Use the search_dirblock() in ext4_dx_find_entry(). It makes the code
easier to read, and it takes advantage of common code. It also saves
100 bytes or so of text space.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: Brad Spengler <spender@grsecurity.net>
If the first block of htree directory is missing '.' or '..' but is
otherwise a valid directory, and we do a lookup for '.' or '..', it's
possible to dereference an uninitialized memory pointer in
ext4_htree_next_block().
We avoid this by moving the special case from ext4_dx_find_entry() to
ext4_find_entry(); this also means we can optimize ext4_find_entry()
slightly when NFS looks up "..".
Thanks to Brad Spengler for pointing a Clang warning that led me to
look more closely at this code. The warning was harmless, but it was
useful in pointing out code that was too ugly to live. This warning was
also reported by Roman Borisov.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: Brad Spengler <spender@grsecurity.net>
Not that these take up a lot of room, but the structure is long enough
as it is, and there's no need to confuse people with these various
undocumented & unused structure members...
Signed-off-by: Eric Sandeen <sandeen@redaht.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
By queuing the io end on the unwritten workqueue before adding it
to our inode's list of completed IOs, I think we run the risk
of the work getting completed, and the IO freed, before we try
to add it to the inode's i_completed_io_list.
It should be safe to add it to the inode's list of completed
IOs, and -then- queue it for completion, I think.
Thanks to Dave Chinner for pointing out the race.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Jiaying Zhang <jiayingz@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Many tracepoints were populating an ext4_allocation_context
to pass in, but this requires a slab allocation even when
tracepoints are off. In fact, 4 of 5 of these allocations
were only for tracing. In addition, we were only using a
small fraction of the 144 bytes of this structure for this
purpose.
We can do away with all these alloc/frees of the ac and
simply pass in the bits we care about, instead.
I tested this by turning on tracing and running through
xfstests on x86_64. I did not actually do anything with
the trace output, however.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Our QA reported an oops in the ext4_mb_release_group_pa tracing,
and Josef Bacik pointed out that it was because we may have a
non-null but uninitialized ac_inode in the allocation context.
I can reproduce it when running xfstests with ext4 tracepoints on,
on a CONFIG_SLAB_DEBUG kernel.
We call trace_ext4_mb_release_group_pa from 2 places,
ext4_mb_discard_group_preallocations and
ext4_mb_discard_lg_preallocations
In both cases we allocate an ac as a container just for tracing (!)
and never fill in the ac_inode. There's no reason to be assigning,
testing, or printing it as far as I can see, so just remove it from
the tracepoint.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Josef Bacik <josef@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
On linux-2.6.36-rc2, if we execute the following script, we can hang
the system when the /bin/sync command is executed:
========================================================================
#!/bin/sh
echo -n "HANG UP TEST: "
/bin/dd if=/dev/zero of=/tmp/img bs=1k count=1 seek=1M 2> /dev/null
/sbin/mkfs.ext4 -Fq /tmp/img
/bin/mount -o loop -t ext4 /tmp/img /mnt
/bin/dd if=/dev/zero of=/mnt/file bs=1 count=1 \
seek=$((16*1024*1024*1024*1024-4096)) 2> /dev/null
/bin/sync
/bin/umount /mnt
echo "DONE"
exit 0
========================================================================
We can see the following backtrace if we get the kdump when this
hangup occurs:
======================================================================
kthread()
=> bdi_writeback_thread()
=> wb_do_writeback()
=> wb_writeback()
=> writeback_inodes_wb()
=> writeback_sb_inodes()
=> writeback_single_inode()
=> ext4_da_writepages() ---+
^ infinite |
| loop |
+-------------+
======================================================================
The reason why this hangup happens is described as follows:
1) We write the last extent block of the file whose size is the filesystem
maximum size.
2) "BH_Delay" flag is set on the buffer_head of its block.
3) - the member, "m_lblk" of struct mpage_da_data is 4294967295 (UINT_MAX)
- the member, "m_len" of struct mpage_da_data is 1
mpage_put_bnr_to_bhs() which is called via ext4_da_writepages()
cannot clear "BH_Delay" flag of the buffer_head because the type of
m_lblk is ext4_lblk_t and then m_lblk + m_len is overflow.
