cell database operations are available at this time.
@@ -233,7 +231,7 @@
mount -t afs \%root.afs. /afs
mount -t afs \%cambridge.redhat.com:root.cell. /afs/cambridge.redhat.com/
-echo add grand.central.org 18.7.14.88:128.2.191.224 > /proc/fs/afs/cells
+echo add grand.central.org 18.9.48.14:128.2.203.61:130.237.48.87 >
/proc/fs/afs/cells
mount -t afs "#grand.central.org:root.cell." /afs/grand.central.org/
mount -t afs "#grand.central.org:root.archive." /afs/grand.central.org/archive
mount -t afs "#grand.central.org:root.contrib." /afs/grand.central.org/contrib
----------------------------------------------------------------------------------------------------
diff -Nru /tmp/FNdEZPHKHo/linux-2.6.31/Documentation/filesystems/proc.txt
/tmp/Td2i4nRkP9/linux-2.6.31/Documentation/filesystems/proc.txt
--- linux-2.6.31/Documentation/filesystems/proc.txt 2009-08-21
18:39:55.000000000 +0100
+++ linux-2.6.31/Documentation/filesystems/proc.txt 2009-08-24
18:08:31.000000000 +0100
@@ -1167,13 +1167,11 @@
3.1 /proc/<pid>/oom_adj - Adjust the oom-killer score
------------------------------------------------------
-This file can be used to adjust the score used to select which processes should
-be killed in an out-of-memory situation. The oom_adj value is a characteristic
-of the task's mm, so all threads that share an mm with pid will have the same
-oom_adj value. A high value will increase the likelihood of this process being
-killed by the oom-killer. Valid values are in the range -16 to +15 as
-explained below and a special value of -17, which disables oom-killing
-altogether for threads sharing pid's mm.
+This file can be used to adjust the score used to select which processes
+should be killed in an out-of-memory situation. Giving it a high score will
+increase the likelihood of this process being killed by the oom-killer. Valid
+values are in the range -16 to +15, plus the special value -17, which disables
+oom-killing altogether for this process.
The process to be killed in an out-of-memory situation is selected among all
others
based on its badness score. This value equals the original memory size of the
process
@@ -1187,9 +1185,6 @@
are the prime candidates to be killed. Having only one 'hungry' child will make
parent less preferable than the child.
-/proc/<pid>/oom_adj cannot be changed for kthreads since they are immune from
-oom-killing already.
-
/proc/<pid>/oom_score shows process' current badness score.
The following heuristics are then applied:
(nothing listed here?)
-----------------------------------------------------------------------------------------------------------
diff -Nru /tmp/FNdEZPHKHo/linux-2.6.31/Documentation/vm/00-INDEX
/tmp/Td2i4nRkP9/linux-2.6.31/Documentation/vm/00-INDEX
--- linux-2.6.31/Documentation/vm/00-INDEX 2009-08-21 18:39:55.000000000
+0100
+++ linux-2.6.31/Documentation/vm/00-INDEX 2009-08-24 18:08:31.000000000
+0100
@@ -6,6 +6,8 @@
- various information on memory balancing.
hugetlbpage.txt
- a brief summary of hugetlbpage support in the Linux kernel.
+ksm.txt
+ - how to use the Kernel Samepage Merging feature.
locking
- info on how locking and synchronization is done in the Linux vm code.
numa
-----------------------------------------------------------------------------------
diff -Nru /tmp/FNdEZPHKHo/linux-2.6.31/Documentation/vm/ksm.txt
/tmp/Td2i4nRkP9/linux-2.6.31/Documentation/vm/ksm.txt
--- linux-2.6.31/Documentation/vm/ksm.txt 1970-01-01 01:00:00.000000000
+0100
+++ linux-2.6.31/Documentation/vm/ksm.txt 2009-08-24 18:08:31.000000000
+0100
@@ -0,0 +1,89 @@
+How to use the Kernel Samepage Merging feature
+----------------------------------------------
+
+KSM is a memory-saving de-duplication feature, enabled by CONFIG_KSM=y,
+added to the Linux kernel in 2.6.32. See mm/ksm.c for its implementation,
+and http://lwn.net/Articles/306704/ and http://lwn.net/Articles/330589/
+
+The KSM daemon ksmd periodically scans those areas of user memory which
+have been registered with it, looking for pages of identical content which
+can be replaced by a single write-protected page (which is automatically
+copied if a process later wants to update its content).
