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* SL*B: drop kmem cache argument from constructorAlexey Dobriyan2008-07-26
| | | | | | | | | | | | | | | | | | | | | | | | Kmem cache passed to constructor is only needed for constructors that are themselves multiplexeres. Nobody uses this "feature", nor does anybody uses passed kmem cache in non-trivial way, so pass only pointer to object. Non-trivial places are: arch/powerpc/mm/init_64.c arch/powerpc/mm/hugetlbpage.c This is flag day, yes. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Acked-by: Pekka Enberg <penberg@cs.helsinki.fi> Acked-by: Christoph Lameter <cl@linux-foundation.org> Cc: Jon Tollefson <kniht@linux.vnet.ibm.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Matt Mackall <mpm@selenic.com> [akpm@linux-foundation.org: fix arch/powerpc/mm/hugetlbpage.c] [akpm@linux-foundation.org: fix mm/slab.c] [akpm@linux-foundation.org: fix ubifs] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* x86: support 1GB hugepages with get_user_pages_lockless()Nick Piggin2008-07-26
| | | | | | | | | Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Andi Kleen <andi@firstfloor.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* x86: lockless get_user_pages_fast()Nick Piggin2008-07-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: Nick Piggin <npiggin@suse.de> Cc: Dave Kleikamp <shaggy@austin.ibm.com> Cc: Andy Whitcroft <apw@shadowen.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Andi Kleen <andi@firstfloor.org> Cc: Dave Kleikamp <shaggy@austin.ibm.com> Cc: Badari Pulavarty <pbadari@us.ibm.com> Cc: Zach Brown <zach.brown@oracle.com> Cc: Jens Axboe <jens.axboe@oracle.com> Reviewed-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>
* mn10300: use the common ascii hex helpersHarvey Harrison2008-07-26
| | | | | | | Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Acked-by: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* frv: use the common ascii hex helpersHarvey Harrison2008-07-26
| | | | | | | Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Acked-by: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* cris: use the common ascii hex helpersHarvey Harrison2008-07-26
| | | | | | | Signed-off-by: Harvey Harrison <harvey.harrison@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>
* kexec jump: save/restore device stateHuang Ying2008-07-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* kexec jumpHuang Ying2008-07-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: 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: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* x86 calgary: fix handling of devices that aren't behind the CalgaryAlexis Bruemmer2008-07-26
| | | | | | | | | | | | | | | | | | | The calgary code can give drivers addresses above 4GB which is very bad for hardware that is only 32bit DMA addressable. With this patch, the calgary code sets the global dma_ops to swiotlb or nommu properly, and the dma_ops of devices behind the Calgary/CalIOC2 to calgary_dma_ops. So the calgary code can handle devices safely that aren't behind the Calgary/CalIOC2. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Alexis Bruemmer <alexisb@us.ibm.com> Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Cc: Muli Ben-Yehuda <muli@il.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* dma-mapping: add the device argument to dma_mapping_error()FUJITA Tomonori2008-07-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add per-device dma_mapping_ops support for CONFIG_X86_64 as POWER architecture does: This enables us to cleanly fix the Calgary IOMMU issue that some devices are not behind the IOMMU (http://lkml.org/lkml/2008/5/8/423). I think that per-device dma_mapping_ops support would be also helpful for KVM people to support PCI passthrough but Andi thinks that this makes it difficult to support the PCI passthrough (see the above thread). So I CC'ed this to KVM camp. Comments are appreciated. A pointer to dma_mapping_ops to struct dev_archdata is added. If the pointer is non NULL, DMA operations in asm/dma-mapping.h use it. If it's NULL, the system-wide dma_ops pointer is used as before. If it's useful for KVM people, I plan to implement a mechanism to register a hook called when a new pci (or dma capable) device is created (it works with hot plugging). It enables IOMMUs to set up an appropriate dma_mapping_ops per device. The major obstacle is that dma_mapping_error doesn't take a pointer to the device unlike other DMA operations. So x86 can't have dma_mapping_ops per device. Note all the POWER IOMMUs use the