- 26 Jul, 2008 40 commits
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Nick Piggin authored
If we can be sure that elevating the page_count on a pagecache page will pin it, we can speculatively run this operation, and subsequently check to see if we hit the right page rather than relying on holding a lock or otherwise pinning a reference to the page. This can be done if get_page/put_page behaves consistently throughout the whole tree (ie. if we "get" the page after it has been used for something else, we must be able to free it with a put_page). Actually, there is a period where the count behaves differently: when the page is free or if it is a constituent page of a compound page. We need an atomic_inc_not_zero operation to ensure we don't try to grab the page in either case. This patch introduces the core locking protocol to the pagecache (ie. adds page_cache_get_speculative, and tweaks some update-side code to make it work). Thanks to Hugh for pointing out an improvement to the algorithm setting page_count to zero when we have control of all references, in order to hold off speculative getters. [kamezawa.hiroyu@jp.fujitsu.com: fix migration_entry_wait()] [hugh@veritas.com: fix add_to_page_cache] [akpm@linux-foundation.org: repair a comment] Signed-off-by:
Nick Piggin <npiggin@suse.de> Cc: Jeff Garzik <jeff@garzik.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Hugh Dickins <hugh@veritas.com> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Reviewed-by:
Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by:
Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by:
KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by:
KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by:
Hugh Dickins <hugh@veritas.com> Acked-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Nick Piggin authored
Introduce gang_lookup_slot() and gang_lookup_slot_tag() functions, which are used by lockless pagecache. Signed-off-by:
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Nick Piggin authored
radix_tree_next_hole() is implemented as a series of radix_tree_lookup()s. So it can be called locklessly, under rcu_read_lock(). Signed-off-by:
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Nick Piggin authored
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Nick Piggin authored
Use get_user_pages_fast in splice. This reverts some mmap_sem batching there, however the biggest problem with mmap_sem tends to be hold times blocking out other threads rather than cacheline bouncing. Further: on architectures that implement get_user_pages_fast without locks, mmap_sem can be avoided completely anyway. Signed-off-by:
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Nick Piggin authored
Use get_user_pages_fast in the common/generic block and fs direct IO paths. Signed-off-by:
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Nick Piggin authored
Implement get_user_pages_fast without locking in the fastpath on x86. Do an optimistic lockless pagetable walk, without taking mmap_sem or any page table locks or even mmap_sem. Page table existence is guaranteed by turning interrupts off (combined with the fact that we're always looking up the current mm, means we can do the lockless page table walk within the constraints of the TLB shootdown design). Basically we can do this lockless pagetable walk in a similar manner to the way the CPU's pagetable walker does not have to take any locks to find present ptes. This patch (combined with the subsequent ones to convert direct IO to use it) was found to give about 10% performance improvement on a 2 socket 8 core Intel Xeon system running an OLTP workload on DB2 v9.5 "To test the effects of the patch, an OLTP workload was run on an IBM x3850 M2 server with 2 processors (quad-core Intel Xeon processors at 2.93 GHz) using IBM DB2 v9.5 running Linux 2.6.24rc7 kernel. Comparing runs with and without the patch resulted in an overall performance benefit of ~9.8%. Correspondingly, oprofiles showed that samples from __up_read and __down_read routines that is seen during thread contention for system resources was reduced from 2.8% down to .05%. Monitoring the /proc/vmstat output from the patched run showed that the counter for fast_gup contained a very high number while the fast_gup_slow value was zero." (fast_gup is the old name for get_user_pages_fast, fast_gup_slow is a counter we had for the number of times the slowpath was invoked). The main reason for the improvement is