+
+KSM was originally developed for use with KVM (where it was known as
+Kernel Shared Memory), to fit more virtual machines into physical memory,
+by sharing the data common between them. But it can be useful to any
+application which generates many instances of the same data.
+
+KSM only merges anonymous (private) pages, never pagecache (file) pages.
+KSM's merged pages are at present locked into kernel memory for as long
+as they are shared: so cannot be swapped out like the user pages they
+replace (but swapping KSM pages should follow soon in a later release).
+
+KSM only operates on those areas of address space which an application
+has advised to be likely candidates for merging, by using the madvise(2)
+system call: int madvise(addr, length, MADV_MERGEABLE).
+
+The app may call int madvise(addr, length, MADV_UNMERGEABLE) to cancel
+that advice and restore unshared pages: whereupon KSM unmerges whatever
+it merged in that range. Note: this unmerging call may suddenly require
+more memory than is available - possibly failing with EAGAIN, but more
+probably arousing the Out-Of-Memory killer.
+
+If KSM is not configured into the running kernel, madvise MADV_MERGEABLE
+and MADV_UNMERGEABLE simply fail with EINVAL. If the running kernel was
+built with CONFIG_KSM=y, those calls will normally succeed: even if the
+the KSM daemon is not currently running, MADV_MERGEABLE still registers
+the range for whenever the KSM daemon is started; even if the range
+cannot contain any pages which KSM could actually merge; even if
+MADV_UNMERGEABLE is applied to a range which was never MADV_MERGEABLE.
+
+Like other madvise calls, they are intended for use on mapped areas of
+the user address space: they will report ENOMEM if the specified range
+includes unmapped gaps (though working on the intervening mapped areas),
+and might fail with EAGAIN if not enough memory for internal structures.
+
+Applications should be considerate in their use of MADV_MERGEABLE,
+restricting its use to areas likely to benefit. KSM's scans may use
+a lot of processing power, and its kernel-resident pages are a limited
+resource. Some installations will disable KSM for these reasons.
+
+The KSM daemon is controlled by sysfs files in /sys/kernel/mm/ksm/,
+readable by all but writable only by root:
+max_kernel_pages - set to maximum number of kernel pages that KSM may use
+ e.g. "echo 2000 > /sys/kernel/mm/ksm/max_kernel_pages"
+ Value 0 imposes no limit on the kernel pages KSM may use;
+ but note that any process using MADV_MERGEABLE can cause
+ KSM to allocate these pages, unswappable until it exits.
+ Default: 2000 (chosen for demonstration purposes)
+
+pages_to_scan - how many present pages to scan before ksmd goes to sleep
+ e.g. "echo 200 > /sys/kernel/mm/ksm/pages_to_scan"
+ Default: 200 (chosen for demonstration purposes)
+
+sleep_millisecs - how many milliseconds ksmd should sleep before next scan
+ e.g. "echo 20 > /sys/kernel/mm/ksm/sleep_millisecs"
+ Default: 20 (chosen for demonstration purposes)
+
+run - set 0 to stop ksmd from running but keep merged pages,
+ set 1 to run ksmd e.g. "echo 1 > /sys/kernel/mm/ksm/run",
+ set 2 to stop ksmd and unmerge all pages currently merged,
+ but leave mergeable areas registered for next run
+ Default: 1 (for immediate use by apps which register)
+
+The effectiveness of KSM and MADV_MERGEABLE is shown in /sys/kernel/mm/ksm/:
+
+pages_shared - how many shared unswappable kernel pages KSM is using
+pages_sharing - how many more sites are sharing them i.e. how much saved
+pages_unshared - how many pages unique but repeatedly checked for merging
+pages_volatile - how many pages changing too fast to be placed in a tree
+full_scans - how many times all mergeable areas have been scanned
+
+A high ratio of pages_sharing to pages_shared indicates good sharing, but
+a high ratio of pages_unshared to pages_sharing indicates wasted effort.
+pages_volatile embraces several different kinds of activity, but a high
+proportion there would also indicate poor use of madvise MADV_MERGEABLE.
+
+Izik Eidus,
+Hugh Dickins, 30 July 2009
-----------------------------------------------------------------------------------
--
Unfinished shutdown or reboot
https://bugs.launchpad.net/bugs/418560
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