same dma_mapping_error function so this is not a problem for POWER but x86 IOMMUs use different dma_mapping_error functions. The first patch adds the device argument to dma_mapping_error. The patch is trivial but large since it touches lots of drivers and dma-mapping.h in all the architecture. This patch: dma_mapping_error() doesn't take a pointer to the device unlike other DMA operations. So we can't have dma_mapping_ops per device. Note that POWER already has dma_mapping_ops per device but all the POWER IOMMUs use the same dma_mapping_error function. x86 IOMMUs use device argument. [akpm@linux-foundation.org: fix sge] [akpm@linux-foundation.org: fix svc_rdma] [akpm@linux-foundation.org: build fix] [akpm@linux-foundation.org: fix bnx2x] [akpm@linux-foundation.org: fix s2io] [akpm@linux-foundation.org: fix pasemi_mac] [akpm@linux-foundation.org: fix sdhci] [akpm@linux-foundation.org: build fix] [akpm@linux-foundation.org: fix sparc] [akpm@linux-foundation.org: fix ibmvscsi] Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Cc: Muli Ben-Yehuda <muli@il.ibm.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: Avi Kivity <avi@qumranet.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* x86_64: fix ia32 AMD syscall audit fast-pathRoland McGrath2008-07-25
| | | | | | | | | | The new code in commit 5cbf1565f29eb57a86a305b08836613508e294d7 has a bug in the version supporting the AMD 'syscall' instruction. It clobbers the user's %ecx register value (with the %ebp value). This change fixes it. Signed-off-by: Roland McGrath <roland@redhat.com>
* Merge branch 'merge' of ↵Linus Torvalds2008-07-25
|\ | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc * 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: powerpc: Fix boot problem due to AT_BASE_PLATFORM change
| * powerpc: Fix boot problem due to AT_BASE_PLATFORM changeNathan Lynch2008-07-25
| | | | | | | | | | | | | | | | | | | | | | | | Commit 9115d13453dee22473a1e8cacc90a8d64a9c4bc9 ("powerpc: Enable AT_BASE_PLATFORM aux vector") broke boot on 32-bit powerpc systems; we have to use PTRRELOC to initialize powerpc_base_platform this early in boot. Bug reported by Jon Smirl. Signed-off-by: Nathan Lynch <ntl@pobox.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* | Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6Linus Torvalds2008-07-25
|\ \ | | | | | | | | | | | | * git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6: sparc: Wire up new system calls.
| * | sparc: Wire up new system calls.David S. Miller2008-07-25
| | | | | | | | | | | | | | | | | | | | | This wires up the recently added Wire up signalfd4, eventfd2, epoll_create1, dup3, pipe2, and inotify_init1 system calls. Signed-off-by: David S. Miller <davem@davemloft.net>
* | | Merge branch 'release' of ↵Linus Torvalds2008-07-25
|\ \ \ | |_|/ |/| | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6 * 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6: [IA64] Wire up new system calls
| * | [IA64] Wire up new system callsTony Luck2008-07-25
| |/ | | | | | | | | | | | | Six new system calls: signalfd4, eventfd2, epoll_create1, dup3, pipe2 and inotify_init1. Signed-off-by: Tony Luck <tony.luck@intel.com>
* | Merge branch 'merge' of ↵Linus Torvalds2008-07-25
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc * 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (34 commits) powerpc: Wireup new syscalls Move update_mmu_cache() declaration from tlbflush.h to pgtable.h powerpc/pseries: Remove kmalloc call in handling writes to lparcfg powerpc/pseries: Update arch vector to indicate support for CMO ibmvfc: Add support for collaborative memory overcommit ibmvscsi: driver enablement for CMO ibmveth: enable driver for CMO ibmveth: Automatically enable larger rx buffer pools for larger mtu powerpc/pseries: Verify CMO memory entitlement updates with virtual I/O powerpc/pseries: vio bus support for CMO powerpc/pseries: iommu enablement for CMO powerpc/pseries: Add CMO paging statistics powerpc/pseries: Add collaborative memory manager powerpc/pseries: Utilities to set firmware page state powerpc/pseries: Enable CMO feature during platform setup powerpc/pseries: Split retrieval of processor entitlement data into a helper routine powerpc/pseries: Add memory entitlement capabilities to /proc/ppc64/lparcfg powerpc/pseries: Split processor entitlement retrieval and gathering to helper routines powerpc/pseries: Remove extraneous error reporting for hcall failures in lparcfg powerpc: Fix compile error with binutils 2.15 ... Fixed up conflict in arch/powerpc/platforms/52xx/Kconfig manually.