that DB2 has multiple threads each issuing direct-IO. Direct-IO uses get_user_pages, and thus the threads contend the mmap_sem cacheline, and can also contend on page table locks. I would anticipate larger performance gains on larger systems, however I think DB2 uses an adaptive mix of threads and processes, so it could be that thread contention remains pretty constant as machine size increases. In which case, we stuck with "only" a 10% gain. The downside of using get_user_pages_fast is that if there is not a pte with the correct permissions for the access, we end up falling back to get_user_pages and so the get_user_pages_fast is a bit of extra work. However this should not be the common case in most performance critical code. [akpm@linux-foundation.org: coding-style fixes] [akpm@linux-foundation.org: build fix] [akpm@linux-foundation.org: Kconfig fix] [akpm@linux-foundation.org: Makefile fix/cleanup] [akpm@linux-foundation.org: warning fix] Signed-off-by:
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Nick Piggin authored
Introduce a new get_user_pages_fast mm API, which is basically a get_user_pages with a less general API (but still tends to be suited to the common case): - task and mm are always current and current->mm - force is always 0 - pages is always non-NULL - don't pass back vmas This restricted API can be implemented in a much more scalable way on many architectures when the ptes are present, by walking the page tables locklessly (no mmap_sem or page table locks). When the ptes are not populated, get_user_pages_fast() could be slower. This is implemented locklessly on x86, and used in some key direct IO call sites, in later patches, which provides nearly 10% performance improvement on a threaded database workload. Lots of other code could use this too, depending on use cases (eg. grep drivers/). And it might inspire some new and clever ways to use it. [akpm@linux-foundation.org: build fix] [akpm@linux-foundation.org: coding-style fixes] Signed-off-by:
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Nick Piggin authored
Implement the pte_special bit for x86. This is required to support lockless get_user_pages, because we need to know whether or not we can refcount a particular page given only its pte (and no vma). [hugh@veritas.com: fix a BUG] Signed-off-by:
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Harvey Harrison authored
Signed-off-by:
Harvey Harrison <harvey.harrison@gmail.com> Acked-by:
David Howells <dhowells@redhat.com> Signed-off-by:
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Harvey Harrison authored
Signed-off-by:
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Harvey Harrison authored
Signed-off-by:
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Bob Copeland authored
Add the MAINTAINERS entry for OMFS. Signed-off-by:
Bob Copeland <me@bobcopeland.com> Signed-off-by:
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Bob Copeland authored
Adds OMFS to the fs Kconfig and Makefile Signed-off-by:
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Bob Copeland authored
Add block allocation and block bitmap management routines for OMFS. Signed-off-by:
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Bob Copeland authored
Add functions for reading and manipulating the storage of file data in the extent-based OMFS. Signed-off-by:
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Bob Copeland authored
Add lookup and directory management routines for OMFS. The filesystem uses hashing based on the filename and stores collisions, unordered, in siblings of files' inode structures. To support telldir, the current position in the hash table is encoded in fpos. Signed-off-by:
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Bob Copeland authored
Add basic superblock and inode handling routines for OMFS Signed-off-by:
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Bob Copeland authored
Add header files containing OMFS on-disk and memory structures. Signed-off-by:
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Bob Copeland authored
These patches add the Optimized MPEG Filesystem, a proprietary filesystem used by the embedded devices Rio Karma and ReplayTV, which are no longer manufactured. This filesystem module enables people to access files on these devices. This patch: OMFS is a proprietary filesystem created for the ReplayTV and also used by the Rio Karma. It uses hash tables with unordered, unbounded lists in each bucket for directories, extents for data blocks, 64-bit addressing for blocks, with up to 8K blocks (only 2K of a given block is ever used for metadata, so the FS still works with 4K pages). Document the filesystem usage and structures. Signed-off-by:
