The find_group_flex() inode allocator is now only used if the
filesystem is mounted using the "oldalloc" mount option. It is
replaced with the original Orlov allocator that has been updated for
flex_bg filesystems (it should behave the same way if flex_bg is
disabled). The inode allocator now functions by taking into account
each flex_bg group, instead of each block group, when deciding whether
or not it's time to allocate a new directory into a fresh flex_bg.
The block allocator has also been changed so that the first block
group in each flex_bg is preferred for use for storing directory
blocks. This keeps directory blocks close together, which is good for
speeding up e2fsck since large directories are more likely to look
like this:
debugfs: stat /home/tytso/Maildir/cur
Inode: 1844562 Type: directory Mode: 0700 Flags: 0x81000
Generation: 1132745781 Version: 0x00000000:0000ad71
User: 15806 Group: 15806 Size: 1060864
File ACL: 0 Directory ACL: 0
Links: 2 Blockcount: 2072
Fragment: Address: 0 Number: 0 Size: 0
ctime: 0x499c0ff4:164961f4 -- Wed Feb 18 08:41:08 2009
atime: 0x499c0ff4:00000000 -- Wed Feb 18 08:41:08 2009
mtime: 0x49957f51:00000000 -- Fri Feb 13 09:10:25 2009
crtime: 0x499c0f57:00d51440 -- Wed Feb 18 08:38:31 2009
Size of extra inode fields: 28
BLOCKS:
(0):7348651, (1-258):7348654-7348911
TOTAL: 259
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Functions ext4_write_begin() and ext4_da_write_begin() call
grab_cache_page_write_begin() without AOP_FLAG_NOFS. Thus it
can happen that page reclaim is triggered in that function
and it recurses back into the filesystem (or some other filesystem).
But this can lead to various problems as a transaction is already
started at that point. Add the necessary flag.
http://bugzilla.kernel.org/show_bug.cgi?id=11688
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This is a workaround for find_group_flex() which badly needs to be
replaced. One of its problems (besides ignoring the Orlov algorithm)
is that it is a bit hyperactive about returning failure under
suspicious circumstances. This can lead to spurious ENOSPC failures
even when there are inodes still available.
Work around this for now by retrying the search using
find_group_other() if find_group_flex() returns -1. If
find_group_other() succeeds when find_group_flex() has failed, log a
warning message.
A better block/inode allocator that will fix this problem for real has
been queued up for the next merge window.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6:
[CIFS] Fix multiuser mounts so server does not invalidate earlier security contexts
[CIFS] improve posix semantics of file create
[CIFS] Fix oops in cifs_strfromUCS_le mounting to servers which do not specify their OS
cifs: posix fill in inode needed by posix open
cifs: properly handle case where CIFSGetSrvInodeNumber fails
cifs: refactor new_inode() calls and inode initialization
[CIFS] Prevent OOPs when mounting with remote prefixpath.
[CIFS] ipv6_addr_equal for address comparison
At scan time we observed following scenario:
node A inserted
node B inserted
node C inserted -> sets overlapped flag on node B
node A is removed due to CRC failure -> overlapped flag on node B remains
while (tn->overlapped)
tn = tn_prev(tn);
==> crash, when tn_prev(B) is referenced.
When the ultimate node is removed at scan time and the overlapped flag
is set on the penultimate node, then nothing updates the overlapped
flag of that node. The overlapped iterators blindly expect that the
ultimate node does not have the overlapped flag set, which causes the
scan code to crash.
It would be a huge overhead to go through the node chain on node
removal and fix up the overlapped flags, so detecting such a case on
the fly in the overlapped iterators is a simpler and reliable
solution.
Cc: stable@kernel.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
When two different users mount the same Windows 2003 Server share using CIFS,
the first session mounted can be invalidated. Some servers invalidate the first
smb session when a second similar user (e.g. two users who get mapped by server to "guest")
authenticates an smb session from the same client.
By making sure that we set the 2nd and subsequent vc numbers to nonzero values,
this ensures that we will not have this problem.
