Clean up and optimize cpumask_of_cpu(), by sharing all the zero words.
Instead of stupidly generating all possible i=0...NR_CPUS 2^i patterns
creating a huge array of constant bitmasks, realize that the zero words
can be shared.
In other words, on a 64-bit architecture, we only ever need 64 of these
arrays - with a different bit set in one single world (with enough zero
words around it so that we can create any bitmask by just offsetting in
that big array). And then we just put enough zeroes around it that we
can point every single cpumask to be one of those things.
So when we have 4k CPU's, instead of having 4k arrays (of 4k bits each,
with one bit set in each array - 2MB memory total), we have exactly 64
arrays instead, each 8k bits in size (64kB total).
And then we just point cpumask(n) to the right position (which we can
calculate dynamically). Once we have the right arrays, getting
"cpumask(n)" ends up being:
static inline const cpumask_t *get_cpu_mask(unsigned int cpu)
{
const unsigned long *p = cpu_bit_bitmap[1 + cpu % BITS_PER_LONG];
p -= cpu / BITS_PER_LONG;
return (const cpumask_t *)p;
}
This brings other advantages and simplifications as well:
- we are not wasting memory that is just filled with a single bit in
various different places
- we don't need all those games to re-create the arrays in some dense
format, because they're already going to be dense enough.
if we compile a kernel for up to 4k CPU's, "wasting" that 64kB of memory
is a non-issue (especially since by doing this "overlapping" trick we
probably get better cache behaviour anyway).
[ mingo@elte.hu:
Converted Linus's mails into a commit. See:
http://lkml.org/lkml/2008/7/27/156http://lkml.org/lkml/2008/7/28/320
Also applied a family filter - which also has the side-effect of leaving
out the bits where Linus calls me an idio... Oh, never mind ;-)
]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (25 commits)
powerpc: Disable 64K hugetlb support when doing 64K SPU mappings
powerpc/powermac: Fixup default serial port device for pmac_zilog
powerpc/powermac: Use sane default baudrate for SCC debugging
powerpc/mm: Implement _PAGE_SPECIAL & pte_special() for 64-bit
powerpc: Show processor cache information in sysfs
powerpc: Make core id information available to userspace
powerpc: Make core sibling information available to userspace
powerpc/vio: More fallout from dma_mapping_error API change
ibmveth: Fix multiple errors with dma_mapping_error conversion
powerpc/pseries: Fix CMO sysdev attribute API change fallout
powerpc: Enable tracehook for the architecture
powerpc: Add TIF_NOTIFY_RESUME support for tracehook
powerpc: Add asm/syscall.h with the tracehook entry points
powerpc: Make syscall tracing use tracehook.h helpers
powerpc: Call tracehook_signal_handler() when setting up signal frames
powerpc: Update cpu_sibling_maps dynamically
powerpc: register_cpu_online should be __cpuinit
powerpc: kill useless SMT code in prom_hold_cpus
powerpc: Fix 8xx build failure
powerpc: Fix vio build warnings
...
* git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6: (72 commits)
sh: SuperH Mobile CEU and camera platform data for AP325RXA
sh: Update smc911x platform data for AP325RXA
sh: SuperH Mobile LCDC platform data for AP325RXA
sh: Add SuperH Mobile CEU platform data for Migo-R
sh: Add SuperH Mobile LCDC platform data for Migo-R
sh: Move asid_cache() out of ifdef to fix SH-3/4 nommu build.
sh: Workaround for __put_user_asm() bug with gcc 4.x on big-endian.
sh: Wire up new syscalls.
sh: fix uImage Entry Point
sh_keysc: remove request_mem_region() and release_mem_region()
sh: Don't miss pending signals returning to user mode after signal processing
sh: Use clk_always_enable() on sh7366
sh: Use clk_always_enable() on sh7343 / SE77343
sh: Use clk_always_enable() on sh7722 / Migo-R / SE7722
sh: Use clk_always_enable() on sh7723 / ap325rxa
sh: Introduce clk_always_enable() function
sh: Show all clocks and their state in /proc/clocks
sh: Merge sh7343 and sh7722 clock code
sh: Add SuperH Mobile MSTPCR bits to clock framework
sh: Use arch_flags to simplify sh7722 siu clock code
...
The connect and disconnect functions are unnecessary - everything they do can be
accomplished in the initial probe - so remove them.