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Huang Weiyi authored
Removed duplicated include <linux/uio.h> in include/linux/aio.h Signed-off-by:
Huang Weiyi <weiyi.huang@gmail.com> Signed-off-by:
Benjamin LaHaise <bcrl@kvack.org> Signed-off-by:
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Eduard - Gabriel Munteanu authored
Allows one to create and use a channel with no associated files. Files can be initialized later. This is useful in scenarios such as logging in early code, before VFS is up. Therefore, such channels can be created and used as soon as kmem_cache_init() completed. This is needed by kmemtrace to do tracing in early kernel code. [kosaki.motohiro@jp.fujitsu.com: build fix] Signed-off-by:
Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro> Cc: Tom Zanussi <tzanussi@gmail.com> Signed-off-by:
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Eduard - Gabriel Munteanu authored
A previous patch added the early_initcall(), to allow a cleaner hooking of pre-SMP initcalls. Now we remove the older interface, converting all existing users to the new one. [akpm@linux-foundation.org: cleanups] [akpm@linux-foundation.org: build fix] [kosaki.motohiro@jp.fujitsu.com: warning fix] [kosaki.motohiro@jp.fujitsu.com: warning fix] Signed-off-by:
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Eduard - Gabriel Munteanu authored
Added early initcall (pre-SMP) support, using an identical interface to that of regular initcalls. Functions called from do_pre_smp_initcalls() could be converted to use this cleaner interface. This is required by CPU hotplug, because early users have to register notifiers before going SMP. One such CPU hotplug user is the relay interface with buffer-only channels, which needs to register such a notifier, to be usable in early code. This in turn is used by kmemtrace. Signed-off-by:
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Huang Ying authored
This patch implements devices state save/restore before after kexec. This patch together with features in kexec_jump patch can be used for following: - A simple hibernation implementation without ACPI support. You can kexec a hibernating kernel, save the memory image of original system and shutdown the system. When resuming, you restore the memory image of original system via ordinary kexec load then jump back. - Kernel/system debug through making system snapshot. You can make system snapshot, jump back, do some thing and make another system snapshot. - Cooperative multi-kernel/system. With kexec jump, you can switch between several kernels/systems quickly without boot process except the first time. This appears like swap a whole kernel/system out/in. - A general method to call program in physical mode (paging turning off). This can be used to invoke BIOS code under Linux. The following user-space tools can be used with kexec jump: - kexec-tools needs to be patched to support kexec jump. The patches and the precompiled kexec can be download from the following URL: source: http://khibernation.sourceforge.net/download/release_v10/kexec-tools/kexec-tools-src_git_kh10.tar.bz2 patches: http://khibernation.sourceforge.net/download/release_v10/kexec-tools/kexec-tools-patches_git_kh10.tar.bz2 binary: http://khibernation.sourceforge.net/download/release_v10/kexec-tools/kexec_git_kh10 - makedumpfile with patches are used as memory image saving tool, it can exclude free pages from original kernel memory image file. The patches and the precompiled makedumpfile can be download from the following URL: source: http://khibernation.sourceforge.net/download/release_v10/makedumpfile/makedumpfile-src_cvs_kh10.tar.bz2 patches: http://khibernation.sourceforge.net/download/release_v10/makedumpfile/makedumpfile-patches_cvs_kh10.tar.bz2 binary: http://khibernation.sourceforge.net/download/release_v10/makedumpfile/makedumpfile_cvs_kh10 - An initramfs image can be used as the root file system of kexeced kernel. An initramfs image built with "BuildRoot" can be downloaded from the following URL: initramfs image: http://khibernation.sourceforge.net/download/release_v10/initramfs/rootfs_cvs_kh10.gz All user space tools above are included in the initramfs image. Usage example of simple hibernation: 1. Compile and install patched kernel with following options selected: CONFIG_X86_32=y CONFIG_RELOCATABLE=y CONFIG_KEXEC=y CONFIG_CRASH_DUMP=y CONFIG_PM=y CONFIG_HIBERNATION=y CONFIG_KEXEC_JUMP=y 2. Build an initramfs image contains kexec-tool and makedumpfile, or download the pre-built initramfs image, called rootfs.gz in following text. 3. Prepare a partition to save memory image of original kernel, called hibernating partition in following text. 4. Boot kernel compiled in step 1 (kernel A). 