- 01 May, 2013 40 commits
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Linus Torvalds authored
Merge IPC cleanup and scalability patches from Andrew Morton. This cleans up many of the oddities in the IPC code, uses the list iterator helpers, splits out locking and adds per-semaphore locks for greater scalability of the IPC semaphore code. Most normal user-level locking by now uses futexes (ie pthreads, but also a lot of specialized locks), but SysV IPC semaphores are apparently still used in some big applications, either for portability reasons, or because they offer tracking and undo (and you don't need to have a special shared memory area for them). Our IPC semaphore scalability was pitiful. We used to lock much too big ranges, and we used to have a single ipc lock per ipc semaphore array. Most loads never cared, but some do. There are some numbers in the individual commits. * ipc-scalability: ipc: sysv shared memory limited to 8TiB ipc/msg.c: use list_for_each_entry_[safe] for list traversing ipc,sem: fine grained locking for semtimedop ipc,sem: have only one list in struct sem_queue ipc,sem: open code and rename sem_lock ipc,sem: do not hold ipc lock more than necessary ipc: introduce lockless pre_down ipcctl ipc: introduce obtaining a lockless ipc object ipc: remove bogus lock comment for ipc_checkid ipc/msgutil.c: use linux/uaccess.h ipc: refactor msg list search into separate function ipc: simplify msg list search ipc: implement MSG_COPY as a new receive mode ipc: remove msg handling from queue scan ipc: set EFAULT as default error in load_msg() ipc: tighten msg copy loops ipc: separate msg allocation from userspace copy ipc: clamp with min()
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Robin Holt authored
Trying to run an application which was trying to put data into half of memory using shmget(), we found that having a shmall value below 8EiB-8TiB would prevent us from using anything more than 8TiB. By setting kernel.shmall greater than 8EiB-8TiB would make the job work. In the newseg() function, ns->shm_tot which, at 8TiB is INT_MAX. ipc/shm.c: 458 static int newseg(struct ipc_namespace *ns, struct ipc_params *params) 459 { ... 465 int numpages = (size + PAGE_SIZE -1) >> PAGE_SHIFT; ... 474 if (ns->shm_tot + numpages > ns->shm_ctlall) 475 return -ENOSPC; [akpm@linux-foundation.org: make ipc/shm.c:newseg()'s numpages size_t, not int] Signed-off-by:Robin Holt <holt@sgi.com> Reported-by:
Alex Thorlton <athorlton@sgi.com> Cc: <stable@vger.kernel.org> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Nikola Pajkovsky authored
The ipc/msg.c code does its list operations by hand and it open-codes the accesses, instead of using for_each_entry_[safe]. Signed-off-by:
Nikola Pajkovsky <npajkovs@redhat.com> Cc: Stanislav Kinsbursky <skinsbursky@parallels.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Peter Hurley <peter@hurleysoftware.com> Signed-off-by:
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Rik van Riel authored
Introduce finer grained locking for semtimedop, to handle the common case of a program wanting to manipulate one semaphore from an array with multiple semaphores. If the call is a semop manipulating just one semaphore in an array with multiple semaphores, only take the lock for that semaphore itself. If the call needs to manipulate multiple semaphores, or another caller is in a transaction that manipulates multiple semaphores, the sem_array lock is taken, as well as all the locks for the individual semaphores. On a 24 CPU system, performance numbers with the semop-multi test with N threads and N semaphores, look like this: vanilla Davidlohr's Davidlohr's + Davidlohr's + threads patches rwlock patches v3 patches 10 610652 726325 1783589 2142206 20 341570 365699 1520453 1977878 30 288102 307037 1498167 2037995 40 290714 305955 1612665 2256484 50 288620 312890 1733453 2650292 60 289987 306043 1649360 2388008 70 291298 306347 1723167 2717486 80 290948 305662 1729545 2763582 90 290996 306680 1736021 2757524 100 292243 306700 1773700 3059159 [davidlohr.bueso@hp.com: do not call sem_lock when bogus sma] [davidlohr.bueso@hp.com: make refcounter atomic] Signed-off-by:
Rik van Riel <riel@redhat.com> Suggested-by:
Davidlohr Bueso <davidlohr.bueso@hp.com> Cc: Chegu Vinod <chegu_vinod@hp.com> Cc: Jason Low <jason.low2@hp.com> Reviewed-by:
Michel Lespinasse <walken@google.com> Cc: Peter Hurley <peter@hurleysoftware.com> Cc: Stanislav Kinsbursky <skinsbursky@parallels.com> Tested-by:
Emmanuel Benisty <benisty.e@gmail.com> Tested-by:
Sedat Dilek <sedat.dilek@gmail.com> Signed-off-by:
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Rik van Riel authored