| * | powerpc/pseries: Remove kmalloc call in handling writes to lparcfgNathan Fontenot2008-07-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are only 4 valid name=value pairs for writes to /proc/ppc64/lparcfg. Current code allocates a buffer to copy this information in from the user. Since the longest name=value pair will easily fit into a buffer of 64 characters, simply put the buffer on the stack instead of allocating the buffer. Signed-off-by: Nathan Fotenot <nfont@austin.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * | powerpc/pseries: Update arch vector to indicate support for CMONathan Fontenot2008-07-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Update the architecture vector to indicate that Cooperative Memory Overcommitment is supported if CONFIG_PPC_SMLPAR is set. Signed-off-by: Nathan Fontenot <nfont@austin.ibm.com> Signed-off-by: Robert Jennings <rcj@linux.vnet.ibm.com> Acked-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * | powerpc/pseries: Verify CMO memory entitlement updates with virtual I/ONathan Fontenot2008-07-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | Verify memory entitlement updates can be handled by vio. Signed-off-by: Nathan Fontenot <nfont@austin.ibm.com> Signed-off-by: Robert Jennings <rcj@linux.vnet.ibm.com> Acked-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * | powerpc/pseries: vio bus support for CMORobert Jennings2008-07-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is a large patch but the normal code path is not affected. For non-pSeries platforms the code is ifdef'ed out and for non-CMO enabled pSeries systems this does not affect the normal code path. Devices that do not perform DMA operations do not need modification with this patch. The function get_desired_dma was renamed from get_io_entitlement for clarity. Overview Cooperative Memory Overcommitment (CMO) allows for a set of OS partitions to be run with less RAM than the aggregate needs of the group of partitions. The firmware will balance memory between the partitions and page in/out memory as needed. Based on the number and type of IO adpaters preset each partition is allocated an amount of memory for DMA operations and this allocation will be guaranteed to the partition; this is referred to as the partition's 'entitlement'. Partitions running in a CMO environment can only have virtual IO devices present. The VIO bus layer will manage the IO entitlement for the system. Accounting, at a system and per-device level, is tracked in the VIO bus code and exposed via sysfs. A set of dma_ops functions are added to the bus to allow for this accounting. Bus initialization At initialization, the bus will calculate the minimum needs of the system based on providing each device present with a standard minimum entitlement along with a spare allocation for the bus to handle hotplug events. If the minimum needs can not be met the system boot will be halted. Device changes The significant changes for devices while running under CMO are that the devices must specify how much dedicated IO entitlement they desire and must also handle DMA mapping errors that can occur due to constrained IO memory. The virtual IO drivers are modified to silence errors when DMA mappings fail for CMO and handle these failures gracefully. Each devices will be guaranteed a minimum entitlement that can always be mapped. Devices will specify how much entitlement they desire and the VIO bus will attempt to provide for this. Devices can change their desired entitlement level at any point in time to address particular needs (via vio_cmo_set_dev_desired()), not just at device probe time. VIO bus changes The system will have a particular entitlement level available from which it can provide memory to the devices. The bus defines two pools of memory within this entitlement, the reserved and excess pools. Each device is provided with it's own entitlement no less than a system defined minimum entitlement and no greater than what the device has specified as it's desired entitlement. The entitlement provided to devices comes from the reserve pool. The reserve pool can also contain a spare allocation as large as the system defined minimum entitlement which is used for device hotplug events. Any entitlement not needed to fulfill the needs of a reserve pool is placed in the excess pool. Each device is guaranteed that it can map up to it's entitled level; additional mapping are possible as long as there is unmapped memory in the excess pool. Bus probe As the system starts, each device is given an entitlement equal only to the system defined minimum entitlement. The reserve pool is equal to the sum of these entitlements, plus a spare allocation. The VIO bus also tracks the aggregate desired entitlement of all the devices. If the system desired entitlement is greater than the size of the reserve pool, when devices unmap IO memory it will be reserved and a balance operation will be scheduled for some time in the future. Entitlement balancing The balance