Eliminate the open_mutex after complaints from Blaisorblade. It turns out
that the tty count provides the information needed to tell whether we are the
first opener or last closer.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Remove the last vestiges of devfs from console registration. Change the name
of the function, plus remove a couple of unused fields from the line_driver
structure.
struct lines is no longer needed, all traces of it are gone.
The only way that I can see to mark a structure as being almost-const is to
individually const the fields. This is the case for the line_driver
structure, which has only one modifiable field - a list_head in a
sub-structure.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Whitespace fixes and emacs comment removal.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The chan_opts structure is mostly const, and needs no locking. Comment the
lack of locking on the one field that can change.
Make all the other fields const. It turned out that console_open_chan didn't
use its chan_opts argument, so that is deleted from the function and its
callers.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Comment the lack of locking.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A couple of list_head declarations can be improved through the use of
LIST_HEAD().
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add some missing locking to walks of the transports and opened lists.
Delete some dead code.
Comment the lack of some locking.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Kill a compilation warning.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Whitespace and style fixes.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Make a couple of variables static.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Locking fixes. Locking was totally lacking for the mconsole_devices, which
got a spin lock, and the unplugged pages data, which got a mutex.
The locking of the mconsole console output code was confused. Now, the
console_lock (renamed to client_lock) protects the clients list.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Whitespace and style fixes.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Comment the lack of locking and make a couple of variables static.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Whitespace and style fixes.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Replace BKL use with a spinlock.
Also fix the control so that open doesn't return holding a lock.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Some whitespace and coding style cleanups in the network driver code.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Acked-by: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The registration of host network transports needed some locking. The
transport list itself is locked, but calls to the registration routines are
not. This is compensated for by checking that a transport structure is not
yet on any list.
I also took the opportunity to const all fields in the transport structure
except the list, which obviously can be modified.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix (i.e. add some) the locking around the irqs_to_free list.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Some comment and whitespace cleanups in the console and mconsole code.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
I noticed that errors happening while hotplugging devices from the host were
never returned back to the mconsole client. In some cases, success was
returned instead of even an information-free error.
This patch cleans that up by having the low-level configuration code pass back
an error string along with an error code. At the top level, which knows
whether it is early boot time or responding to an mconsole request, the string
is printk'd or returned to the mconsole client.
There are also whitespace and trivial code cleanups in the surrounding code.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Clean up the console driver locking. There are various problems here,
including sleeping under a spinlock and spinlock recursion, some of which are
fixed here. This patch deals with the locking involved with opens and closes.
The problem is that an mconsole request to change a console's configuration
can race with an open. Changing a configuration should only be done when a
console isn't opened. Also, an open must be looking at a stable
configuration. In addition, a get configuration request must observe the same
locking since it must also see a stable configuration. With the old locking,
it was possible for this to hang indefinitely in some cases because open would
block for a long time waiting for a connection from the host while holding the
lock needed by the mconsole request.
As explained in the long comment, this is fixed by adding a spinlock for the
use count and configuration and a mutex for the actual open and close.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
TLB handling for CRIS contains local_irq_disable() after local_save_flags().
Turn this into local_irq_save().
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Cc: Mikael Starvik <starvik@axis.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use ARRAY_SIZE macro already defined in linux/kernel.h
Signed-off-by: Ahmed S. Darwish <darwish.07@gmail.com>
Cc: Mikael Starvik <starvik@axis.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Various headers for CRIS architecture contain local_irq_disable() after
local_save_flags(). Turn it into local_irq_save().
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Cc: Mikael Starvik <starvik@axis.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We don't actually use anything from asm-m68k/page.h in asm-m68k/user.h, so
don't bother including it
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use ARRAY_SIZE macro already defined in linux/kernel.h
Signed-off-by: Ahmed S. Darwish <darwish.07@gmail.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use ARRAY_SIZE macro already defined in linux/kernel.h
Signed-off-by: Ahmed S. Darwish <darwish.07@gmail.com>
Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
kernel/time/clocksource.c needs struct task_struct on m68k.
Because it uses spin_unlock_irq(), which, on m68k, uses hardirq_count(), which
uses preempt_count(), which needs to dereference struct task_struct, we
have to include sched.h. Because it would cause a loop inclusion, we
cannot include sched.h in any other of asm-m68k/system.h,
linux/thread_info.h, linux/hardirq.h, which leaves this ugly include in
a C file as the only simple solution.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Recent as(1) doesn't think that . terminates a macro name, so getuser.l is
_not_ treated as invoking getuser with .l as the first argument.
arch/m68k/math-emu relies on old behaviour, so it gets a lot of undefined
macros with more or less current binutils.
