summaryrefslogtreecommitdiffstats
path: root/Documentation
diff options
context:
space:
mode:
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/auxdisplay/cfag12864b-example.c1
-rw-r--r--Documentation/cgroups/cgroups.txt32
-rw-r--r--Documentation/cgroups/memory.txt41
-rw-r--r--Documentation/crypto/async-tx-api.txt75
-rw-r--r--Documentation/filesystems/sharedsubtree.txt220
-rw-r--r--Documentation/filesystems/vfs.txt7
-rw-r--r--Documentation/ioctl/ioctl-number.txt1
-rw-r--r--Documentation/sysctl/fs.txt17
-rw-r--r--Documentation/sysctl/kernel.txt22
-rw-r--r--Documentation/sysctl/vm.txt41
-rw-r--r--Documentation/vm/.gitignore1
-rw-r--r--Documentation/vm/page-types.c200
12 files changed, 417 insertions, 241 deletions
diff --git a/Documentation/auxdisplay/cfag12864b-example.c b/Documentation/auxdisplay/cfag12864b-example.c
index 1d2c010bae12..e7823ffb1ca0 100644
--- a/Documentation/auxdisplay/cfag12864b-example.c
+++ b/Documentation/auxdisplay/cfag12864b-example.c
@@ -194,7 +194,6 @@ static void cfag12864b_blit(void)
*/
#include <stdio.h>
-#include <string.h>
#define EXAMPLES 6
diff --git a/Documentation/cgroups/cgroups.txt b/Documentation/cgroups/cgroups.txt
index 6eb1a97e88ce..455d4e6d346d 100644
--- a/Documentation/cgroups/cgroups.txt
+++ b/Documentation/cgroups/cgroups.txt
@@ -408,6 +408,26 @@ You can attach the current shell task by echoing 0:
# echo 0 > tasks
+2.3 Mounting hierarchies by name
+--------------------------------
+
+Passing the name=<x> option when mounting a cgroups hierarchy
+associates the given name with the hierarchy. This can be used when
+mounting a pre-existing hierarchy, in order to refer to it by name
+rather than by its set of active subsystems. Each hierarchy is either
+nameless, or has a unique name.
+
+The name should match [\w.-]+
+
+When passing a name=<x> option for a new hierarchy, you need to
+specify subsystems manually; the legacy behaviour of mounting all
+subsystems when none are explicitly specified is not supported when
+you give a subsystem a name.
+
+The name of the subsystem appears as part of the hierarchy description
+in /proc/mounts and /proc/<pid>/cgroups.
+
+
3. Kernel API
=============
@@ -501,7 +521,7 @@ rmdir() will fail with it. From this behavior, pre_destroy() can be
called multiple times against a cgroup.
int can_attach(struct cgroup_subsys *ss, struct cgroup *cgrp,
- struct task_struct *task)
+ struct task_struct *task, bool threadgroup)
(cgroup_mutex held by caller)
Called prior to moving a task into a cgroup; if the subsystem
@@ -509,14 +529,20 @@ returns an error, this will abort the attach operation. If a NULL
task is passed, then a successful result indicates that *any*
unspecified task can be moved into the cgroup. Note that this isn't
called on a fork. If this method returns 0 (success) then this should
-remain valid while the caller holds cgroup_mutex.
+remain valid while the caller holds cgroup_mutex. If threadgroup is
+true, then a successful result indicates that all threads in the given
+thread's threadgroup can be moved together.
void attach(struct cgroup_subsys *ss, struct cgroup *cgrp,
- struct cgroup *old_cgrp, struct task_struct *task)
+ struct cgroup *old_cgrp, struct task_struct *task,
+ bool threadgroup)
(cgroup_mutex held by caller)
Called after the task has been attached to the cgroup, to allow any
post-attachment activity that requires memory allocations or blocking.
+If threadgroup is true, the subsystem should take care of all threads
+in the specified thread's threadgroup. Currently does not support any
+subsystem that might need the old_cgrp for every thread in the group.
void fork(struct cgroup_subsy *ss, struct task_struct *task)
diff --git a/Documentation/cgroups/memory.txt b/Documentation/cgroups/memory.txt
index 23d1262c0775..b871f2552b45 100644
--- a/Documentation/cgroups/memory.txt
+++ b/Documentation/cgroups/memory.txt
@@ -179,6 +179,9 @@ The reclaim algorithm has not been modified for cgroups, except that
pages that are selected for reclaiming come from the per cgroup LRU
list.
+NOTE: Reclaim does not work for the root cgroup, since we cannot set any
+limits on the root cgroup.
+
2. Locking
The memory controller uses the following hierarchy
@@ -210,6 +213,7 @@ We can alter the memory limit:
NOTE: We can use a suffix (k, K, m, M, g or G) to indicate values in kilo,
mega or gigabytes.
NOTE: We can write "-1" to reset the *.limit_in_bytes(unlimited).
+NOTE: We cannot set limits on the root cgroup any more.
# cat /cgroups/0/memory.limit_in_bytes
4194304
@@ -375,7 +379,42 @@ cgroups created below it.
NOTE2: This feature can be enabled/disabled per subtree.