function tries to fairly distribute entitlement between the devices in the system with the goal of providing each device with it's desired amount of entitlement. Devices using more than what would be ideal will have their entitled set-point adjusted; this will effectively set a goal for lower IO memory usage as future mappings can fail and deallocations will trigger a balance operation to distribute the newly unmapped memory. A fair distribution of entitlement can take several balance operations to achieve. Entitlement changes and device DLPAR events will alter the state of CMO and will trigger balance operations. Hotplug events The VIO bus allows for changes in system entitlement at run-time via 'vio_cmo_entitlement_update()'. When devices are added the hotplug device event will be preceded by a system entitlement increase and this is reversed when devices are removed. The following changes are made that the VIO bus layer for CMO: * add IO memory accounting per device structure. * add IO memory entitlement query function to driver structure. * during vio bus probe, if CMO is enabled, check that driver has memory entitlement query function defined. Fail if function not defined. * fail to register driver if io entitlement function not defined. * create set of dma_ops at vio level for CMO that will track allocations and return DMA failures once entitlement is reached. Entitlement will limited by overall system entitlement. Devices will have a reserved quantity of memory that is guaranteed, the rest can be used as available. * expose entitlement, current allocation, desired allocation, and the allocation error counter for devices to the user through sysfs * provide mechanism for changing a device's desired entitlement at run time for devices as an exported function and sysfs tunable * track any DMA failures for entitled IO memory for each vio device. * check entitlement against available system entitlement on device add * track entitlement metrics (high water mark, current usage) * provide function to reset high water mark * provide minimum and desired entitlement numbers at a bus level * provide drivers with a minimum guaranteed entitlement * balance available entitlement between devices to satisfy their needs * handle system entitlement changes and device hotplug Signed-off-by: Robert Jennings <rcj@linux.vnet.ibm.com> Acked-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * | powerpc/pseries: iommu enablement for CMORobert Jennings2008-07-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | To support Cooperative Memory Overcommitment (CMO), we need to check for failure from some of the tce hcalls. These changes for the pseries platform affect the powerpc architecture; patches for the other affected platforms are included in this patch. pSeries platform IOMMU code changes: * platform TCE functions must handle H_NOT_ENOUGH_RESOURCES errors and return an error. Architecture IOMMU code changes: * Calls to ppc_md.tce_build need to check return values and return DMA_MAPPING_ERROR for transient errors. Architecture changes: * struct machdep_calls for tce_build*_pSeriesLP functions need to change to indicate failure. * all other platforms will need updates to iommu functions to match the new calling semantics; they will return 0 on success. The other platforms default configs have been built, but no further testing was performed. Signed-off-by: Robert Jennings <rcj@linux.vnet.ibm.com> Acked-by: Olof Johansson <olof@lixom.net> Acked-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * | powerpc/pseries: Add CMO paging statisticsBrian King2008-07-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With the addition of Cooperative Memory Overcommitment (CMO) support for IBM Power Systems, two fields have been added to the VPA to report paging statistics. Add support in lparcfg to report them to userspace. Signed-off-by: Brian King <brking@linux.vnet.ibm.com> Signed-off-by: Robert Jennings <rcj@linux.vnet.ibm.com> Acked-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * | powerpc/pseries: Add collaborative memory managerBrian King2008-07-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Adds a collaborative memory manager, which acts as a simple balloon driver for System p machines that support cooperative memory overcommitment (CMO). Adds a platform configuration option for CMO called PPC_SMLPAR. Signed-off-by: Brian King <brking@linux.vnet.ibm.com> Signed-off-by: Robert Jennings <rcj@linux.vnet.ibm.com> Acked-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * | powerpc/pseries: Utilities to set firmware page stateBrian King2008-07-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Newer versions of firmware support page states, which are used by the collaborative memory manager (future patch) to "loan" pages to the hypervisor for use by other partitions. Signed-off-by: Brian King <brking@linux.vnet.ibm.com> Signed-off-by: Robert Jennings <rcj@linux.vnet.ibm.com> Acked-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * | powerpc/pseries: Enable CMO feature during platform setupRobert Jennings2008-07-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For Cooperative Memory Overcommitment (CMO), set the FW_FEATURE_CMO flag in powerpc_firmware_features from the rtas ibm,get-system-parameters table prior to calling iommu_init_early_pSeries. With this, any CMO specific functionality can be controlled by checking: firmware_has_feature(FW_FEATURE_CMO) Signed-off-by: Robert Jennings <rcj@linux.vnet.ibm.com> Acked-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * | powerpc/pseries: Split retrieval of processor entitlement data into a helper ↵Robert Jennings2008-07-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | routine Split the retrieval of processor entitlement data returned in the H_GET_PPP hcall into its own helper routine. Signed-off-by: Nathan Fontenot <nfont@austin.ibm.com> Signed-off-by: Robert Jennings <rcj@linux.vnet.ibm.com> Acked-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * | powerpc/pseries: Add memory entitlement capabilities to /proc/ppc64/lparcfgNathan Fontenot2008-07-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Update /proc/ppc64/lparcfg to display Cooperative Memory Overcommitment statistics as reported by the H_GET_MPP hcall. This also updates the lparcfg interface to allow setting memory entitlement and weight. Signed-off-by: Nathan Fontenot <nfont@austin.ibm.com> Signed-off-by: Robert Jennings <rcj@linux.vnet.ibm.com> Acked-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * | powerpc/pseries: Split processor entitlement retrieval and gathering to ↵Nathan Fotenot2008-07-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | helper routines Split the retrieval and setting of processor entitlement and weight into helper routines. This also removes the printing of the raw values returned from h_get_ppp, the values are already parsed and printed. Signed-off-by: Nathan Fontenot <nfont@austin.ibm.com> Signed-off-by: Robert Jennings <rcj@linux.vnet.ibm.com> Acked-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * | powerpc/pseries: Remove extraneous error reporting for hcall failures in lparcfgNathan Fontenot2008-07-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | Remove the extraneous error reporting used when a hcall made from lparcfg fails. Signed-off-by: Nathan Fontenot <nfont@austin.ibm.com> Signed-off-by: Robert Jennings <rcj@linux.vnet.ibm.com> Acked-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * | powerpc: Fix compile error with binutils 2.15Segher Boessenkool2008-07-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | My previous patch to fix compilation with binutils-2.17 causes a "file truncated" build error from ld with binutils 2.15 (and possibly older), and a warning with 2.16 and 2.17. This fixes it. Signed-off-by: Segher Boessenkool <segher@kernel.crashing.org> Acked-by: Chuck Meade <chuckmeade@mindspring.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * | powerpc/cell: Fixed IOMMU mapping uses weak ordering for a pcie endpointMark Nelson2008-07-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | At the moment the fixed mapping is by default strongly ordered (the iommu_fixed=weak boot option must be used to make the fixed mapping weakly ordered). If we're on a setup where the southbridge is being used in endpoint mode (triblade and CAB boards) the default should be a weakly ordered fixed mapping. This adds a check so that if a node of type pcie-endpoint can be found in the device tree the fixed mapping is set to be weak by default (but can be overridden using iommu_fixed=strong). Signed-off-by: Mark Nelson <markn@au1.ibm.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * | powerpc: BookE hardware watchpoint supportLuis Machado2008-07-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch implements support for HW based watchpoint via the DBSR_DAC (Data Address Compare) facility of the BookE processors. It does so by interfacing with the existing DABR breakpoint code and adding the necessary bits and pieces for the new bits to be properly set or cleared Signed-off-by: Luis Machado <luisgpm@br.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * | powerpc: Fallout from sysdev API changesStephen Rothwell2008-07-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A struct sysdev_attribute * parameter was added to the show routine by commit 4a0b2b4dbe1335b8b9886ba3dc85a145d5d938ed "sysdev: Pass the attribute to the low level sysdev show/store function". This eliminates a warning: arch/powerpc/kernel/sysfs.c:538: warning: initialization from incompatible pointer type Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * | powerpc: Enable AT_BASE_PLATFORM aux vectorNathan Lynch2008-07-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | Stash the first platform string matched by identify_cpu() in powerpc_base_platform, and supply that to the ELF loader for the value of AT_BASE_PLATFORM. Signed-off-by: Nathan Lynch <ntl@pobox.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