Signed-off-by: Adrian McMenamin <adrian@mcmen.demon.co.uk>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Instead of a "cpu" arg with magic values NR_CPUS (any cpu) and ~0 (all
cpus), pass a cpumask_t. Allow NULL for the common case (where we
don't care which CPU the function is run on): temporary cpumask_t's
are usually considered bad for stack space.
This deprecates stop_machine_run, to be removed soon when all the
callers are dead.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
stop_machine creates a kthread which creates kernel threads. We can
create those threads directly and simplify things a little. Some care
must be taken with CPU hotunplug, which has special needs, but that code
seems more robust than it was in the past.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
-allow stop_mahcine_run() to call a function on all cpus. Calling
stop_machine_run() with a 'ALL_CPUS' invokes this new behavior.
stop_machine_run() proceeds as normal until the calling cpu has
invoked 'fn'. Then, we tell all the other cpus to call 'fn'.
Signed-off-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
CC: Adrian Bunk <bunk@stusta.de>
CC: Andi Kleen <andi@firstfloor.org>
CC: Alexey Dobriyan <adobriyan@gmail.com>
CC: Christoph Hellwig <hch@infradead.org>
CC: mingo@elte.hu
CC: akpm@osdl.org
Simplify the code of include/linux/task_io_accounting.h.
It is also more reasonable to have all the task i/o-related statistics in a
single struct (task_io_accounting).
Signed-off-by: Andrea Righi <righi.andrea@gmail.com>
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6:
firewire: state userland requirements in Kconfig help
firewire: avoid memleak after phy config transmit failure
firewire: fw-ohci: TSB43AB22/A dualbuffer workaround
firewire: queue the right number of data
firewire: warn on unfinished transactions during card removal
firewire: small fw_fill_request cleanup
firewire: fully initialize fw_transaction before marking it pending
firewire: fix race of bus reset with request transmission
Put all i/o statistics in struct proc_io_accounting and use inline functions to
initialize and increment statistics, removing a lot of single variable
assignments.
This also reduces the kernel size as following (with CONFIG_TASK_XACCT=y and
CONFIG_TASK_IO_ACCOUNTING=y).
text data bss dec hex filename
11651 0 0 11651 2d83 kernel/exit.o.before
11619 0 0 11619 2d63 kernel/exit.o.after
10886 132 136 11154 2b92 kernel/fork.o.before
10758 132 136 11026 2b12 kernel/fork.o.after
3082029 807968 4818600 8708597 84e1f5 vmlinux.o.before
3081869 807968 4818600 8708437 84e155 vmlinux.o.after
Signed-off-by: Andrea Righi <righi.andrea@gmail.com>
Acked-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The VID_TYPE defines are V4L1 specific, so copy them back to videodev.h.
In videodev2.h ensure that they are not used in the kernel (you need
to include videodev.h instead) and mark them are deprecated.
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
SPCA505 and SPCA508 added in the pixel formats.
Decode functions and associated resources removed in spca505, 506 and 508.
The decode routines are now found in the V4L library.
Signed-off-by: Jean-Francois Moine <moinejf@free.fr>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/roland/infiniband:
mlx4: Update/add Mellanox Technologies copyright lines to mlx4 driver files
mlx4_core: Add VLAN tag field to WQE control segment struct
RDMA/nes: CM connection setup/teardown rework
IPoIB: Correct help text for INFINIBAND_IPOIB_DEBUG
IPoIB/cm: Connected mode is no longer EXPERIMENTAL
RDMA/ucm: BKL is not needed for ib_ucm_open()
RDMA/ucma: BKL is not needed for ucma_open()
* git://git.infradead.org/mtd-2.6: (57 commits)
[MTD] [NAND] subpage read feature as a way to increase performance.
CPUFREQ: S3C24XX NAND driver frequency scaling support.
[MTD][NAND] au1550nd: remove unused variable
[MTD] jedec_probe: Fix SST 16-bit chip detection
[MTD][MTDPART] Fix a division by zero bug
[MTD][MTDPART] Cleanup and document the erase region handling
[MTD][MTDPART] Handle most checkpatch findings
[MTD][MTDPART] Seperate main loop from per-partition code in add_mtd_partition
[MTD] physmap: resume already suspended chips on failure to suspend
[MTD] physmap: Fix suspend/resume/shutdown bugs.
[MTD] [NOR] Fix -ETIMEO errors in CFI driver
[MTD] [NAND] fsl_elbc_nand: fix section mismatch with CONFIG_MTD_OF_PARTS=y
[JFFS2] Use .unlocked_ioctl
[MTD] Fix const assignment in the MTD command line partitioning driver
[MTD] [NOR] gen_probe: No debug message when debugging is disabled
[MTD] [NAND] remove __PPC__ hardcoded address from DiskOnChip drivers
[MTD] [MAPS] Remove the bast-flash driver.