-7. TODO
+7. Soft limits
+
+Soft limits allow for greater sharing of memory. The idea behind soft limits
+is to allow control groups to use as much of the memory as needed, provided
+
+a. There is no memory contention
+b. They do not exceed their hard limit
+
+When the system detects memory contention or low memory control groups
+are pushed back to their soft limits. If the soft limit of each control
+group is very high, they are pushed back as much as possible to make
+sure that one control group does not starve the others of memory.
+
+Please note that soft limits is a best effort feature, it comes with
+no guarantees, but it does its best to make sure that when memory is
+heavily contended for, memory is allocated based on the soft limit
+hints/setup. Currently soft limit based reclaim is setup such that
+it gets invoked from balance_pgdat (kswapd).
+
+7.1 Interface
+
+Soft limits can be setup by using the following commands (in this example we
+assume a soft limit of 256 megabytes)
+
+# echo 256M > memory.soft_limit_in_bytes
+
+If we want to change this to 1G, we can at any time use
+
+# echo 1G > memory.soft_limit_in_bytes
+
+NOTE1: Soft limits take effect over a long period of time, since they involve
+ reclaiming memory for balancing between memory cgroups
+NOTE2: It is recommended to set the soft limit always below the hard limit,
+ otherwise the hard limit will take precedence.
+
+8. TODO
1. Add support for accounting huge pages (as a separate controller)
2. Make per-cgroup scanner reclaim not-shared pages first
diff --git a/Documentation/crypto/async-tx-api.txt b/Documentation/crypto/async-tx-api.txt
index 9f59fcbf5d82..ba046b8fa92f 100644
--- a/Documentation/crypto/async-tx-api.txt
+++ b/Documentation/crypto/async-tx-api.txt
@@ -54,20 +54,23 @@ features surfaced as a result:
3.1 General format of the API:
struct dma_async_tx_descriptor *
-async_<operation>(<op specific parameters>,
- enum async_tx_flags flags,
- struct dma_async_tx_descriptor *dependency,
- dma_async_tx_callback callback_routine,
- void *callback_parameter);
+async_<operation>(<op specific parameters>, struct async_submit ctl *submit)
3.2 Supported operations:
-memcpy - memory copy between a source and a destination buffer
-memset - fill a destination buffer with a byte value
-xor - xor a series of source buffers and write the result to a
- destination buffer
-xor_zero_sum - xor a series of source buffers and set a flag if the
- result is zero. The implementation attempts to prevent
- writes to memory
+memcpy - memory copy between a source and a destination buffer
+memset - fill a destination buffer with a byte value
+xor - xor a series of source buffers and write the result to a
+ destination buffer
+xor_val - xor a series of source buffers and set a flag if the
+ result is zero. The implementation attempts to prevent
+ writes to memory
+pq - generate the p+q (raid6 syndrome) from a series of source buffers
+pq_val - validate that a p and or q buffer are in sync with a given series of
+ sources
+datap - (raid6_datap_recov) recover a raid6 data block and the p block
+ from the given sources
+2data - (raid6_2data_recov) recover 2 raid6 data blocks from the given
+ sources
3.3 Descriptor management:
The return value is non-NULL and points to a 'descriptor' when the operation
@@ -80,8 +83,8 @@ acknowledged by the application before the offload engine driver is allowed to
recycle (or free) the descriptor. A descriptor can be acked by one of the
following methods:
1/ setting the ASYNC_TX_ACK flag if no child operations are to be submitted
-2/ setting the ASYNC_TX_DEP_ACK flag to acknowledge the parent
- descriptor of a new operation.
+2/ submitting an unacknowledged descriptor as a dependency to another
+ async_tx call will implicitly set the acknowledged state.
3/ calling async_tx_ack() on the descriptor.
3.4 When does the operation execute?
@@ -119,30 +122,42 @@ of an operation.