Note that this behaviour remains in all recent versions and is unrelated to
another binutils problems we used to have for a while (having (%a0)+ parsed
as two arguments). This one is there to stay; it's an intentional and
documented change.
.irp <identifier> <words>
[text]
.endr
expands to a copy of text per each word, with \<identifier> replaced with
corresponding word. Again, what happens depends on whether gas_ident.x
is treated as one or as two tokens; in the former case we'll get old_gas
incremented once, in the latter - twice. The rest is obvious.
Unlike .macro argument list _anything_ is explicitly allowed after
.irp <identifier>; here we are on very safe ground. And yes, it does
work with all gas variants I've got here (including vanilla 2.15, 2.16,
2.16.1 and 2.17, plus debian and FC binutils).
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cosmetic updates and trivial fixes of m32r arch-dependent files.
- Remove RCS ID strings and trailing white lines
- Other misc. cosmetic updates
Signed-off-by: Hirokazu Takata <takata@linux-m32r.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch fixes the kernel entry point address of vmlinux.
The m32r kernel entry address is 0x08002000 (physical).
But, so far, the ENTRY point written in vmlinux.lds.S was not point
the correct kernel entry address.
(before fix)
$ objdump -x vmlinux
vmlinux: file format elf32-m32r-linux
vmlinux
architecture: m32r2, flags 0x00000112:
EXEC_P, HAS_SYMS, D_PAGED
start address 0x88002090 /* NG */
:
Sections:
Idx Name Size VMA LMA File off Algn
0 .empty_zero_page 00001000 88001000 88001000 00001000 2**12
CONTENTS, ALLOC, LOAD, DATA
1 .boot 0000008c 88002000 88002000 00002000 2**2
CONTENTS, ALLOC, LOAD, READONLY, CODE
2 .text 001ab694 88002090 88002090 00002090 2**4
CONTENTS, ALLOC, LOAD, READONLY, CODE
:
(after fix)
$ objdump -x vmlinux
vmlinux: file format elf32-m32r-linux
vmlinux
architecture: m32r2, flags 0x00000112:
EXEC_P, HAS_SYMS, D_PAGED
start address 0x08002000 /* OK */
:
This fix also remedies the following GDB error message (of gdb-6.4 or after)
at the first operation of kernel debugging:
"Previous frame identical to this frame (corrupt stack?)".
Signed-off-by: Hirokazu Takata <takata@linux-m32r.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix do_page_fault and update_mmu_cache.
* Fix do_page_fault (vmalloc_fault:) to pass error_code correctly
to update_mmu_cache by using a thread-fault code for all m32r chips.
* Fix update_mmu_cache for OPSP chip
- #ifdef CONFIG_CHIP_OPSP portion is a workaround of OPSP;
Add a notfound-case operation to update_mmu_cache for OPSP
like other m32r chip.
- Fix pte_data that was not initialized if no entry found.
Signed-off-by: Kazuhiro Inaoka <inaoka@linux-m32r.org>
Signed-off-by: Hirokazu Takata <takata@linux-m32r.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Additional fixes for processors without ISA_DSP_LEVEL2. sigcontext_t does not
have dummy_acc1h, dummy_acc1l members any longer.
Signed-off-by: Hirokazu Takata <takata@linux-m32r.org>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Make the userland interface of swsusp call pm_ops->finish() after
enable_nonboot_cpus() and before resume_device(), as indicated by the recent
discussion on Linux-PM (cf.
http://lists.osdl.org/pipermail/linux-pm/2006-November/004164.html).
This patch changes the SNAPSHOT_PMOPS ioctl so that its first function,
PMOPS_PREPARE, only sets a switch turning the platform suspend mode on, and
its last function, PMOPS_FINISH, only checks if the platform mode is enabled.
This should allow the older userland tools to work with new kernels without
any modifications.