Therefore an infinite loop occurs because ext4_da_writepages()
cannot write the page (which corresponds to the block) since
"BH_Delay" flag isn't cleared.
----------------------------------------------------------------------
static void mpage_put_bnr_to_bhs(struct mpage_da_data *mpd,
struct ext4_map_blocks *map)
{
...
int blocks = map->m_len;
...
do {
// cur_logical = 4294967295
// map->m_lblk = 4294967295
// blocks = 1
// *** map->m_lblk + blocks == 0 (OVERFLOW!) ***
// (cur_logical >= map->m_lblk + blocks) => true
if (cur_logical >= map->m_lblk + blocks)
break;
----------------------------------------------------------------------
NOTE: Mounting with the nodelalloc option will avoid this codepath,
and thus, avoid this hang
Signed-off-by: Toshiyuki Okajima <toshi.okajima@jp.fujitsu.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
The llseek system call should return EINVAL if passed a seek offset
which results in a write error. What this maximum offset should be
depends on whether or not the huge_file file system feature is set,
and whether or not the file is extent based or not.
If the file has no "EXT4_EXTENTS_FL" flag, the maximum size which can be
written (write systemcall) is different from the maximum size which can be
sought (lseek systemcall).
For example, the following 2 cases demonstrates the differences
between the maximum size which can be written, versus the seek offset
allowed by the llseek system call:
#1: mkfs.ext3 <dev>; mount -t ext4 <dev>
#2: mkfs.ext3 <dev>; tune2fs -Oextent,huge_file <dev>; mount -t ext4 <dev>
Table. the max file size which we can write or seek
at each filesystem feature tuning and file flag setting
+============+===============================+===============================+
| \ File flag| | |
| \ | !EXT4_EXTENTS_FL | EXT4_EXTETNS_FL |
|case \| | |
+------------+-------------------------------+-------------------------------+
| #1 | write: 2194719883264 | write: -------------- |
| | seek: 2199023251456 | seek: -------------- |
+------------+-------------------------------+-------------------------------+
| #2 | write: 4402345721856 | write: 17592186044415 |
| | seek: 17592186044415 | seek: 17592186044415 |
+------------+-------------------------------+-------------------------------+
The differences exist because ext4 has 2 maxbytes which are sb->s_maxbytes
(= extent-mapped maxbytes) and EXT4_SB(sb)->s_bitmap_maxbytes (= block-mapped
maxbytes). Although generic_file_llseek uses only extent-mapped maxbytes.
(llseek of ext4_file_operations is generic_file_llseek which uses
sb->s_maxbytes.)
Therefore we create ext4 llseek function which uses 2 maxbytes.
The new own function originates from generic_file_llseek().
If the file flag, "EXT4_EXTENTS_FL" is not set, the function alters
inode->i_sb->s_maxbytes into EXT4_SB(inode->i_sb)->s_bitmap_maxbytes.
Signed-off-by: Toshiyuki Okajima <toshi.okajima@jp.fujitsu.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
An ext4 filesystem on a read-only device, with an external journal
which is at a different device number then recorded in the superblock
will fail to honor the read-only setting of the device and trigger
a superblock update (write).
For example:
- ext4 on a software raid which is in read-only mode
- external journal on a read-write device which has changed device num
- attempt to mount with -o journal_dev=<new_number>
- hits BUG_ON(mddev->ro = 1) in md.c
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Maciej Żenczykowski <zenczykowski@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Change ext4_ext_zeroout to use sb_issue_zeroout instead of its
own approach to zero out extents.
Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Use sb_issue_zeroout to zero out inode table and descriptor table
blocks instead of old approach which involves journaling.
Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
User-space should have the opportunity to check what features doest ext4
support in each particular copy. This adds easy interface by creating new
"features" directory in sys/fs/ext4/. In that directory files
advertising feature names can be created.
Add lazy_itable_init to the feature list.
Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
When the lazy_itable_init extended option is passed to mke2fs, it
considerably speeds up filesystem creation because inode tables are
not zeroed out. The fact that parts of the inode table are
uninitialized is not a problem so long as the block group descriptors,
which contain information regarding how much of the inode table has
been initialized, has not been corrupted However, if the block group
checksums are not valid, e2fsck must scan the entire inode table, and
the the old, uninitialized data could potentially cause e2fsck to
report false problems.
Hence, it is important for the inode tables to be initialized as soon
as possble. This commit adds this feature so that mke2fs can safely
use the lazy inode table initialization feature to speed up formatting
file systems.
This is done via a new new kernel thread called ext4lazyinit, which is
created on demand and destroyed, when it is no longer needed. There
is only one thread for all ext4 filesystems in the system. When the
first filesystem with inititable mount option is mounted, ext4lazyinit
thread is created, then the filesystem can register its request in the
request list.
This thread then walks through the list of requests picking up
scheduled requests and invoking ext4_init_inode_table(). Next schedule
time for the request is computed by multiplying the time it took to
zero out last inode table with wait multiplier, which can be set with
the (init_itable=n) mount option (default is 10). We are doing
this so we do not take the whole I/O bandwidth. When the thread is no
longer necessary (request list is empty) it frees the appropriate
structures and exits (and can be created later later by another
filesystem).
We do not disturb regular inode allocations in any way, it just do not
care whether the inode table is, or is not zeroed. But when zeroing, we
have to skip used inodes, obviously. Also we should prevent new inode
allocations from the group, while zeroing is on the way. For that we
take write alloc_sem lock in ext4_init_inode_table() and read alloc_sem
in the ext4_claim_inode, so when we are unlucky and allocator hits the
group which is currently being zeroed, it just has to wait.
This can be suppresed using the mount option no_init_itable.
Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This is done the same way as helper sb_issue_discard for
blkdev_issue_discard.
Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
An attempt to modify the file system during the call to
jbd2_destroy_journal() can lead to a system lockup. So add some
checking to make it much more obvious when this happens to and to
determine where the offending code is located.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
We can't hold the block group spinlock because we ext4_issue_discard()
calls wait and hence can get rescheduled.
Google-Bug-Id: 3017678
Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
I'm uneasy with lots of stuff going on in ext4_da_writepages(),
but bumping nr_to_write from LLONG_MAX to -8 clearly isn't
making anything better, so avoid the multiplier in that case.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Today we simply break out of the inner loop when we have accumulated
max_pages; this keeps scanning forwad and doing pagevec_lookup_tag()
in the while (!done) loop, this does potentially a lot of work
with no net effect.
When we have accumulated max_pages, just clean up and return.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
ext4_group_info structures are currently allocated with kmalloc().
With a typical 4K block size, these are 136 bytes each -- meaning
they'll each consume a 256-byte slab object. On a system with many
ext4 large partitions, that's a lot of wasted kernel slab space.
(E.g., a single 1TB partition will have about 8000 block groups, using
about 2MB of slab, of which nearly 1MB is wasted.)
This patch creates an array of slab pointers created as needed --
depending on the superblock block size -- and uses these slabs to
allocate the group info objects.
Google-Bug-Id: 2980809
Signed-off-by: Curt Wohlgemuth <curtw@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Evergreen now has blit support, but unmappable vram support
was disabled in c919b371cb
(drm/radeon/kms: avoid corner case issue with unmappable vram V2)
due to merge ordering. This re-enables unmappable vram on
evergreen.
Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Calculate height based on the slice bitfield rather than the size.
Same as Dave's CB fix.
Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
There are cases when multiple texture units have to be enabled,
but not actually used to sample. This patch checks to see if
the lookup_disable bit is set and if so, skips the texture check.
Fixes:
https://bugs.freedesktop.org/show_bug.cgi?id=25544
Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Cc: stable@kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>
This fixes a hang seen in jbd2_journal_release_jbd_inode
on a lot of Power 6 systems running with ext4. When we get
in the hung state, all I/O to the disk in question gets blocked
where we stay indefinitely. Looking at the task list, I can see
we are stuck in jbd2_journal_release_jbd_inode waiting on a
wake up. I added some debug code to detect this scenario and
dump additional data if we were stuck in jbd2_journal_release_jbd_inode
for longer than 30 minutes. When it hit, I was able to see that
i_flags was 0, suggesting we missed the wake up.