Perform a xor->copy->xor operation where each operation depends on the
result from the previous operation:
-void complete_xor_copy_xor(void *param)
+void callback(void *param)
{
- printk("complete\n");
+ struct completion *cmp = param;
+
+ complete(cmp);
}
-int run_xor_copy_xor(struct page **xor_srcs,
- int xor_src_cnt,
- struct page *xor_dest,
- size_t xor_len,
- struct page *copy_src,
- struct page *copy_dest,
- size_t copy_len)
+void run_xor_copy_xor(struct page **xor_srcs,
+ int xor_src_cnt,
+ struct page *xor_dest,
+ size_t xor_len,
+ struct page *copy_src,
+ struct page *copy_dest,
+ size_t copy_len)
{
struct dma_async_tx_descriptor *tx;
+ addr_conv_t addr_conv[xor_src_cnt];
+ struct async_submit_ctl submit;
+ addr_conv_t addr_conv[NDISKS];
+ struct completion cmp;
+
+ init_async_submit(&submit, ASYNC_TX_XOR_DROP_DST, NULL, NULL, NULL,
+ addr_conv);
+ tx = async_xor(xor_dest, xor_srcs, 0, xor_src_cnt, xor_len, &submit)
- tx = async_xor(xor_dest, xor_srcs, 0, xor_src_cnt, xor_len,
- ASYNC_TX_XOR_DROP_DST, NULL, NULL, NULL);
- tx = async_memcpy(copy_dest, copy_src, 0, 0, copy_len,
- ASYNC_TX_DEP_ACK, tx, NULL, NULL);
- tx = async_xor(xor_dest, xor_srcs, 0, xor_src_cnt, xor_len,
- ASYNC_TX_XOR_DROP_DST | ASYNC_TX_DEP_ACK | ASYNC_TX_ACK,
- tx, complete_xor_copy_xor, NULL);
+ submit->depend_tx = tx;
+ tx = async_memcpy(copy_dest, copy_src, 0, 0, copy_len, &submit);
+
+ init_completion(&cmp);
+ init_async_submit(&submit, ASYNC_TX_XOR_DROP_DST | ASYNC_TX_ACK, tx,
+ callback, &cmp, addr_conv);
+ tx = async_xor(xor_dest, xor_srcs, 0, xor_src_cnt, xor_len, &submit);
async_tx_issue_pending_all();
+
+ wait_for_completion(&cmp);
}
See include/linux/async_tx.h for more information on the flags. See the
diff --git a/Documentation/filesystems/sharedsubtree.txt b/Documentation/filesystems/sharedsubtree.txt
index 736540045dc7..23a181074f94 100644
--- a/Documentation/filesystems/sharedsubtree.txt
+++ b/Documentation/filesystems/sharedsubtree.txt
@@ -4,7 +4,7 @@ Shared Subtrees
Contents:
1) Overview
2) Features
- 3) smount command
+ 3) Setting mount states
4) Use-case
5) Detailed semantics
6) Quiz
@@ -41,14 +41,14 @@ replicas continue to be exactly same.
Here is an example:
- Lets say /mnt has a mount that is shared.
+ Let's say /mnt has a mount that is shared.
mount --make-shared /mnt
- note: mount command does not yet support the --make-shared flag.
- I have included a small C program which does the same by executing
- 'smount /mnt shared'
+ Note: mount(8) command now supports the --make-shared flag,
+ so the sample 'smount' program is no longer needed and has been
+ removed.
- #mount --bind /mnt /tmp
+ # mount --bind /mnt /tmp
The above command replicates the mount at /mnt to the mountpoint /tmp
and the contents of both the mounts remain identical.
@@ -58,8 +58,8 @@ replicas continue to be exactly same.
#ls /tmp
a b c
- Now lets say we mount a device at /tmp/a
- #mount /dev/sd0 /tmp/a
+ Now let's say we mount a device at /tmp/a
+ # mount /dev/sd0 /tmp/a
#ls /tmp/a
t1 t2 t2
@@ -80,21 +80,20 @@ replicas continue to be exactly same.
Here is an example:
- Lets say /mnt has a mount which is shared.
- #mount --make-shared /mnt
+ Let's say /mnt has a mount which is shared.
+ # mount --make-shared /mnt
- Lets bind mount /mnt to /tmp
- #mount --bind /mnt /tmp
+ Let's bind mount /mnt to /tmp
+ # mount --bind /mnt /tmp
the new mount at /tmp becomes a shared mount and it is a replica of
the mount at /mnt.
- Now lets make the mount at /tmp; a slave of /mnt
- #mount --make-slave /tmp
- [or smount /tmp slave]
+ Now let's make the mount at /tmp; a slave of /mnt
+ # mount --make-slave /tmp
- lets mount /dev/sd0 on /mnt/a
- #mount /dev/sd0 /mnt/a
+ let's mount /dev/sd0 on /mnt/a
+ # mount /dev/sd0 /mnt/a
#ls /mnt/a
t1 t2 t3
@@ -104,9 +103,9 @@ replicas continue to be exactly same.
Note the mount event has propagated to the mount at /tmp
- However lets see what happens if we mount something on the mount at /tmp
+ However let's see what happens if we mount something on the mount at /tmp
- #mount /dev/sd1 /tmp/b
+ # mount /dev/sd1 /tmp/b
#ls /tmp/b
s1 s2 s3
@@ -124,12 +123,11 @@ replicas continue to be exactly same.
2d) A unbindable mount is a unbindable private mount
- lets say we have a mount at /mnt and we make is unbindable
+ let's say we have a mount at /mnt and we make is unbindable
- #mount --make-unbindable /mnt
- [ smount /mnt unbindable ]
+ # mount --make-unbindable /mnt
- Lets try to bind mount this mount somewhere else.
+ Let's try to bind mount this mount somewhere else.
# mount --bind /mnt /tmp
mount: wrong fs type, bad option, bad superblock on /mnt,
or too many mounted file systems
@@ -137,149 +135,15 @@ replicas continue to be exactly same.
Binding a unbindable mount is a invalid operation.
-3) smount command
+3) Setting mount states
- Currently the mount command is not aware of shared subtree features.
- Work is in progress to add the support in mount ( util-linux package ).
- Till then use the following program.