| * | Merge commit 'jk/jk-merge'Benjamin Herrenschmidt2008-07-25
| |\ \
| | * | powerpc/spufs: better placement of spu affinity reference contextAndre Detsch2008-07-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adjusts the placement of a reference context from a spu affinity chain. The reference context can now be placed only on nodes that have enough spus not intended to be used by another gang (already running on the node). Signed-off-by: Andre Detsch <adetsch@br.ibm.com> Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
| | * | powerpc/spufs: fix aff_mutex and cbe_spu_info[n].list_mutex deadlockAndre Detsch2008-07-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currenlt,, it is possible to lock aff_mutex and cbe_spu_info[n].list_mutex in different orders, allowing a deadlock to occur. With this change, aff_mutex is not taken within a list_mutex critical section anymore. Signed-off-by: Andre Detsch <adetsch@br.ibm.com> Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
| | * | powerpc/spufs: correct kcalloc usageMilton Miller2008-07-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | kcalloc is supposed to be called with the count as its first argument and the element size as the second. Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
| * | | Merge commit 'gcl/gcl-next'Benjamin Herrenschmidt2008-07-25
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| | * | powerpc/mpc5200: Make mpc5200 GPIO driver select the GENERIC_GPIO configGrant Likely2008-07-22
| | | | | | | | | | | | | | | | | | | | | | | | CONFIG_GENERIC_GPIO is needed for the gpio driver to work. Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
| | * | powerpc/mpc5200: Remove fsl-soc.c from mpc5200 build, it is not needed.Jon Smirl2008-07-22
| | | | | | | | | | | | | | | | | | | | Signed-off-by: Jon Smirl <jonsmirl@gmail.com> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
* | | | pty: remove unused UNIX98_PTY_COUNT optionsAdrian Bunk2008-07-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The h8300 and sparc options somehow survived when the code stopped using CONFIG_UNIX98_PTY_COUNT. Reviewed-by: Robert P. J. Day <rpjday@crashcourse.ca> Signed-off-by: Adrian Bunk <bunk@kernel.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | calgary iommu: use the first kernels TCE tables in kdumpChandru2008-07-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | kdump kernel fails to boot with calgary iommu and aacraid driver on a x366 box. The ongoing dma's of aacraid from the first kernel continue to exist until the driver is loaded in the kdump kernel. Calgary is initialized prior to aacraid and creation of new tce tables causes wrong dma's to occur. Here we try to get the tce tables of the first kernel in kdump kernel and use them. While in the kdump kernel we do not allocate new tce tables but instead read the base address register contents of calgary iommu and use the tables that the registers point to. With these changes the kdump kernel and hence aacraid now boots normally. Signed-off-by: Chandru Siddalingappa <chandru@in.ibm.com> Acked-by: Muli Ben-Yehuda <muli@il.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | S390 topology: don't use kthread() for arch_reinit_sched_domains()Oleg Nesterov2008-07-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that it is safe to use get_online_cpus() we can revert [S390] cpu topology: Fix possible deadlock. commit: fd781fa25c9e9c6fd1599df060b05e7c4ad724e5 and call arch_reinit_sched_domains() directly from topology_work_fn(). Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Gautham R Shenoy <ego@in.ibm.com> Tested-by: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Max Krasnyansky <maxk@qualcomm.com> Cc: Paul Jackson <pj@sgi.com> Cc: Paul Menage <menage@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Vegard Nossum <vegard.nossum@gmail.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | remove unused #include <linux/dirent.h>'sAdrian Bunk2008-07-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Remove some unused #include <linux/dirent.h>'s. Signed-off-by: Adrian Bunk <bunk@kernel.org> Cc: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | gpiolib: allow user-selectionMichael Buesch2008-07-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds functionality to the gpio-lib subsystem to make it possible to enable the gpio-lib code even if the architecture code didn't request to get it built in. The archtitecture code does still need to implement the gpiolib accessor functions in its asm/gpio.h file. This patch adds the implementations for x86 and PPC. With these changes it is possible to run generic GPIO expansion cards on every architecture that implements the trivial wrapper functions. Support for more architectures can easily be added. Signed-off-by: Michael Buesch <mb@bu3sch.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: David Brownell <david-b@pacbell.net> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Haavard Skinnemoen <hskinnemoen@atmel.com> Cc: Jesper Nilsson <jesper.nilsson@axis.