The changes here only affect the userland interface of swsusp.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Cc: Greg KH <greg@kroah.com>
Cc: Nigel Cunningham <nigel@suspend2.net>
Cc: Patrick Mochel <mochel@digitalimplant.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The compiler will do that. And if it doesn't, we don't want to either ;)
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Greg KH <greg@kroah.com>
Cc: Nigel Cunningham <nigel@suspend2.net>
Cc: Patrick Mochel <mochel@digitalimplant.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Change the ordering of code in kernel/power/user.c so that device_suspend() is
called before disable_nonboot_cpus() and device_resume() is called after
enable_nonboot_cpus(). This is needed to make the userland suspend call
pm_ops->finish() after enable_nonboot_cpus() and before device_resume(), as
indicated by the recent discussion on Linux-PM (cf.
http://lists.osdl.org/pipermail/linux-pm/2006-November/004164.html).
The changes here only affect the userland interface of swsusp.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Cc: Greg KH <greg@kroah.com>
Cc: Nigel Cunningham <nigel@suspend2.net>
Cc: Patrick Mochel <mochel@digitalimplant.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Change the ordering of code in kernel/power/disk.c so that device_suspend() is
called before disable_nonboot_cpus() and platform_finish() is called after
enable_nonboot_cpus() and before device_resume(), as indicated by the recent
discussion on Linux-PM (cf.
http://lists.osdl.org/pipermail/linux-pm/2006-November/004164.html).
The changes here only affect the built-in swsusp.
[alexey.y.starikovskiy@linux.intel.com: fix LED blinking during image load]
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Cc: Greg KH <greg@kroah.com>
Cc: Nigel Cunningham <nigel@suspend2.net>
Cc: Patrick Mochel <mochel@digitalimplant.org>
Cc: Alexey Starikovskiy <alexey.y.starikovskiy@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
As indicated in a recent thread on Linux-PM, it's necessary to call
pm_ops->finish() before devce_resume(), but enable_nonboot_cpus() has to be
called before pm_ops->finish() (cf.
http://lists.osdl.org/pipermail/linux-pm/2006-November/004164.html). For
consistency, it seems reasonable to call disable_nonboot_cpus() after
device_suspend().
This way the suspend code will remain symmetrical with respect to the resume
code and it may allow us to speed up things in the future by suspending and
resuming devices and/or saving the suspend image in many threads.
The following series of patches reorders the suspend and resume code so that
nonboot CPUs are disabled after devices have been suspended and enabled before
the devices are resumed. It also causes pm_ops->finish() to be called after
enable_nonboot_cpus() wherever necessary.
This patch:
Change the ordering of code in kernel/power/main.c so that device_suspend()
is called before disable_nonboot_cpus() and pm_ops->finish() is called after
enable_nonboot_cpus() and before device_resume(), as indicated by recent
discussion on Linux-PM
(cf. http://lists.osdl.org/pipermail/linux-pm/2006-November/004164.html).
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Cc: Greg KH <greg@kroah.com>
Cc: Nigel Cunningham <nigel@suspend2.net>
Cc: Patrick Mochel <mochel@digitalimplant.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use ARRAY_SIZE macro already defined in linux/kernel.h
Signed-off-by: Ahmed S. Darwish <darwish.07@gmail.com>
Acked-by: Ian Molton <spyro@f2s.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Module loading on Alpha was failing with error "Could not allocate 8 bytes
percpu data".
Looking at dmesg we have the below error "No per-cpu room for modules."
Increase the PERCPU_ENOUGH_ROOM in a similar way as x86_64
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@gmail.com>
Cc: <Jay.Estabrook@hp.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Reading /proc/sys/kernel/cap-bound requires CAP_SYS_MODULE. (see
proc_dointvec_bset in kernel/sysctl.c)
sysctl appears to drive all over proc reading everything it can get it's
hands on and is complaining when it is being denied access to read
cap-bound. Clearly writing to cap-bound should be a sensitive operation
but requiring CAP_SYS_MODULE to read cap-bound seems a bit to strong. I
believe the information could with reasonable certainty be obtained by
looking at a bunch of the output of /proc/pid/status which has very low
security protection, so at best we are just getting a little obfuscation of
information.
Currently SELinux policy has to 'dontaudit' capability checks for
CAP_SYS_MODULE for things like sysctl which just want to read cap-bound.
In doing so we also as a byproduct have to hide warnings of potential
exploits such as if at some time that sysctl actually tried to load a
module. I wondered if anyone would have a problem opening cap-bound up to
read from anyone?