+ The mount command (util-linux package) can be used to set mount
+ states:
- ------------------------------------------------------------------------
- //
- //this code was developed my Miklos Szeredi <miklos@szeredi.hu>
- //and modified by Ram Pai <linuxram@us.ibm.com>
- // sample usage:
- // smount /tmp shared
- //
- #include <stdio.h>
- #include <stdlib.h>
- #include <unistd.h>
- #include <string.h>
- #include <sys/mount.h>
- #include <sys/fsuid.h>
-
- #ifndef MS_REC
- #define MS_REC 0x4000 /* 16384: Recursive loopback */
- #endif
-
- #ifndef MS_SHARED
- #define MS_SHARED 1<<20 /* Shared */
- #endif
-
- #ifndef MS_PRIVATE
- #define MS_PRIVATE 1<<18 /* Private */
- #endif
-
- #ifndef MS_SLAVE
- #define MS_SLAVE 1<<19 /* Slave */
- #endif
-
- #ifndef MS_UNBINDABLE
- #define MS_UNBINDABLE 1<<17 /* Unbindable */
- #endif
-
- int main(int argc, char *argv[])
- {
- int type;
- if(argc != 3) {
- fprintf(stderr, "usage: %s dir "
- "<rshared|rslave|rprivate|runbindable|shared|slave"
- "|private|unbindable>\n" , argv[0]);
- return 1;
- }
-
- fprintf(stdout, "%s %s %s\n", argv[0], argv[1], argv[2]);
-
- if (strcmp(argv[2],"rshared")==0)
- type=(MS_SHARED|MS_REC);
- else if (strcmp(argv[2],"rslave")==0)
- type=(MS_SLAVE|MS_REC);
- else if (strcmp(argv[2],"rprivate")==0)
- type=(MS_PRIVATE|MS_REC);
- else if (strcmp(argv[2],"runbindable")==0)
- type=(MS_UNBINDABLE|MS_REC);
- else if (strcmp(argv[2],"shared")==0)
- type=MS_SHARED;
- else if (strcmp(argv[2],"slave")==0)
- type=MS_SLAVE;
- else if (strcmp(argv[2],"private")==0)
- type=MS_PRIVATE;
- else if (strcmp(argv[2],"unbindable")==0)
- type=MS_UNBINDABLE;
- else {
- fprintf(stderr, "invalid operation: %s\n", argv[2]);
- return 1;
- }
- setfsuid(getuid());
-
- if(mount("", argv[1], "dontcare", type, "") == -1) {
- perror("mount");
- return 1;
- }
- return 0;
- }
- -----------------------------------------------------------------------
-
- Copy the above code snippet into smount.c
- gcc -o smount smount.c
-
-
- (i) To mark all the mounts under /mnt as shared execute the following
- command:
-
- smount /mnt rshared
- the corresponding syntax planned for mount command is
- mount --make-rshared /mnt
-
- just to mark a mount /mnt as shared, execute the following
- command:
- smount /mnt shared
- the corresponding syntax planned for mount command is
- mount --make-shared /mnt
-
- (ii) To mark all the shared mounts under /mnt as slave execute the
- following
-
- command:
- smount /mnt rslave
- the corresponding syntax planned for mount command is
- mount --make-rslave /mnt
-
- just to mark a mount /mnt as slave, execute the following
- command:
- smount /mnt slave
- the corresponding syntax planned for mount command is
- mount --make-slave /mnt
-
- (iii) To mark all the mounts under /mnt as private execute the
- following command:
-
- smount /mnt rprivate
- the corresponding syntax planned for mount command is
- mount --make-rprivate /mnt
-
- just to mark a mount /mnt as private, execute the following
- command:
- smount /mnt private
- the corresponding syntax planned for mount command is
- mount --make-private /mnt
-
- NOTE: by default all the mounts are created as private. But if
- you want to change some shared/slave/unbindable mount as
- private at a later point in time, this command can help.
-
- (iv) To mark all the mounts under /mnt as unbindable execute the
- following
-
- command:
- smount /mnt runbindable
- the corresponding syntax planned for mount command is
- mount --make-runbindable /mnt
-
- just to mark a mount /mnt as unbindable, execute the following
- command:
- smount /mnt unbindable
- the corresponding syntax planned for mount command is
- mount --make-unbindable /mnt
+ mount --make-shared mountpoint
+ mount --make-slave mountpoint
+ mount --make-private mountpoint
+ mount --make-unbindable mountpoint
4) Use cases
@@ -350,7 +214,7 @@ replicas continue to be exactly same.
mount --rbind / /view/v3
mount --rbind / /view/v4
- and if /usr has a versioning filesystem mounted, than that
+ and if /usr has a versioning filesystem mounted, then that
mount appears at /view/v1/usr, /view/v2/usr, /view/v3/usr and
/view/v4/usr too
@@ -390,7 +254,7 @@ replicas continue to be exactly same.
For example:
mount --make-shared /mnt
- mount --bin /mnt /tmp
+ mount --bind /mnt /tmp
The mount at /mnt and that at /tmp are both shared and belong
to the same peer group. Anything mounted or unmounted under
@@ -558,7 +422,7 @@ replicas continue to be exactly same.
then the subtree under the unbindable mount is pruned in the new
location.
- eg: lets say we have the following mount tree.
+ eg: let's say we have the following mount tree.
A
/ \
@@ -566,7 +430,7 @@ replicas continue to be exactly same.
/ \ / \
D E F G
- Lets say all the mount except the mount C in the tree are
+ Let's say all the mount except the mount C in the tree are
of a type other than unbindable.