Fixes Samba bug 6004, problem description follows:
How to reproduce:
- configure an "open share" (full permissions to Guest user) on Windows 2003
Server (I couldn't reproduce the problem with Samba server or Windows older
than 2003)
- mount the share twice with different users who will be authenticated as guest.
noacl,noperm,user=john,dir_mode=0700,domain=DOMAIN,rw
noacl,noperm,user=jeff,dir_mode=0700,domain=DOMAIN,rw
Result:
- just the mount point mounted last is accessible:
Signed-off-by: Steve French <sfrench@us.ibm.com>
Samba server added support for a new posix open/create/mkdir operation
a year or so ago, and we added support to cifs for mkdir to use it,
but had not added the corresponding code to file create.
The following patch helps improve the performance of the cifs create
path (to Samba and servers which support the cifs posix protocol
extensions). Using Connectathon basic test1, with 2000 files, the
performance improved about 15%, and also helped reduce network traffic
(17% fewer SMBs sent over the wire) due to saving a network round trip
for the SetPathInfo on every file create.
It should also help the semantics (and probably the performance) of
write (e.g. when posix byte range locks are on the file) on file
handles opened with posix create, and adds support for a few flags
which would have to be ignored otherwise.
Signed-off-by: Steve French <sfrench@us.ibm.com>
Fixes kernel bug #10451http://bugzilla.kernel.org/show_bug.cgi?id=10451
Certain NAS appliances do not set the operating system or network operating system
fields in the session setup response on the wire. cifs was oopsing on the unexpected
zero length response fields (when trying to null terminate a zero length field).
This fixes the oops.
Acked-by: Jeff Layton <jlayton@redhat.com>
CC: stable <stable@kernel.org>
Signed-off-by: Steve French <sfrench@us.ibm.com>
...if it does then we pass a pointer to an unintialized variable for
the inode number to cifs_new_inode. Have it pass a NULL pointer instead.
Also tweak the function prototypes to reduce the amount of casting.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Move new inode creation into a separate routine and refactor the
callers to take advantage of it.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Fixes OOPs with message 'kernel BUG at fs/cifs/cifs_dfs_ref.c:274!'.
Checks if the prefixpath in an accesible while we are still in cifs_mount
and fails with reporting a error if we can't access the prefixpath
Should fix Samba bugs 6086 and 5861 and kernel bug 12192
Signed-off-by: Igor Mammedov <niallain@gmail.com>
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
This fixes a problem where we could return -ENOSPC when we may actually have
plenty of space, the space is just pinned. Instead of returning -ENOSPC
immediately, commit the transaction first and then try and do the allocation
again.
This patch also does chunk allocation for metadata if we pass the 80%
threshold for metadata space. This will help with stack usage since the chunk
allocation will happen early on, instead of when the allocation is happening.
Signed-off-by: Josef Bacik <jbacik@redhat.com>
This is a step in the direction of better -ENOSPC handling. Instead of
checking the global bytes counter we check the space_info bytes counters to
make sure we have enough space.
If we don't we go ahead and try to allocate a new chunk, and then if that fails
we return -ENOSPC. This patch adds two counters to btrfs_space_info,
bytes_delalloc and bytes_may_use.
bytes_delalloc account for extents we've actually setup for delalloc and will
be allocated at some point down the line.
bytes_may_use is to keep track of how many bytes we may use for delalloc at
some point. When we actually set the extent_bit for the delalloc bytes we
subtract the reserved bytes from the bytes_may_use counter. This keeps us from
not actually being able to allocate space for any delalloc bytes.
Signed-off-by: Josef Bacik <jbacik@redhat.com>
This reverts commit d2859751cd.
This commit caused regression. We'll try to fix use of new
vmap API for next release.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Felix Blyakher <felixb@sgi.com>
This reverts commit 95f8e302c0.
This commit caused regression. We'll try to fix use of new
vmap API for next release.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Felix Blyakher <felixb@sgi.com>
* 'for-linus' of git://git.kernel.dk/linux-2.6-block:
block: fix deadlock in blk_abort_queue() for drivers that readd to timeout list
block: fix booting from partitioned md array
block: revert part of 18ce3751cc
cciss: PCI power management reset for kexec
paride/pg.c: xs(): &&/|| confusion
fs/bio: bio_alloc_bioset: pass right object ptr to mempool_free
block: fix bad definition of BIO_RW_SYNC
bsg: Fix sense buffer bug in SG_IO
Li Zefan said:
Thread 1:
for ((; ;))
{
mount -t cpuset xxx /mnt > /dev/null 2>&1
cat /mnt/cpus > /dev/null 2>&1
umount /mnt > /dev/null 2>&1
}
Thread 2:
for ((; ;))
{
mount -t cpuset xxx /mnt > /dev/null 2>&1
umount /mnt > /dev/null 2>&1
}
(Note: It is irrelevant which cgroup subsys is used.)