Acked-by: Chris Wright <chrisw@sous-sol.org>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: James Morris <jmorris@namei.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When kernel unmaps an address range, it needs to transfer PTE state into
page struct. Currently, kernel transfer access bit via
mark_page_accessed(). The call to mark_page_accessed in the unmap path
doesn't look logically correct.
At unmap time, calling mark_page_accessed will causes page LRU state to be
bumped up one step closer to more recently used state. It is causing quite
a bit headache in a scenario when a process creates a shmem segment, touch
a whole bunch of pages, then unmaps it. The unmapping takes a long time
because mark_page_accessed() will start moving pages from inactive to
active list.
I'm not too much concerned with moving the page from one list to another in
LRU. Sooner or later it might be moved because of multiple mappings from
various processes. But it just doesn't look logical that when user asks a
range to be unmapped, it's his intention that the process is no longer
interested in these pages. Moving those pages to active list (or bumping
up a state towards more active) seems to be an over reaction. It also
prolongs unmapping latency which is the core issue I'm trying to solve.
As suggested by Peter, we should still preserve the info on pte young
pages, but not more.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Ken Chen <kenchen@google.com>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
As pointed out by Hugh, ramfs would also benefit from using the new
set_page_dirty aop method for memory backed file systems.
Signed-off-by: Ken Chen <kenchen@google.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
shmem backed file does not have page writeback, nor it participates in
backing device's dirty or writeback accounting. So using generic
__set_page_dirty_nobuffers() for its .set_page_dirty aops method is a bit
overkill. It unnecessarily prolongs shm unmap latency.
For example, on a densely populated large shm segment (sevearl GBs), the
unmapping operation becomes painfully long. Because at unmap, kernel
transfers dirty bit in PTE into page struct and to the radix tree tag. The
operation of tagging the radix tree is particularly expensive because it
has to traverse the tree from the root to the leaf node on every dirty
page. What's bothering is that radix tree tag is used for page write back.
However, shmem is memory backed and there is no page write back for such
file system. And in the end, we spend all that time tagging radix tree and
none of that fancy tagging will be used. So let's simplify it by introduce
a new aops __set_page_dirty_no_writeback and this will speed up shm unmap.
Signed-off-by: Ken Chen <kenchen@google.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently if we have a non-zero ZONES_SHIFT we assume we are able to rely
on that as the bottom edge of the ZONEID, if not then we use the
NODES_PGOFF as the right end of either NODES _or_ SECTION. This latter is
more luck than judgement and would be incorrect if we reordered the
SECTION,NODE,ZONE options in the fields space.
Really what we want is the lower of the right hand end of the two fields we
are using (either NODE,ZONE or SECTION,ZONE). Codify that explicitly. As
always allow for there being no bits in either of the fields, such as might
be valid in a non-numa machine with only a zone NORMAL.
I have checked that the compiler is still able to constant fold all of this
away correctly.
Signed-off-by: Andy Whitcroft <apw@shadowen.org>
Acked-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
As Andi pointed out: CONFIG_GENERIC_ISA_DMA only disables the ISA DMA
channel management. Other functionality may still expect GFP_DMA to
provide memory below 16M. So we need to make sure that CONFIG_ZONE_DMA is
set independent of CONFIG_GENERIC_ISA_DMA. Undo the modifications to
mm/Kconfig where we made ZONE_DMA dependent on GENERIC_ISA_DMA and set
theses explicitly in each arches Kconfig.
Reviews must occur for each arch in order to determine if ZONE_DMA can be
switched off. It can only be switched off if we know that all devices
supported by a platform are capable of performing DMA transfers to all of
memory (Some arches already support this: uml, avr32, sh sh64, parisc and
IA64/Altix).
In order to switch ZONE_DMA off conditionally, one would have to establish
a scheme by which one can assure that no drivers are enabled that are only
capable of doing I/O to a part of memory, or one needs to provide an
alternate means of performing an allocation from a specific range of memory
(like provided by alloc_pages_range()) and insure that all drivers use that
call. In that case the arches alloc_dma_coherent() may need to be modified
to call alloc_pages_range() instead of relying on GFP_DMA.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
sh / sh64: Remove ZONE_DMA remains.
Both arches do not need ZONE_DMA
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Remove ZONE_DMA remains from parisc so that kernels are build without
ZONE_DMA.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Matthew Wilcox <willy@debian.org>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