If this tree is rbound to say Z
@@ -683,13 +547,13 @@ replicas continue to be exactly same.
'b' on mounts that receive propagation from mount 'B' and does not have
sub-mounts within them are unmounted.
- Example: Lets say 'B1', 'B2', 'B3' are shared mounts that propagate to
+ Example: Let's say 'B1', 'B2', 'B3' are shared mounts that propagate to
each other.
- lets say 'A1', 'A2', 'A3' are first mounted at dentry 'b' on mount
+ let's say 'A1', 'A2', 'A3' are first mounted at dentry 'b' on mount
'B1', 'B2' and 'B3' respectively.
- lets say 'C1', 'C2', 'C3' are next mounted at the same dentry 'b' on
+ let's say 'C1', 'C2', 'C3' are next mounted at the same dentry 'b' on
mount 'B1', 'B2' and 'B3' respectively.
if 'C1' is unmounted, all the mounts that are most-recently-mounted on
@@ -710,7 +574,7 @@ replicas continue to be exactly same.
A cloned namespace contains all the mounts as that of the parent
namespace.
- Lets say 'A' and 'B' are the corresponding mounts in the parent and the
+ Let's say 'A' and 'B' are the corresponding mounts in the parent and the
child namespace.
If 'A' is shared, then 'B' is also shared and 'A' and 'B' propagate to
@@ -759,11 +623,11 @@ replicas continue to be exactly same.
mount --make-slave /mnt
At this point we have the first mount at /tmp and
- its root dentry is 1. Lets call this mount 'A'
+ its root dentry is 1. Let's call this mount 'A'
And then we have a second mount at /tmp1 with root
- dentry 2. Lets call this mount 'B'
+ dentry 2. Let's call this mount 'B'
Next we have a third mount at /mnt with root dentry
- mnt. Lets call this mount 'C'
+ mnt. Let's call this mount 'C'
'B' is the slave of 'A' and 'C' is a slave of 'B'
A -> B -> C
@@ -794,7 +658,7 @@ replicas continue to be exactly same.
Q3 Why is unbindable mount needed?
- Lets say we want to replicate the mount tree at multiple
+ Let's say we want to replicate the mount tree at multiple
locations within the same subtree.
if one rbind mounts a tree within the same subtree 'n' times
@@ -803,7 +667,7 @@ replicas continue to be exactly same.
mounts. Here is a example.
step 1:
- lets say the root tree has just two directories with
+ let's say the root tree has just two directories with
one vfsmount.
root
/ \
@@ -875,7 +739,7 @@ replicas continue to be exactly same.
Unclonable mounts come in handy here.
step 1:
- lets say the root tree has just two directories with
+ let's say the root tree has just two directories with
one vfsmount.
root
/ \
diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt
index f49eecf2e573..623f094c9d8d 100644
--- a/Documentation/filesystems/vfs.txt
+++ b/Documentation/filesystems/vfs.txt
@@ -536,6 +536,7 @@ struct address_space_operations {
/* migrate the contents of a page to the specified target */
int (*migratepage) (struct page *, struct page *);
int (*launder_page) (struct page *);
+ int (*error_remove_page) (struct mapping *mapping, struct page *page);
};
writepage: called by the VM to write a dirty page to backing store.
@@ -694,6 +695,12 @@ struct address_space_operations {
prevent redirtying the page, it is kept locked during the whole
operation.
+ error_remove_page: normally set to generic_error_remove_page if truncation
+ is ok for this address space. Used for memory failure handling.
+ Setting this implies you deal with pages going away under you,
+ unless you have them locked or reference counts increased.
+
+
The File Object
===============
diff --git a/Documentation/ioctl/ioctl-number.txt b/Documentation/ioctl/ioctl-number.txt
index aafca0a8f66a..947374977ca5 100644
--- a/Documentation/ioctl/ioctl-number.txt
+++ b/Documentation/ioctl/ioctl-number.txt
@@ -135,6 +135,7 @@ Code Seq# Include File Comments
<http://mikonos.dia.unisa.it/tcfs>
'l' 40-7F linux/udf_fs_i.h in development:
<http://sourceforge.net/projects/linux-udf/>
+'m' 00-09 linux/mmtimer.h
'm' all linux/mtio.h conflict!
'm' all linux/soundcard.h conflict!
'm' all linux/synclink.h conflict!
diff --git a/Documentation/sysctl/fs.txt b/Documentation/sysctl/fs.txt
index 1458448436cc..62682500878a 100644
--- a/Documentation/sysctl/fs.txt
+++ b/Documentation/sysctl/fs.txt
@@ -96,13 +96,16 @@ handles that the Linux kernel will allocate. When you get lots
of error messages about running out of file handles, you might
want to increase this limit.
-The three values in file-nr denote the number of allocated
-file handles, the number of unused file handles and the maximum
-number of file handles. When the allocated file handles come
-close to the maximum, but the number of unused file handles is
-significantly greater than 0, you've encountered a peak in your
-usage of file handles and you don't need to increase the maximum.
-
+Historically, the three values in file-nr denoted the number of
+allocated file handles, the number of allocated but unused file
+handles, and the maximum number of file handles. Linux 2.6 always
+reports 0 as the number of free file handles -- this is not an
+error, it just means that the number of allocated file handles
+exactly matches the number of used file handles.