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Jean Delvare <khali@linux-fr.org> Cc: Samuel Ortiz <sameo@openedhand.com> Cc: Kumar Gala <galak@gate.crashing.org> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | gpio: sysfs interfaceDavid Brownell2008-07-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This adds a simple sysfs interface for GPIOs. /sys/class/gpio /export ... asks the kernel to export a GPIO to userspace /unexport ... to return a GPIO to the kernel /gpioN ... for each exported GPIO #N /value ... always readable, writes fail for input GPIOs /direction ... r/w as: in, out (default low); write high, low /gpiochipN ... for each gpiochip; #N is its first GPIO /base ... (r/o) same as N /label ... (r/o) descriptive, not necessarily unique /ngpio ... (r/o) number of GPIOs; numbered N .. N+(ngpio - 1) GPIOs claimed by kernel code may be exported by its owner using a new gpio_export() call, which should be most useful for driver debugging. Such exports may optionally be done without a "direction" attribute. Userspace may ask to take over a GPIO by writing to a sysfs control file, helping to cope with incomplete board support or other "one-off" requirements that don't merit full kernel support: echo 23 > /sys/class/gpio/export ... will gpio_request(23, "sysfs") and gpio_export(23); use /sys/class/gpio/gpio-23/direction to (re)configure it, when that GPIO can be used as both input and output. echo 23 > /sys/class/gpio/unexport ... will gpio_free(23), when it was exported as above The extra D-space footprint is a few hundred bytes, except for the sysfs resources associated with each exported GPIO. The additional I-space footprint is about two thirds of the current size of gpiolib (!). Since no /dev node creation is involved, no "udev" support is needed. Related changes: * This adds a device pointer to "struct gpio_chip". When GPIO providers initialize that, sysfs gpio class devices become children of that device instead of being "virtual" devices. * The (few) gpio_chip providers which have such a device node have been updated. * Some gpio_chip drivers also needed to update their module "owner" field ... for which missing kerneldoc was added. * Some gpio_chips don't support input GPIOs. Those GPIOs are now flagged appropriately when the chip is registered. Based on previous patches, and discussion both on and off LKML. A Documentation/ABI/testing/sysfs-gpio update is ready to submit once this merges to mainline. [akpm@linux-foundation.org: a few maintenance build fixes] Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Cc: Guennadi Liakhovetski <g.liakhovetski@pengutronix.de> Cc: Greg KH <greg@kroah.com> Cc: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | kprobes: improve kretprobe scalability with hashed lockingSrinivasa D S2008-07-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently list of kretprobe instances are stored in kretprobe object (as used_instances,free_instances) and in kretprobe hash table. We have one global kretprobe lock to serialise the access to these lists. This causes only one kretprobe handler to execute at a time. Hence affects system performance, particularly on SMP systems and when return probe is set on lot of functions (like on all systemcalls). Solution proposed here gives fine-grain locks that performs better on SMP system compared to present kretprobe implementation. Solution: 1) Instead of having one global lock to protect kretprobe instances present in kretprobe object and kretprobe hash table. We will have two locks, one lock for protecting kretprobe hash table and another lock for kretporbe object. 2) We hold lock present in kretprobe object while we modify kretprobe instance in kretprobe object and we hold per-hash-list lock while modifying kretprobe instances present in that hash list. To prevent deadlock, we never grab a per-hash-list lock while holding a kretprobe lock. 3) We can remove used_instances from struct kretprobe, as we can track used instances of kretprobe instances using kretprobe hash table. Time duration for kernel compilation ("make -j 8") on a 8-way ppc64 system with return probes set on all systemcalls looks like this. cacheline non-cacheline Un-patched kernel aligned patch aligned patch =============================================================================== real 9m46.784s 9m54.412s 10m2.450s user 40m5.715s 40m7.142s 40m4.273s sys 2m57.754s 2m58.583s 3m17.430s =========================================================== Time duration for kernel compilation ("make -j 8) on the same system, when kernel is not probed. ========================= real 9m26.389s user 40m8.775s sys 2m7.283s ========================= Signed-off-by: Srinivasa DS <srinivasa@in.ibm.com> Signed-off-by: Jim Keniston <jkenisto@us.ibm.com> Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Cc: David S. Miller <davem@davemloft.net> Cc: Masami Hiramatsu <mhiramat@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-25 22:32:02 -0500