[MTD] [NAND] fsl_elbc_nand: ecclayout cleanups
[MTD] [NAND] fsl_elbc_nand: implement support for flash-based BBT
[MTD] [NAND] fsl_elbc_nand: fix OOB workability for large page NAND chips
...
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/drzeus/mmc:
atmel-mci: debugfs support
mmc: Add per-card debugfs support
mmc: Export internal host state through debugfs
imxmmc: fix crash when no platform data is provided
imxmmc: fix platform resources
imxmmc: remove DEBUG definition
mmc_spi: put signals to low power off fix
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (39 commits)
[PATCH] fix RLIM_NOFILE handling
[PATCH] get rid of corner case in dup3() entirely
[PATCH] remove remaining namei_{32,64}.h crap
[PATCH] get rid of indirect users of namei.h
[PATCH] get rid of __user_path_lookup_open
[PATCH] f_count may wrap around
[PATCH] dup3 fix
[PATCH] don't pass nameidata to __ncp_lookup_validate()
[PATCH] don't pass nameidata to gfs2_lookupi()
[PATCH] new (local) helper: user_path_parent()
[PATCH] sanitize __user_walk_fd() et.al.
[PATCH] preparation to __user_walk_fd cleanup
[PATCH] kill nameidata passing to permission(), rename to inode_permission()
[PATCH] take noexec checks to very few callers that care
Re: [PATCH 3/6] vfs: open_exec cleanup
[patch 4/4] vfs: immutable inode checking cleanup
[patch 3/4] fat: dont call notify_change
[patch 2/4] vfs: utimes cleanup
[patch 1/4] vfs: utimes: move owner check into inode_change_ok()
[PATCH] vfs: use kstrdup() and check failing allocation
...
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6:
netns: fix ip_rt_frag_needed rt_is_expired
netfilter: nf_conntrack_extend: avoid unnecessary "ct->ext" dereferences
netfilter: fix double-free and use-after free
netfilter: arptables in netns for real
netfilter: ip{,6}tables_security: fix future section mismatch
selinux: use nf_register_hooks()
netfilter: ebtables: use nf_register_hooks()
Revert "pkt_sched: sch_sfq: dump a real number of flows"
qeth: use dev->ml_priv instead of dev->priv
syncookies: Make sure ECN is disabled
net: drop unused BUG_TRAP()
net: convert BUG_TRAP to generic WARN_ON
drivers/net: convert BUG_TRAP to generic WARN_ON
Remove the following warning when CONFIG_HUGETLB_PAGE is not set:
ipc/shm.c: In function `shm_get_stat':
ipc/shm.c:565: warning: unused variable `h'
[akpm@linux-foundation.org: use tabs, not spaces]
Signed-off-by: Andrea Righi <righi.andrea@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fs.h needs path.h, not namei.h; nfs_fs.h doesn't need it at all.
Several places in the tree needed direct include.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
make it atomic_long_t; while we are at it, get rid of useless checks in affs,
hfs and hpfs - ->open() always has it equal to 1, ->release() - to 0.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* do not pass nameidata; struct path is all the callers want.
* switch to new helpers:
user_path_at(dfd, pathname, flags, &path)
user_path(pathname, &path)
user_lpath(pathname, &path)
user_path_dir(pathname, &path) (fail if not a directory)
The last 3 are trivial macro wrappers for the first one.
* remove nameidata in callers.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Add a new ia_valid flag: ATTR_TIMES_SET, to handle the
UTIMES_OMIT/UTIMES_NOW and UTIMES_NOW/UTIMES_OMIT cases. In these
cases neither ATTR_MTIME_SET nor ATTR_ATIME_SET is in the flags, yet
the POSIX draft specifies that permission checking is performed the
same way as if one or both of the times was explicitly set to a
timestamp.
See the path "vfs: utimensat(): fix error checking for
{UTIME_NOW,UTIME_OMIT} case" by Michael Kerrisk for the patch
introducing this behavior.
This is a cleanup, as well as allowing filesystems (NFS/fuse/...) to
perform their own permission checking instead of the default.