+
+Attempts to allocate more file descriptors than file-max are
+reported with printk, look for "VFS: file-max limit <number>
+reached".
==============================================================
nr_open:
diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt
index b3d8b4922740..a028b92001ed 100644
--- a/Documentation/sysctl/kernel.txt
+++ b/Documentation/sysctl/kernel.txt
@@ -22,6 +22,7 @@ show up in /proc/sys/kernel:
- callhome [ S390 only ]
- auto_msgmni
- core_pattern
+- core_pipe_limit
- core_uses_pid
- ctrl-alt-del
- dentry-state
@@ -135,6 +136,27 @@ core_pattern is used to specify a core dumpfile pattern name.
==============================================================
+core_pipe_limit:
+
+This sysctl is only applicable when core_pattern is configured to pipe core
+files to user space helper a (when the first character of core_pattern is a '|',
+see above). When collecting cores via a pipe to an application, it is
+occasionally usefull for the collecting application to gather data about the
+crashing process from its /proc/pid directory. In order to do this safely, the
+kernel must wait for the collecting process to exit, so as not to remove the
+crashing processes proc files prematurely. This in turn creates the possibility
+that a misbehaving userspace collecting process can block the reaping of a
+crashed process simply by never exiting. This sysctl defends against that. It
+defines how many concurrent crashing processes may be piped to user space
+applications in parallel. If this value is exceeded, then those crashing
+processes above that value are noted via the kernel log and their cores are
+skipped. 0 is a special value, indicating that unlimited processes may be
+captured in parallel, but that no waiting will take place (i.e. the collecting
+process is not guaranteed access to /proc/<crahing pid>/). This value defaults
+to 0.
+
+==============================================================
+
core_uses_pid:
The default coredump filename is "core". By setting
diff --git a/Documentation/sysctl/vm.txt b/Documentation/sysctl/vm.txt
index e6fb1ec2744b..a6e360d2055c 100644
--- a/Documentation/sysctl/vm.txt
+++ b/Documentation/sysctl/vm.txt
@@ -32,6 +32,8 @@ Currently, these files are in /proc/sys/vm:
- legacy_va_layout
- lowmem_reserve_ratio
- max_map_count
+- memory_failure_early_kill
+- memory_failure_recovery
- min_free_kbytes
- min_slab_ratio
- min_unmapped_ratio
@@ -53,7 +55,6 @@ Currently, these files are in /proc/sys/vm:
- vfs_cache_pressure
- zone_reclaim_mode
-
==============================================================
block_dump
@@ -275,6 +276,44 @@ e.g., up to one or two maps per allocation.
The default value is 65536.
+=============================================================
+
+memory_failure_early_kill:
+
+Control how to kill processes when uncorrected memory error (typically
+a 2bit error in a memory module) is detected in the background by hardware
+that cannot be handled by the kernel. In some cases (like the page
+still having a valid copy on disk) the kernel will handle the failure
+transparently without affecting any applications. But if there is
+no other uptodate copy of the data it will kill to prevent any data
+corruptions from propagating.
+
+1: Kill all processes that have the corrupted and not reloadable page mapped
+as soon as the corruption is detected. Note this is not supported
+for a few types of pages, like kernel internally allocated data or
+the swap cache, but works for the majority of user pages.
+
+0: Only unmap the corrupted page from all processes and only kill a process
+who tries to access it.
+
+The kill is done using a catchable SIGBUS with BUS_MCEERR_AO, so processes can
+handle this if they want to.
+
+This is only active on architectures/platforms with advanced machine
+check handling and depends on the hardware capabilities.
+
+Applications can override this setting individually with the PR_MCE_KILL prctl
+
+==============================================================
+
+memory_failure_recovery
+
+Enable memory failure recovery (when supported by the platform)
+
+1: Attempt recovery.
+
+0: Always panic on a memory failure.