This patch changes i_flags to be an unsigned long, uses bit operators
to access it, and adds barriers around the accesses. Prior to applying
this patch, we were regularly hitting this hang on numerous systems
in our test environment. After applying the patch, the hangs no longer
occur.
Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
It turns out we have several problems with how EOFBLOCKS_FL is
handled. First of all, there was a fencepost error where we were not
clearing the EOFBLOCKS_FL when fill in the last uninitialized block,
but rather when we allocate the next block _after_ the uninitalized
block. Secondly we were not testing to see if we needed to clear the
EOFBLOCKS_FL when writing to the file O_DIRECT or when were converting
an uninitialized block (which is the most common case).
Google-Bug-Id: 2928259
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
In commit f7347ce4ee ("fasync: re-organize fasync entry insertion to
allow it under a spinlock") Arnd took an earlier patch of mine that had
the comment about the FASYNC flag above the wrong function.
When the fasync_add_entry() function was split to introduce the new
fasync_insert_entry() helper function, the code that actually cares
about the FASYNC bit moved to that new helper.
So just move the comment to the right point.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'flock' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl:
locks: turn lock_flocks into a spinlock
fasync: re-organize fasync entry insertion to allow it under a spinlock
locks/nfsd: allocate file lock outside of spinlock
lockd: fix nlmsvc_notify_blocked locking
lockd: push lock_flocks down
This make epoll use hrtimers for the timeout value which prevents
epoll_wait() from timing out up to a millisecond early.
This mirrors the behavior of select() and poll().
Signed-off-by: Shawn Bohrer <shawn.bohrer@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Davide Libenzi <davidel@xmailserver.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Make it a subsystem-specific identifier because we wish to amke it
non-static in the next patch ("epoll: make epoll_wait() use the hrtimer
range feature").
Cc: Shawn Bohrer <shawn.bohrer@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Davide Libenzi <davidel@xmailserver.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
As each board and system has different memory for ramoops. It's better to
define the platform data instead of module params.
[akpm@linux-foundation.org: fix ramoops_remove() return type]
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Marco Stornelli <marco.stornelli@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If the same resource is inserted to the resource tree (maybe not on
purpose), a dead loop will be created. In this situation, The kernel does
not report any warning or error :(
The command below will show a endless print.
#cat /proc/iomem
[akpm@linux-foundation.org: add WARN_ON()]
Signed-off-by: Huang Shijie <shijie8@gmail.com>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add a new __kfifo_int_must_check_helper() helper function, which is needed
for kfifo_alloc() to return the right signed integer value.
The origin __kfifo_must_check_helper() helper was renamed into
__kfifo_uint_must_check_helper() to show the sign which is expected and
returned.
(And revert the temporary disabling of __kfifo_must_check_helper())
Signed-off-by: Stefani Seibold <stefani@seibold.net>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The search/pullup/add/remove device attributes were 0666 which would allow
arbitrary users to affect the 1 wire bus. Change to 0664 to prevent that.
I found this patch in the Android tree, apparently this has never been
sent upstream so doing it now.
Signed-off-by: Brian Swetland <swetland@google.com>
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
dma_addr_t is always 64 bit on alpha. So let's use dma_addr_t instead.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
dma64_addr_t looks pointless (at least there is no point that an
architecture has the own dma64_addr_t typedef).
dma_addr_t is set to 32 or 64 bits appropriately. You can use u64 at
places where you know that 64 bit address is always necessary.
Let's use u64 instead for mips.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
dma64_addr_t looks pointless (at least there is no point that an
architecture has the own dma64_addr_t typedef).
dma_addr_t is set to 32 or 64 bits appropriately. You can use u64
at places where you know that 64 bit address is always necessary.
Let's use u64 instead for sparc32.
Looks like PCI654_REQUIRED_MASK or PCI64_ADR_BASE isn't used. They can
be removed?