5. In the kernel A, load kernel compiled in step 1 (kernel B) with /sbin/kexec. The shell command line can be as follow: /sbin/kexec --load-preserve-context /boot/bzImage --mem-min=0x100000 --mem-max=0xffffff --initrd=rootfs.gz 6. Boot the kernel B with following shell command line: /sbin/kexec -e 7. The kernel B will boot as normal kexec. In kernel B the memory image of kernel A can be saved into hibernating partition as follow: jump_back_entry=`cat /proc/cmdline | tr ' ' '\n' | grep kexec_jump_back_entry | cut -d '='` echo $jump_back_entry > kexec_jump_back_entry cp /proc/vmcore dump.elf Then you can shutdown the machine as normal. 8. Boot kernel compiled in step 1 (kernel C). Use the rootfs.gz as root file system. 9. In kernel C, load the memory image of kernel A as follow: /sbin/kexec -l --args-none --entry=`cat kexec_jump_back_entry` dump.elf 10. Jump back to the kernel A as follow: /sbin/kexec -e Then, kernel A is resumed. Implementation point: To support jumping between two kernels, before jumping to (executing) the new kernel and jumping back to the original kernel, the devices are put into quiescent state, and the state of devices and CPU is saved. After jumping back from kexeced kernel and jumping to the new kernel, the state of devices and CPU are restored accordingly. The devices/CPU state save/restore code of software suspend is called to implement corresponding function. Known issues: - Because the segment number supported by sys_kexec_load is limited, hibernation image with many segments may not be load. This is planned to be eliminated by adding a new flag to sys_kexec_load to make a image can be loaded with multiple sys_kexec_load invoking. Now, only the i386 architecture is supported. Signed-off-by:Huang Ying <ying.huang@intel.com> Acked-by:
Vivek Goyal <vgoyal@redhat.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Nigel Cunningham <nigel@nigel.suspend2.net> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by:
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Huang Ying authored
This patch provides an enhancement to kexec/kdump. It implements the following features: - Backup/restore memory used by the original kernel before/after kexec. - Save/restore CPU state before/after kexec. The features of this patch can be used as a general method to call program in physical mode (paging turning off). This can be used to call BIOS code under Linux. kexec-tools needs to be patched to support kexec jump. The patches and the precompiled kexec can be download from the following URL: source: http://khibernation.sourceforge.net/download/release_v10/kexec-tools/kexec-tools-src_git_kh10.tar.bz2 patches: http://khibernation.sourceforge.net/download/release_v10/kexec-tools/kexec-tools-patches_git_kh10.tar.bz2 binary: http://khibernation.sourceforge.net/download/release_v10/kexec-tools/kexec_git_kh10 Usage example of calling some physical mode code and return: 1. Compile and install patched kernel with following options selected: CONFIG_X86_32=y CONFIG_KEXEC=y CONFIG_PM=y CONFIG_KEXEC_JUMP=y 2. Build patched kexec-tool or download the pre-built one. 3. Build some physical mode executable named such as "phy_mode" 4. Boot kernel compiled in step 1. 5. Load physical mode executable with /sbin/kexec. The shell command line can be as follow: /sbin/kexec --load-preserve-context --args-none phy_mode 6. Call physical mode executable with following shell command line: /sbin/kexec -e Implementation point: To support jumping without reserving memory. One shadow backup page (source page) is allocated for each page used by kexeced code image (destination page). When do kexec_load, the image of kexeced code is loaded into source pages, and before executing, the destination pages and the source pages are swapped, so the contents of destination pages are backupped. Before jumping to the kexeced code image and after jumping back to the original kernel, the destination pages and the source pages are swapped too. C ABI (calling convention) is used as communication protocol between kernel and called code. A flag named KEXEC_PRESERVE_CONTEXT for sys_kexec_load is added to indicate that the loaded kernel image is used for jumping back. Now, only the i386 architecture is supported. Signed-off-by: -