After a while a lockdep warning showed up:
=============================================
[ INFO: possible recursive locking detected ]
2.6.28 #479
---------------------------------------------
mount/13554 is trying to acquire lock:
(&type->s_umount_key#19){--..}, at: [<c049d888>] sget+0x5e/0x321
but task is already holding lock:
(&type->s_umount_key#19){--..}, at: [<c049da0c>] sget+0x1e2/0x321
other info that might help us debug this:
1 lock held by mount/13554:
#0: (&type->s_umount_key#19){--..}, at: [<c049da0c>] sget+0x1e2/0x321
stack backtrace:
Pid: 13554, comm: mount Not tainted 2.6.28-mc #479
Call Trace:
[<c044ad2e>] validate_chain+0x4c6/0xbbd
[<c044ba9b>] __lock_acquire+0x676/0x700
[<c044bb82>] lock_acquire+0x5d/0x7a
[<c049d888>] ? sget+0x5e/0x321
[<c061b9b8>] down_write+0x34/0x50
[<c049d888>] ? sget+0x5e/0x321
[<c049d888>] sget+0x5e/0x321
[<c045a2e7>] ? cgroup_set_super+0x0/0x3e
[<c045959f>] ? cgroup_test_super+0x0/0x2f
[<c045bcea>] cgroup_get_sb+0x98/0x2e7
[<c045cfb6>] cpuset_get_sb+0x4a/0x5f
[<c049dfa4>] vfs_kern_mount+0x40/0x7b
[<c049e02d>] do_kern_mount+0x37/0xbf
[<c04af4a0>] do_mount+0x5c3/0x61a
[<c04addd2>] ? copy_mount_options+0x2c/0x111
[<c04af560>] sys_mount+0x69/0xa0
[<c0403251>] sysenter_do_call+0x12/0x31
The cause is after alloc_super() and then retry, an old entry in list
fs_supers is found, so grab_super(old) is called, but both functions hold
s_umount lock:
struct super_block *sget(...)
{
...
retry:
spin_lock(&sb_lock);
if (test) {
list_for_each_entry(old, &type->fs_supers, s_instances) {
if (!test(old, data))
continue;
if (!grab_super(old)) <--- 2nd: down_write(&old->s_umount);
goto retry;
if (s)
destroy_super(s);
return old;
}
}
if (!s) {
spin_unlock(&sb_lock);
s = alloc_super(type); <--- 1th: down_write(&s->s_umount)
if (!s)
return ERR_PTR(-ENOMEM);
goto retry;
}
...
}
It seems like a false positive, and seems like VFS but not cgroup needs to
be fixed.
Peter said:
We can simply put the new s_umount instance in a but lockdep doesn't
particularly cares about subclass order.
If there's any issue with the callers of sget() assuming the s_umount lock
being of sublcass 0, then there is another annotation we can use to fix
that, but lets not bother with that if this is sufficient.
Addresses http://bugzilla.kernel.org/show_bug.cgi?id=12673
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Tested-by: Li Zefan <lizf@cn.fujitsu.com>
Reported-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Paul Menage <menage@google.com>
Cc: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
YAMAMOTO-san noticed that task_dirty_inc doesn't seem to be called properly for
cases where set_page_dirty is not used to dirty a page (eg. mark_buffer_dirty).
Additionally, there is some inconsistency about when task_dirty_inc is
called. It is used for dirty balancing, however it even gets called for
__set_page_dirty_no_writeback.
So rather than increment it in a set_page_dirty wrapper, move it down to
exactly where the dirty page accounting stats are incremented.
Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Signed-off-by: Nick Piggin <npiggin@suse.de>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
As requested by Michael, add a missing check for valid flags in
timerfd_settime(), and make it return EINVAL in case some extra bits are
set.
Michael said:
If this is to be any use to userland apps that want to check flag
support (perhaps it is too late already), then the sooner we get it
into the kernel the better: 2.6.29 would be good; earlier stables as
well would be even better.