+
==============================================================
min_free_kbytes:
diff --git a/Documentation/vm/.gitignore b/Documentation/vm/.gitignore
index 33e8a023df02..09b164a5700f 100644
--- a/Documentation/vm/.gitignore
+++ b/Documentation/vm/.gitignore
@@ -1 +1,2 @@
+page-types
slabinfo
diff --git a/Documentation/vm/page-types.c b/Documentation/vm/page-types.c
index 3eda8ea00852..fa1a30d9e9d5 100644
--- a/Documentation/vm/page-types.c
+++ b/Documentation/vm/page-types.c
@@ -5,6 +5,7 @@
* Copyright (C) 2009 Wu Fengguang <fengguang.wu@intel.com>
*/
+#define _LARGEFILE64_SOURCE
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
@@ -13,12 +14,33 @@
#include <string.h>
#include <getopt.h>
#include <limits.h>
+#include <assert.h>
#include <sys/types.h>
#include <sys/errno.h>
#include <sys/fcntl.h>
/*
+ * pagemap kernel ABI bits
+ */
+
+#define PM_ENTRY_BYTES sizeof(uint64_t)
+#define PM_STATUS_BITS 3
+#define PM_STATUS_OFFSET (64 - PM_STATUS_BITS)
+#define PM_STATUS_MASK (((1LL << PM_STATUS_BITS) - 1) << PM_STATUS_OFFSET)
+#define PM_STATUS(nr) (((nr) << PM_STATUS_OFFSET) & PM_STATUS_MASK)
+#define PM_PSHIFT_BITS 6
+#define PM_PSHIFT_OFFSET (PM_STATUS_OFFSET - PM_PSHIFT_BITS)
+#define PM_PSHIFT_MASK (((1LL << PM_PSHIFT_BITS) - 1) << PM_PSHIFT_OFFSET)
+#define PM_PSHIFT(x) (((u64) (x) << PM_PSHIFT_OFFSET) & PM_PSHIFT_MASK)
+#define PM_PFRAME_MASK ((1LL << PM_PSHIFT_OFFSET) - 1)
+#define PM_PFRAME(x) ((x) & PM_PFRAME_MASK)
+
+#define PM_PRESENT PM_STATUS(4LL)
+#define PM_SWAP PM_STATUS(2LL)
+
+
+/*
* kernel page flags
*/
@@ -126,6 +148,14 @@ static int nr_addr_ranges;
static unsigned long opt_offset[MAX_ADDR_RANGES];
static unsigned long opt_size[MAX_ADDR_RANGES];
+#define MAX_VMAS 10240
+static int nr_vmas;
+static unsigned long pg_start[MAX_VMAS];
+static unsigned long pg_end[MAX_VMAS];
+static unsigned long voffset;
+
+static int pagemap_fd;
+
#define MAX_BIT_FILTERS 64
static int nr_bit_filters;
static uint64_t opt_mask[MAX_BIT_FILTERS];
@@ -135,7 +165,6 @@ static int page_size;
#define PAGES_BATCH (64 << 10) /* 64k pages */
static int kpageflags_fd;
-static uint64_t kpageflags_buf[KPF_BYTES * PAGES_BATCH];
#define HASH_SHIFT 13
#define HASH_SIZE (1 << HASH_SHIFT)
@@ -158,6 +187,11 @@ static uint64_t page_flags[HASH_SIZE];
type __min2 = (y); \
__min1 < __min2 ? __min1 : __min2; })
+#define max_t(type, x, y) ({ \
+ type __max1 = (x); \
+ type __max2 = (y); \
+ __max1 > __max2 ? __max1 : __max2; })
+
static unsigned long pages2mb(unsigned long pages)
{
return (pages * page_size) >> 20;
@@ -224,26 +258,34 @@ static char *page_flag_longname(uint64_t flags)
static void show_page_range(unsigned long offset, uint64_t flags)
{
static uint64_t flags0;
+ static unsigned long voff;
static unsigned long index;
static unsigned long count;
- if (flags == flags0 && offset == index + count) {
+ if (flags == flags0 && offset == index + count &&
+ (!opt_pid || voffset == voff + count)) {
count++;
return;
}
- if (count)
- printf("%lu\t%lu\t%s\n",
+ if (count) {
+ if (opt_pid)
+ printf("%lx\t", voff);
+ printf("%lx\t%lx\t%s\n",
index, count, page_flag_name(flags0));
+ }
flags0 = flags;
index = offset;
+ voff = voffset;
count = 1;
}
static void show_page(unsigned long offset, uint64_t flags)
{
- printf("%lu\t%s\n", offset, page_flag_name(flags));
+ if (opt_pid)
+ printf("%lx\t", voffset);
+ printf("%lx\t%s\n", offset, page_flag_name(flags));
}
static void show_summary(void)
@@ -383,6 +425,8 @@ static void walk_pfn(unsigned long index, unsigned long count)
lseek(kpageflags_fd, index * KPF_BYTES, SEEK_SET);
while (count) {
+ uint64_t kpageflags_buf[KPF_BYTES * PAGES_BATCH];
+
batch = min_t(unsigned long, count, PAGES_BATCH);
n = read(kpageflags_fd, kpageflags_buf, batch * KPF_BYTES);
if (n == 0)
@@ -404,6 +448,81 @@ static void walk_pfn(unsigned long index, unsigned long count)
}
}
+
+#define PAGEMAP_BATCH 4096
+static unsigned long task_pfn(unsigned long pgoff)
+{
+ static uint64_t buf[PAGEMAP_BATCH];
+ static unsigned long start;
+ static long count;
+ uint64_t pfn;
+
+ if (pgoff < start || pgoff >= start + count) {
+ if (lseek64(pagemap_fd,
+ (uint64_t)pgoff * PM_ENTRY_BYTES,