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: David Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Replace iterated page_cache_release() with release_pages(), which is
faster and shorter.
Needs release_pages() to be exported to modules.
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The taskstats interface uses microsecond granularity for the user and
system time values. The conversion from cputime to the taskstats values
uses the cputime_to_msecs primitive which effectively limits the
granularity to milliseconds. Add the cputime_to_usecs primitive for
architectures that have better, more precise CPU time values. Remove
cputime_to_msecs primitive because there are no more users left.
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Luck Tony <tony.luck@intel.com>
Cc: Shailabh Nagar <nagar1234@in.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Shailabh Nagar <nagar@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Separate the finding of a task_struct by pid or tgid from filling the
taskstats data. This makes the code more readable.
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Move each taskstats command into a single function. This makes the code
more readable and makes it easier to add new commands.
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
prepare_reply() sets up an skb for the response. The payload contains:
+--------------------------------+
| genlmsghdr - 4 bytes |
+--------------------------------+
| NLA header - 4 bytes | /* Aggregate header */
+-+------------------------------+
| | NLA header - 4 bytes | /* PID header */
| +------------------------------+
| | pid/tgid - 4 bytes |
| +------------------------------+
| | NLA header - 4 bytes | /* stats header */
| + -----------------------------+ <- oops. aligned on 4 byte boundary
| | struct taskstats - 328 bytes |
+-+------------------------------+
The start of the taskstats struct must be 8 byte aligned on IA64 (and
other systems with 8 byte alignment rules for 64-bit types) or runtime
alignment warnings will be issued.
This patch pads the pid/tgid field out to sizeof(long), which forces the
alignment of taskstats. The getdelays userspace code is ok with this
since it assumes 32-bit pid/tgid and then honors that header's length
field.
An array is used to avoid exposing kernel memory contents to userspace in
the response.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Task delay-accounting was identified as one means of determining how long
a process spends in congestion_wait() without adding new statistics. For
example, if the workload should not be doing IO, delay-accounting could
reveal how long it was spending in unexpected IO or delays.
Unfortunately, on closer examination it was clear that getdelays does not
act as documented.
Commit a3baf649 ("per-task-delay-accounting: documentation") added
Documentation/accounting/getdelays.c with a -c switch that was documented
to fork/exec a child and report statistics on it but for reasons that are
unclear to me, commit 9e06d3f9 deleted support for this switch but did not
update the documentation. It might be an oversight or it might be because
the control flow of the program meant that accounting information would be
printed once early in the lifetime of the program making it of limited
use.
This patch reimplements -c for getdelays.c to act as documented. Unlike
the original version, it waits until the command completes before printing
any information on it. An example of it being used looks like
$ ./getdelays -d -c find /home/mel -name mel
print delayacct stats ON
/home/mel
/home/mel/.notes-wine/drive_c/windows/profiles/mel
/home/mel/.wine/drive_c/windows/profiles/mel
/home/mel/git-configs/dot.kde/share/apps/konqueror/home/mel
PID 5923
CPU count real total virtual total delay total
42779 5051232096 5164722692 564207988
IO count delay total
41727 97804147758
SWAP count delay total
0 0
RECLAIM count delay total
0 0
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We have the namespaces as a menuconfig like the cgroup. The cgroup and
the namespace are two base bricks for the containers.
It is more logical to put the namespace menu right after the cgroup menu.
Signed-off-by: Daniel Lezcano <daniel.lezcano@free.fr>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: "Serge E. Hallyn" <serue@us.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This subsystem is merged since a long time now, I think we can consider it
mature enough.
Signed-off-by: Daniel Lezcano <daniel.lezcano@free.fr>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: "Serge E. Hallyn" <serue@us.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The different cgroup subsystems are under the cgroup submenu. The
dependency between the cgroups and the menu subsystems is pointless.
Signed-off-by: Daniel Lezcano <daniel.lezcano@free.fr>
Acked-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: "Serge E. Hallyn" <serue@us.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Make the namespaces config option a submenu.
Signed-off-by: Daniel Lezcano <daniel.lezcano@free.fr>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: "Serge E. Hallyn" <serue@us.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