Having only one list in struct sem_queue, and only queueing simple semaphore operations on the list for the semaphore involved, allows us to introduce finer grained locking for semtimedop. Signed-off-by:
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Rik van Riel authored
Rename sem_lock() to sem_obtain_lock(), so we can introduce a sem_lock() later that only locks the sem_array and does nothing else. Open code the locking from ipc_lock() in sem_obtain_lock() so we can introduce finer grained locking for the sem_array in the next patch. [akpm@linux-foundation.org: propagate the ipc_obtain_object() errno out of sem_obtain_lock()] Signed-off-by:
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Davidlohr Bueso authored
Instead of holding the ipc lock for permissions and security checks, among others, only acquire it when necessary. Some numbers.... 1) With Rik's semop-multi.c microbenchmark we can see the following results: Baseline (3.9-rc1): cpus 4, threads: 256, semaphores: 128, test duration: 30 secs total operations: 151452270, ops/sec 5048409 + 59.40% a.out [kernel.kallsyms] [k] _raw_spin_lock + 6.14% a.out [kernel.kallsyms] [k] sys_semtimedop + 3.84% a.out [kernel.kallsyms] [k] avc_has_perm_flags + 3.64% a.out [kernel.kallsyms] [k] __audit_syscall_exit + 2.06% a.out [kernel.kallsyms] [k] copy_user_enhanced_fast_string + 1.86% a.out [kernel.kallsyms] [k] ipc_lock With this patchset: cpus 4, threads: 256, semaphores: 128, test duration: 30 secs total operations: 273156400, ops/sec 9105213 + 18.54% a.out [kernel.kallsyms] [k] _raw_spin_lock + 11.72% a.out [kernel.kallsyms] [k] sys_semtimedop + 7.70% a.out [kernel.kallsyms] [k] ipc_has_perm.isra.21 + 6.58% a.out [kernel.kallsyms] [k] avc_has_perm_flags + 6.54% a.out [kernel.kallsyms] [k] __audit_syscall_exit + 4.71% a.out [kernel.kallsyms] [k] ipc_obtain_object_check 2) While on an Oracle swingbench DSS (data mining) workload the improvements are not as exciting as with Rik's benchmark, we can see some positive numbers. For an 8 socket machine the following are the percentages of %sys time incurred in the ipc lock: Baseline (3.9-rc1): 100 swingbench users: 8,74% 400 swingbench users: 21,86% 800 swingbench users: 84,35% With this patchset: 100 swingbench users: 8,11% 400 swingbench users: 19,93% 800 swingbench users: 77,69% [riel@redhat.com: fix two locking bugs] [sasha.levin@oracle.com: prevent releasing RCU read lock twice in semctl_main] [akpm@linux-foundation.org: coding-style fixes] Signed-off-by:
Chegu Vinod <chegu_vinod@hp.com> Acked-by:
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Davidlohr Bueso authored
Various forms of ipc use ipcctl_pre_down() to retrieve an ipc object and check permissions, mostly for IPC_RMID and IPC_SET commands. Introduce ipcctl_pre_down_nolock(), a lockless version of this function. The locking version is retained, yet modified to call the nolock version without affecting its semantics, thus transparent to all ipc callers. Signed-off-by:
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Davidlohr Bueso authored
Through ipc_lock() and therefore ipc_lock_check() we currently return the locked ipc object. This is not necessary for all situations and can, therefore, cause unnecessary ipc lock contention. Introduce analogous ipc_obtain_object() and ipc_obtain_object_check() functions that only lookup and return the ipc object. Both these functions must be called within the RCU read critical section. [akpm@linux-foundation.org: propagate the ipc_obtain_object() errno from ipc_lock()] Signed-off-by:
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Davidlohr Bueso authored
This series makes the sysv semaphore code more scalable, by reducing the time the semaphore lock is held, and making the locking more scalable for semaphore arrays with multiple semaphores. The first four patches were written by Davidlohr Buesso, and reduce the hold time of the semaphore lock. The last three patches change the sysv semaphore code locking to be more fine grained, providing a performance boost when multiple semaphores in a semaphore array are being manipulated simultaneously. On a 24 CPU system, performance numbers with the semop-multi test with N threads and N semaphores, look like this: vanilla Davidlohr's Davidlohr's + Davidlohr's + threads patches rwlock patches v3 patches 10 610652 726325 1783589 2142206 20 341570 365699 1520453 1977878 30 288102 307037 1498167 2037995 40 290714 305955 1612665 2256484 50 288620 312890 1733453 2650292 60 289987 306043 1649360 2388008 70 291298 306347 1723167 2717486 80 290948 305662 1729545 2763582 90 290996 306680 1736021 2757524 100 292243 306700 1773700 3059159 This patch: There is no reason to be holding the ipc lock while reading ipcp->seq, hence remove misleading comment. Also simplify the return value for the function. Signed-off-by:
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HoSung Jung authored
Signed-off-by:
HoSung Jung <rain6557@gmail.com> Signed-off-by:
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Peter Hurley authored
[fengguang.wu@intel.com: find_msg can be static] Signed-off-by:
Peter Hurley <peter@hurleysoftware.com> Cc: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by:
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Peter Hurley authored
Signed-off-by:
Stanislav Kinsbursky <skinsbursky@parallels.com> Signed-off-by:
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Peter Hurley authored
Teach the helper routines about MSG_COPY so that msgtyp is preserved as the message number to copy. The security functions affected by this change were audited and no additional changes are necessary. Signed-off-by:
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Peter Hurley authored
In preparation for refactoring the queue scan into a separate function, relocate msg copying. Signed-off-by:
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Peter Hurley authored
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Peter Hurley authored
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Peter Hurley authored
Separating msg allocation enables single-block vmalloc allocation instead. Signed-off-by:
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Peter Hurley authored
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git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4Linus Torvalds authored
Pull ext4 updates from Ted Ts'o: "Mostly performance and bug fixes, plus some cleanups. The one new feature this merge window is a new ioctl EXT4_IOC_SWAP_BOOT which allows installation of a hidden inode designed for boot loaders." * tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (50 commits) ext4: fix type-widening bug in inode table readahead code ext4: add check for inodes_count overflow in new resize ioctl ext4: fix Kconfig documentation for CONFIG_EXT4_DEBUG ext4: fix online resizing for ext3-compat file systems jbd2: trace when lock_buffer in do_get_write_access takes a long time ext4: mark metadata blocks using bh flags buffer: add BH_Prio and BH_Meta flags ext4: mark all metadata I/O with REQ_META ext4: fix readdir error in case inline_data+^dir_index. ext4: fix readdir error in the case of inline_data+dir_index jbd2: use kmem_cache_zalloc instead of kmem_cache_alloc/memset ext4: mext_insert_extents should update extent block checksum ext4: move quota initialization out of inode allocation transaction ext4: reserve xattr index for Rich ACL support jbd2: reduce journal_head size ext4: clear buffer_uninit flag when submitting IO ext4: use io_end for multiple bios ext4: make ext4_bio_write_page() use BH_Async_Write flags ext4: Use kstrtoul() instead of parse_strtoul() ext4: defragmentation code cleanup ...
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git://git.linaro.org/people/sumitsemwal/linux-dma-bufLinus Torvalds authored
Pull dma-buf updates from Sumit Semwal: "Added debugfs support to dma-buf" * tag 'tag-for-linus-3.10' of git://git.linaro.org/people/sumitsemwal/linux-dma-buf: dma-buf: Add debugfs support dma-buf: replace dma_buf_export() with dma_buf_export_named()
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git://git.kernel.org/pub/scm/linux/kernel/git/rkuo/linux-hexagon-kernelLinus Torvalds authored
Pull Hexagon fixes from Richard Kuo: "Changes for the Hexagon architecture (and one touching OpenRISC). They include various fixes to make use of additional arch features and cleanups. The largest functional change is a cleanup of the signal and event return paths" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rkuo/linux-hexagon-kernel: (32 commits) Hexagon: add v4 CS regs to core copyout macro Hexagon: use correct translation for VMALLOC_START Hexagon: use correct translations for DMA mappings Hexagon: fix return value for notify_resume case in do_work_pending Hexagon: fix signal number for user mem faults Hexagon: remove two Kconfig entries arch: remove CONFIG_GENERIC_FIND_NEXT_BIT again Hexagon: update copyright dates Hexagon: add translation types for __vmnewmap Hexagon: fix signal.c compile error Hexagon: break up user fn/arg register setting Hexagon: use generic sys_fork, sys_vfork, and sys_clone Hexagon: fix psp/sp macro Hexagon: fix up int enable/disable at ret_from_fork Hexagon: add IOMEM and _relaxed IO macros Hexagon: switch to using the device type for IO mappings Hexagon: don't print info for offline CPU's Hexagon: add support for single-stepping (v4+) Hexagon: use correct work mask when checking for more work Hexagon: add support for additional exceptions ...