CC: Ulrich Drepper <drepper@redhat.com>
CC: Michael Kerrisk <mtk.manpages@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
- use kstrdup() instead of kmalloc() + memcpy()
- return NULL if allocating ->mnt_devname failed
- mnt_devname should be const
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Cyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* MAY_CHDIR is redundant - it's an equivalent of MAY_ACCESS
* MAY_ACCESS on fuse should affect only the last step of pathname resolution
* fchdir() and chroot() should pass MAY_ACCESS, for the same reason why
chdir() needs that.
* now that we pass MAY_ACCESS explicitly in all cases, LOOKUP_ACCESS can be
removed; it has no business being in nameidata.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
... so we ought to pass MAY_CHDIR to vfs_permission() instead of having
it triggered on every step of preceding pathname resolution. LOOKUP_CHDIR
is killed by that.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Remove the unused mode parameter from vfs_symlink and callers.
Thanks to Tetsuo Handa for noticing.
CC: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
All calls to remove_suid() are made with a file pointer, because
(similarly to file_update_time) it is called when the file is written.
Clean up callers by passing in a file instead of a dentry.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
* kill nameidata * argument; map the 3 bits in ->flags anybody cares
about to new MAY_... ones and pass with the mask.
* kill redundant gfs2_iop_permission()
* sanitize ecryptfs_permission()
* fix remaining places where ->permission() instances might barf on new
MAY_... found in mask.
The obvious next target in that direction is permission(9)
folded fix for nfs_permission() breakage from Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* keep references to ctl_table_head and ctl_table in /proc/sys inodes
* grab the former during operations, use the latter for access to
entry if that succeeds
* have ->d_compare() check if table should be seen for one who does lookup;
that allows us to avoid flipping inodes - if we have the same name resolve
to different things, we'll just keep several dentries and ->d_compare()
will reject the wrong ones.
* have ->lookup() and ->readdir() scan the table of our inode first, then
walk all ctl_table_header and scan ->attached_by for those that are
attached to our directory.
* implement ->getattr().
* get rid of insane amounts of tree-walking
* get rid of the need to know dentry in ->permission() and of the contortions
induced by that.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
In a sense, that's the heart of the series. It's based on the following
property of the trees we are actually asked to add: they can be split into
stem that is already covered by registered trees and crown that is entirely
new. IOW, if a/b and a/c/d are introduced by our tree, then a/c is also
introduced by it.
That allows to associate tree and table entry with each node in the union;
while directory nodes might be covered by many trees, only one will cover
the node by its crown. And that will allow much saner logics for /proc/sys
in the next patches. This patch introduces the data structures needed to
keep track of that.
When adding a sysctl table, we find a "parent" one. Which is to say,
find the deepest node on its stem that already is present in one of the
tables from our table set or its ancestor sets. That table will be our
parent and that node in it - attachment point. Add our table to list
anchored in parent, have it refer the parent and contents of attachment
point. Also remember where its crown lives.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Refcount the sucker; instead of freeing it by the end of unregistration
just drop the refcount and free only when it hits zero. Make sure that
we _always_ make ->unregistering non-NULL in start_unregistering().
That allows anybody to get a reference to such puppy, preventing its
freeing and reuse. It does *not* block unregistration. Anybody who
holds such a reference can
* try to grab a "use" reference (ctl_head_grab()); that will
succeeds if and only if it hadn't entered unregistration yet. If it
succeeds, we can use it in all normal ways until we release the "use"
reference (with ctl_head_finish()). Note that this relies on having
->unregistering become non-NULL in all cases when one starts to unregister
the sucker.
* keep pointers to ctl_table entries; they *can* be freed if
the entire thing is unregistered. However, if ctl_head_grab() succeeds,
we know that unregistration had not happened (and will not happen until
ctl_head_finish()) and such pointers can be used safely.
IOW, now we can have inodes under /proc/sys keep references to ctl_table
entries, protecting them with references to ctl_table_header and
grabbing the latter for the duration of operations that require access
to ctl_table. That won't cause deadlocks, since unregistration will not
be stopped by mere keeping a reference to ctl_table_header.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
New object: set of sysctls [currently - root and per-net-ns].
Contains: pointer to parent set, list of tables and "should I see this set?"
method (->is_seen(set)).
Current lists of tables are subsumed by that; net-ns contains such a beast.
->lookup() for ctl_table_root returns pointer to ctl_table_set instead of
that to ->list of that ctl_table_set.
[folded compile fixes by rdd for configs without sysctl]
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
As suggested by Patrick McHardy, introduce a __krealloc() that doesn't
free the original buffer to fix a double-free and use-after-free bug
introduced by me in netfilter that uses RCU.
Reported-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Tested-by: Dieter Ries <clip2@gmx.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