WANG Cong authored
Since kimage_terminate() always returns 0, make it void. Signed-off-by:
WANG Cong <wangcong@zeuux.org> Signed-off-by:
"Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by:
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Alex Dubov authored
Instead of using a separate thread to pump requests from block layer queue to memstick, do so inline, utilizing the callback design of the memstick. [akpm@linux-foundation.org: fix warnings] Signed-off-by:
Alex Dubov <oakad@yahoo.com> Signed-off-by:
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Alex Dubov authored
In some cases it may be desirable to ensure that associated driver is not going to access the media in some period of time. "start" and "stop" methods are provided therefore to allow it. Signed-off-by:
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Alex Dubov authored
Some controllers (Jmicron, for instance) can report temporal failure condition during power-on. It is desirable to account for this using a return value of "set_param" device method. The return value can also be handy to distinguish between supported and unsupported device parameters in run time. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by:
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Michael Halcrow authored
Use the correct data types for the size parameters in tpm_write() and tpm_read(). Note that rw_verify_area() makes sure that this bug cannot be exploited to produce a buffer overrun. Signed-off-by:
Michael Halcrow <mhalcrow@us.ibm.com> Cc: Marcel Selhorst <tpm@selhorst.net> Signed-off-by:
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Marcin Obara authored
This patch increases size of driver internal response buffers. Some TPM responses defined in TCG TPM Specification Version 1.2 Revision 103 have increased size and do not fit previously defined buffers. Some TPM responses do not have fixed size, so bigger response buffers have to be allocated. 200B buffers should be enough. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by:
Marcin Obara <marcin_obara@users.sourceforge.net> Cc: Marcel Selhorst <tpm@selhorst.net> Cc: Kylene Jo Hall <kjhall@us.ibm.com> Signed-off-by:
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Adrian Bunk authored
This patch makes two needlessly global structs static. Signed-off-by:
Adrian Bunk <bunk@kernel.org> Acked-by:
Marcel Selhorst <tpm@selhorst.net> Signed-off-by:
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LE DISEZ Erwan authored
Signed-off-by:
Rajiv Andrade <srajiv@linux.vnet.ibm.com> Cc: Marcel Selhorst <tpm@selhorst.net> Signed-off-by:
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Bernhard Walle authored
Use the 2nd BAR for the oxsemi_840 chip as BAR for base_hi. Tested with: Parallel controller [0701]: Oxford Semiconductor Ltd VScom 011H-EP1 1 port parallel adaptor [1415:8403] (prog-if 03 [IEEE1284]) This patch is needed to make 'TRISTATE' work with that adaptor. Signed-off-by:Bernhard Walle <bwalle@suse.de> Signed-off-by:
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Andre Haupt authored
Signed-off-by:
Andre Haupt <andre@bitwigglers.org> Signed-off-by:
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Adrian Bunk authored
This patch adds proper externs for parport_default_timeslice and parport_default_spintime in include/linux/parport.h Signed-off-by:
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Dmitri Vorobiev authored
Replace the BKL-based locking scheme used in the bfs driver by a private filesystem-wide mutex. Signed-off-by:
Dmitri Vorobiev <dmitri.vorobiev@movial.fi> Cc: Tigran Aivazian <tigran_aivazian@symantec.com> Signed-off-by:
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Dmitri Vorobiev authored
This patch makes the following cleanups: o removing an unused variable from bfs_fill_super(); o removing unneeded blank spaces from pointer definitions. Signed-off-by:
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Matthias Kaehlcke authored
The semaphore s_bmlock is used as a mutex. Convert it to the mutex API. Signed-off-by:
Matthias Kaehlcke <matthias@kaehlcke.net> Cc: Roman Zippel <zippel@linux-m68k.org> Signed-off-by:
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