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Linus Torvalds authored
We first tried to avoid updating atime/mtime entirely (commit b0de59b5: "TTY: do not update atime/mtime on read/write"), and then limited it to only update it occasionally (commit 37b7f3c7: "TTY: fix atime/mtime regression"), but it turns out that this was both insufficient and overkill. It was insufficient because we let people attach to the shared ptmx node to see activity without even reading atime/mtime, and it was overkill because the "only once a minute" means that you can't really tell an idle person from an active one with 'w'. So this tries to fix the problem properly. It marks the shared ptmx node as un-notifiable, and it lowers the "only once a minute" to a few seconds instead - still long enough that you can't time individual keystrokes, but short enough that you can tell whether somebody is active or not. Reported-by:
Simon Kirby <sim@hostway.ca> Acked-by:
Jiri Slaby <jslaby@suse.cz> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: stable@vger.kernel.org Signed-off-by:
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git://git.kernel.org/pub/scm/linux/kernel/git/viro/signalLinus Torvalds authored
Pull compat cleanup from Al Viro: "Mostly about syscall wrappers this time; there will be another pile with patches in the same general area from various people, but I'd rather push those after both that and vfs.git pile are in." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: syscalls.h: slightly reduce the jungles of macros get rid of union semop in sys_semctl(2) arguments make do_mremap() static sparc: no need to sign-extend in sync_file_range() wrapper ppc compat wrappers for add_key(2) and request_key(2) are pointless x86: trim sys_ia32.h x86: sys32_kill and sys32_mprotect are pointless get rid of compat_sys_semctl() and friends in case of ARCH_WANT_OLD_COMPAT_IPC merge compat sys_ipc instances consolidate compat lookup_dcookie() convert vmsplice to COMPAT_SYSCALL_DEFINE switch getrusage() to COMPAT_SYSCALL_DEFINE switch epoll_pwait to COMPAT_SYSCALL_DEFINE convert sendfile{,64} to COMPAT_SYSCALL_DEFINE switch signalfd{,4}() to COMPAT_SYSCALL_DEFINE make SYSCALL_DEFINE<n>-generated wrappers do asmlinkage_protect make HAVE_SYSCALL_WRAPPERS unconditional consolidate cond_syscall and SYSCALL_ALIAS declarations teach SYSCALL_DEFINE<n> how to deal with long long/unsigned long long get rid of duplicate logics in __SC_....[1-6] definitions
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Sumit Semwal authored
Add debugfs support to make it easier to print debug information about the dma-buf buffers. Cc: Dave Airlie <airlied@redhat.com> [minor fixes on init and warning fix] Cc: Dan Carpenter <dan.carpenter@oracle.com> [remove double unlock in fail case] Signed-off-by:Sumit Semwal <sumit.semwal@linaro.org>
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Sumit Semwal authored
For debugging purposes, it is useful to have a name-string added while exporting buffers. Hence, dma_buf_export() is replaced with dma_buf_export_named(), which additionally takes 'exp_name' as a parameter. For backward compatibility, and for lazy exporters who don't wish to name themselves, a #define dma_buf_export() is also made available, which adds a __FILE__ instead of 'exp_name'. Cc: Daniel Vetter <daniel.vetter@ffwll.ch> [Thanks for the idea!] Reviewed-by:
Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by:
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Richard Kuo authored
Signed-off-by:Richard Kuo <rkuo@codeaurora.org>
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Richard Kuo authored
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Richard Kuo authored
With physical offsets, pa<->va translations aren't just based on PAGE_OFFSET anymore. Signed-off-by: -
Richard Kuo authored
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Richard Kuo authored
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Paul Bolle authored
The Kconfig entries for HEXAGON_VM and HEXAGON_ANGEL_TRAPS were added, together with the configuration and makefiles for the Hexagon architecture, in v3.2. They have never been used. They can safely be removed. Signed-off-by:
Paul Bolle <pebolle@tiscali.nl> [rkuo@codeaurora.org: adjust for line changes in Kconfig] Signed-off-by:
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Paul Bolle authored
CONFIG_GENERIC_FIND_NEXT_BIT was removed in v3.0, but reappeared in two architectures. Remove it again. Signed-off-by:
Jonas Bonn <jonas@southpole.se> Signed-off-by:
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Richard Kuo authored
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Richard Kuo authored
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Richard Kuo authored
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Richard Kuo authored
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Richard Kuo authored
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Richard Kuo authored
Based on feedback from Al Viro; previous-stack-pointer and user reg for same should always be kept consistent. Signed-off-by: -
Richard Kuo authored
Check return coming out of check_work_pending, and if copy_thread passed us a function in r24, call it. Based on feedback from Al Viro. Signed-off-by:
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