+ SEEK_SET) < 0) {
+ perror("pagemap seek");
+ exit(EXIT_FAILURE);
+ }
+ count = read(pagemap_fd, buf, sizeof(buf));
+ if (count == 0)
+ return 0;
+ if (count < 0) {
+ perror("pagemap read");
+ exit(EXIT_FAILURE);
+ }
+ if (count % PM_ENTRY_BYTES) {
+ fatal("pagemap read not aligned.\n");
+ exit(EXIT_FAILURE);
+ }
+ count /= PM_ENTRY_BYTES;
+ start = pgoff;
+ }
+
+ pfn = buf[pgoff - start];
+ if (pfn & PM_PRESENT)
+ pfn = PM_PFRAME(pfn);
+ else
+ pfn = 0;
+
+ return pfn;
+}
+
+static void walk_task(unsigned long index, unsigned long count)
+{
+ int i = 0;
+ const unsigned long end = index + count;
+
+ while (index < end) {
+
+ while (pg_end[i] <= index)
+ if (++i >= nr_vmas)
+ return;
+ if (pg_start[i] >= end)
+ return;
+
+ voffset = max_t(unsigned long, pg_start[i], index);
+ index = min_t(unsigned long, pg_end[i], end);
+
+ assert(voffset < index);
+ for (; voffset < index; voffset++) {
+ unsigned long pfn = task_pfn(voffset);
+ if (pfn)
+ walk_pfn(pfn, 1);
+ }
+ }
+}
+
+static void add_addr_range(unsigned long offset, unsigned long size)
+{
+ if (nr_addr_ranges >= MAX_ADDR_RANGES)
+ fatal("too many addr ranges\n");
+
+ opt_offset[nr_addr_ranges] = offset;
+ opt_size[nr_addr_ranges] = min_t(unsigned long, size, ULONG_MAX-offset);
+ nr_addr_ranges++;
+}
+
static void walk_addr_ranges(void)
{
int i;
@@ -415,10 +534,13 @@ static void walk_addr_ranges(void)
}
if (!nr_addr_ranges)
- walk_pfn(0, ULONG_MAX);
+ add_addr_range(0, ULONG_MAX);
for (i = 0; i < nr_addr_ranges; i++)
- walk_pfn(opt_offset[i], opt_size[i]);
+ if (!opt_pid)
+ walk_pfn(opt_offset[i], opt_size[i]);
+ else
+ walk_task(opt_offset[i], opt_size[i]);
close(kpageflags_fd);
}
@@ -446,8 +568,8 @@ static void usage(void)
" -r|--raw Raw mode, for kernel developers\n"
" -a|--addr addr-spec Walk a range of pages\n"
" -b|--bits bits-spec Walk pages with specified bits\n"
-#if 0 /* planned features */
" -p|--pid pid Walk process address space\n"
+#if 0 /* planned features */
" -f|--file filename Walk file address space\n"
#endif
" -l|--list Show page details in ranges\n"
@@ -459,7 +581,7 @@ static void usage(void)
" N+M pages range from N to N+M-1\n"
" N,M pages range from N to M-1\n"
" N, pages range from N to end\n"
-" ,M pages range from 0 to M\n"
+" ,M pages range from 0 to M-1\n"
"bits-spec:\n"
" bit1,bit2 (flags & (bit1|bit2)) != 0\n"
" bit1,bit2=bit1 (flags & (bit1|bit2)) == bit1\n"
@@ -496,21 +618,57 @@ static unsigned long long parse_number(const char *str)
static void parse_pid(const char *str)
{
+ FILE *file;
+ char buf[5000];
+
opt_pid = parse_number(str);
-}
-static void parse_file(const char *name)
-{
+ sprintf(buf, "/proc/%d/pagemap", opt_pid);
+ pagemap_fd = open(buf, O_RDONLY);
+ if (pagemap_fd < 0) {
+ perror(buf);
+ exit(EXIT_FAILURE);
+ }
+
+ sprintf(buf, "/proc/%d/maps", opt_pid);
+ file = fopen(buf, "r");
+ if (!file) {
+ perror(buf);
+ exit(EXIT_FAILURE);
+ }
+
+ while (fgets(buf, sizeof(buf), file) != NULL) {
+ unsigned long vm_start;
+ unsigned long vm_end;
+ unsigned long long pgoff;
+ int major, minor;
+ char r, w, x, s;
+ unsigned long ino;
+ int n;
+
+ n = sscanf(buf, "%lx-%lx %c%c%c%c %llx %x:%x %lu",
+ &vm_start,
+ &vm_end,
+ &r, &w, &x, &s,
+ &pgoff,
+ &major, &minor,
+ &ino);
+ if (n < 10) {
+ fprintf(stderr, "unexpected line: %s\n", buf);
+ continue;
+ }
+ pg_start[nr_vmas] = vm_start / page_size;
+ pg_end[nr_vmas] = vm_end / page_size;
+ if (++nr_vmas >= MAX_VMAS) {
+ fprintf(stderr, "too many VMAs\n");
+ break;
+ }
+ }
+ fclose(file);
}
-static void add_addr_range(unsigned long offset, unsigned long size)
+static void parse_file(const char *name)
{
- if (nr_addr_ranges >= MAX_ADDR_RANGES)
- fatal("too much addr ranges\n");
-
- opt_offset[nr_addr_ranges] = offset;
- opt_size[nr_addr_ranges] = size;
- nr_addr_ranges++;
}
static void parse_addr_range(const char *optarg)
@@ -676,8 +834,10 @@ int main(int argc, char *argv[])
}
}
+ if (opt_list && opt_pid)
+ printf("voffset\t");
if (opt_list == 1)
- printf("offset\tcount\tflags\n");
+ printf("offset\tlen\tflags\n");
if (opt_list == 2)
printf("offset\tflags\n");
generated by cgit v1.2.3 (git 2.39.1) at 2024-08-03 12:23:50 +0000