[akpm@linux-foundation.org: remove unused TFD_FLAGS_SET]
Acked-by: Michael Kerrisk <mtk.manpages@gmail.com>
Signed-off-by: Davide Libenzi <davidel@xmailserver.org>
Cc: <stable@kernel.org> [2.6.27.x, 2.6.28.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently seq_read assumes that the offset passed to it is always the
offset it passed to user space. In the case pread this assumption is
broken and we do the wrong thing when presented with pread.
To solve this I introduce an offset cache inside of struct seq_file so we
know where our logical file position is. Then in seq_read if we try to
read from another offset we reset our data structures and attempt to go to
the offset user space wanted.
[akpm@linux-foundation.org: restore FMODE_PWRITE]
[pjt@google.com: seq_open needs its fmode opened up to take advantage of this]
Signed-off-by: Eric Biederman <ebiederm@xmission.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Paul Turner <pjt@google.com>
Cc: <stable@kernel.org> [2.6.25.x, 2.6.26.x, 2.6.27.x, 2.6.28.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This reverts commit d2859751cd.
This commit caused regression. We'll try to fix use of new
vmap API for next release.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Felix Blyakher <felixb@sgi.com>
This reverts commit 95f8e302c0.
This commit caused regression. We'll try to fix use of new
vmap API for next release.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Felix Blyakher <felixb@sgi.com>
The above commit added WRITE_SYNC and switched various places to using
that for committing writes that will be waited upon immediately after
submission. However, this causes a performance regression with AS and CFQ
for ext3 at least, since sync_dirty_buffer() will submit some writes with
WRITE_SYNC while ext3 has sumitted others dependent writes without the sync
flag set. This causes excessive anticipation/idling in the IO scheduler
because sync and async writes get interleaved, causing a big performance
regression for the below test case (which is meant to simulate sqlite
like behaviour).
---- test case ----
int main(int argc, char **argv)
{
int fdes, i;
FILE *fp;
struct timeval start;
struct timeval end;
struct timeval res;
gettimeofday(&start, NULL);
for (i=0; i<ROWS; i++) {
fp = fopen("test_file", "a");
fprintf(fp, "Some Text Data\n");
fdes = fileno(fp);
fsync(fdes);
fclose(fp);
}
gettimeofday(&end, NULL);
timersub(&end, &start, &res);
fprintf(stdout, "time to write %d lines is %ld(msec)\n", ROWS,
(res.tv_sec*1000000 + res.tv_usec)/1000);
return 0;
}
-------------------
Thanks to Sean.White@APCC.com for tracking down this performance
regression and providing a test case.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
When freeing from bio pool use right ptr to account for bs->front_pad,
instead of bio ptr,
Signed-off-by: Subhash Peddamallu <subhash.peddamallu@gmail.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable:
Btrfs: hold trans_mutex when using btrfs_record_root_in_trans
Btrfs: make a lockdep class for the extent buffer locks
Btrfs: fs/btrfs/volumes.c: remove useless kzalloc
Btrfs: remove unused code in split_state()
Btrfs: remove btrfs_init_path
Btrfs: balance_level checks !child after access
Btrfs: Avoid using __GFP_HIGHMEM with slab allocator
Btrfs: don't clean old snapshots on sync(1)
Btrfs: use larger metadata clusters in ssd mode
Btrfs: process mount options on mount -o remount,
Btrfs: make sure all pending extent operations are complete
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
ext4: Fix NULL dereference in ext4_ext_migrate()'s error handling
ext4: Implement range_cyclic in ext4_da_writepages instead of write_cache_pages
ext4: Initialize preallocation list_head's properly
ext4: Fix lockdep warning
ext4: Fix to read empty directory blocks correctly in 64k
jbd2: Avoid possible NULL dereference in jbd2_journal_begin_ordered_truncate()
Revert "ext4: wait on all pending commits in ext4_sync_fs()"
jbd2: Fix return value of jbd2_journal_start_commit()
Getting this wrong caused
WARNING: at fs/namespace.c:636 mntput_no_expire+0xac/0xf2()
due to optimistically checking cpu_writer->mnt outside the spinlock.
Here's what we really want:
* we know that nobody will set cpu_writer->mnt to mnt from now on
* all changes to that sucker are done under cpu_writer->lock
* we want the laziest equivalent of
spin_lock(&cpu_writer->lock);
if (likely(cpu_writer->mnt != mnt)) {
spin_unlock(&cpu_writer->lock);
continue;
}
/* do stuff */
that would make sure we won't miss earlier setting of ->mnt done by
another CPU.
Anyway, for now we just move the spin_lock() earlier and move the test
into the properly locked region.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Reported-and-tested-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Trivial cleanup, list_del(); list_add{,_tail}() is equivalent
to list_move{,_tail}(). Semantic patch for coccinelle can be
found at www.cccmz.de/~snakebyte/list_move_tail.spatch
Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
This was found through a code checker (http://repo.or.cz/w/smatch.git/).
It looks like you might be able to trigger the error by trying to migrate
a readonly file system.
Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
At the moment there are few restrictions on which flags may be set on
which inodes. Specifically DIRSYNC may only be set on directories and
IMMUTABLE and APPEND may not be set on links. Tighten that to disallow
TOPDIR being set on non-directories and only NODUMP and NOATIME to be set
on non-regular file, non-directories.
Introduces a flags masking function which masks flags based on mode and
use it during inode creation and when flags are set via the ioctl to
facilitate future consistency.
Signed-off-by: Duane Griffin <duaneg@dghda.com>
Acked-by: Andreas Dilger <adilger@sun.com>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
At present INDEX and EXTENTS are the only flags that new ext4 inodes do
NOT inherit from their parent. In addition prevent the flags DIRTY,
ECOMPR, IMAGIC, TOPDIR, HUGE_FILE and EXT_MIGRATE from being inherited.
List inheritable flags explicitly to prevent future flags from
accidentally being inherited.
This fixes the TOPDIR flag inheritance bug reported at
http://bugzilla.kernel.org/show_bug.cgi?id=9866.
Signed-off-by: Duane Griffin <duaneg@dghda.com>
Acked-by: Andreas Dilger <adilger@sun.com>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
As spotted by kmemtrace, struct ext4_sb_info is 17664 bytes on 64-bit
which makes it a very bad fit for SLAB allocators. The culprit of the
wasted memory is ->s_blockgroup_lock which can be as big as 16 KB when
NR_CPUS >= 32.
To fix that, allocate ->s_blockgroup_lock, which fits nicely in a order 2
page in the worst case, separately. This shinks down struct ext4_sb_info
enough to fit a 2 KB slab cache so now we allocate 16 KB + 2 KB instead of
32 KB saving 14 KB of memory.
Acked-by: Andreas Dilger <adilger@sun.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
The rec_len field in the directory entry is 16 bits, so to encode
blocksizes larger than 64k becomes problematic. This patch allows us
to supprot block sizes up to 256k, by using the low 2 bits to extend
the range of rec_len to 2**18-1 (since valid rec_len sizes must be a
multiple of 4). We use the convention that a rec_len of 0 or 65535
means the filesystem block size, for compatibility with older kernels.
It's unlikely we'll see VM pages of up to 256k, but at some point we
might find that the Linux VM has been enhanced to support filesystem
block sizes > than the VM page size, at which point it might be useful
for some applications to allow very large filesystem block sizes.
Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
With delayed allocation we lock the page in write_cache_pages() and
try to build an in memory extent of contiguous blocks. This is needed
so that we can get large contiguous blocks request. If range_cyclic
mode is enabled, write_cache_pages() will loop back to the 0 index if
no I/O has been done yet, and try to start writing from the beginning
of the range. That causes an attempt to take the page lock of lower
index page while holding the page lock of higher index page, which can
cause a dead lock with another writeback thread.
The solution is to implement the range_cyclic behavior in
ext4_da_writepages() instead.
http://bugzilla.kernel.org/show_bug.cgi?id=12579
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
When creating a new ext4_prealloc_space structure, we have to
initialize its list_head pointers before we add them to any prealloc
lists. Otherwise, with list debug enabled, we will get list
corruption warnings.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
I've noticed some pretty poor behavior on OLPC machines after bootup, when
gdm/X are starting. The GCD monopolizes the scheduler (which in turns
means it gets to do more nand i/o), which results in processes taking much
much longer than they should to start.
As an example, on an OLPC machine going from OFW to a usable X (via
auto-login gdm) takes 2m 30s. The majority of this time is consumed by
the switch into graphical mode. With this patch, we cut a full 60s off of
bootup time. After bootup, things are much snappier as well.
Note that we have seen a CRC node error with this patch that causes the machine
to fail to boot, but we've also seen that problem without this patch.
Signed-off-by: Andres Salomon <dilinger@debian.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
