user/sven/linux-bitkeeper.git/ipc/util.c, branch master

[PATCH] Lock initializer unifying (Core)

2004-10-28T01:33:04Z

To make spinlock/rwlock initialization consistent all over the kernel, this patch converts explicit lock-initializers into spin_lock_init() and rwlock_init() calls. Currently, spinlocks and rwlocks are initialized in two different ways: lock = SPIN_LOCK_UNLOCKED spin_lock_init(&lock) rwlock = RW_LOCK_UNLOCKED rwlock_init(&rwlock) this patch converts all explicit lock initializations to spin_lock_init() or rwlock_init(). (Besides consistency this also helps automatic lock validators and debugging code.) The conversion was done with a script, it was verified manually and it was reviewed, compiled and tested as far as possible on x86, ARM, PPC. There is no runtime overhead or actual code change resulting out of this patch, because spin_lock_init() and rwlock_init() are macros and are thus equivalent to the explicit initialization method. Signed-off-by: Thomas Gleixner Acked-by: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] RCU: eliminating explicit memory barriers from SysV IPC

2004-10-28T01:28:37Z

This patch uses the rcu_assign_pointer() API to eliminate a number of explicit memory barriers from the SysV IPC code that uses RCU. It also restructures the ipc_ids structure so that the array size is stored in the same memory block as the array itself (see the new struct ipc_id_ary). This prevents the race that the earlier code was subject to, where a reader could see a mismatch between the size and the actual array. With the size stored with the array, the possibility of mismatch is eliminated -- with out the need for careful ordering and explicit memory barriers. This has been tested successfully on i386 and ppc64. Signed-off-by: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] rcu: abstracted RCU dereferencing

2004-08-23T05:58:51Z

Use abstracted RCU API to dereference RCU protected data. Hides barrier details. Patch from Paul McKenney. This patch introduced an rcu_dereference() macro that replaces most uses of smp_read_barrier_depends(). The new macro has the advantage of explicitly documenting which pointers are protected by RCU -- in contrast, it is sometimes difficult to figure out which pointer is being protected by a given smp_read_barrier_depends() call. Signed-off-by: Paul McKenney Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] ipc: Add refcount to ipc_rcu_alloc

2004-08-23T05:40:37Z

The lifetime of the ipc objects (sem array, msg queue, shm mapping) is controlled by kern_ipc_perms->lock - a spinlock. There is no simple way to reacquire this spinlock after it was dropped to schedule()/kmalloc/copy_{to,from}_user/whatever. The attached patch adds a reference count as a preparation to get rid of sem_revalidate(). Signed-Off-By: Manfred Spraul Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] rcu: avoid passing an argument to the callback function

2004-06-24T01:50:18Z

From: Dipankar Sarma This patch changes the call_rcu() API and avoids passing an argument to the callback function as suggested by Rusty. Instead, it is assumed that the user has embedded the rcu head into a structure that is useful in the callback and the rcu_head pointer is passed to the callback. The callback can use container_of() to get the pointer to its structure and work with it. Together with the rcu-singly-link patch, it reduces the rcu_head size by 50%. Considering that we use these in things like struct dentry and struct dst_entry, this is good savings in space. An example : struct my_struct { struct rcu_head rcu; int x; int y; }; void my_rcu_callback(struct rcu_head *head) { struct my_struct *p = container_of(head, struct my_struct, rcu); free(p); } void my_delete(struct my_struct *p) { ... call_rcu(&p->rcu, my_rcu_callback); ... } Signed-Off-By: Dipankar Sarma Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] Sanitise handling of unneeded syscall stubs

2004-05-22T03:38:29Z

From: David Mosberger Below is a patch that tries to sanitize the dropping of unneeded system-call stubs in generic code. In some instances, it would be possible to move the optional system-call stubs into a library routine which would avoid the need for #ifdefs, but in many cases, doing so would require making several functions global (and possibly exporting additional data-structures in header-files). Furthermore, it would inhibit (automatic) inlining in the cases in the cases where the stubs are needed. For these reasons, the patch keeps the #ifdef-approach. This has been tested on ia64 and there were no objections from the arch-maintainers (and one positive response). The patch should be safe but arch-maintainers may want to take a second look to see if some __ARCH_WANT_foo macros should be removed for their architecture (I'm quite sure that's the case, but I wanted to play it safe and only preserved the status-quo in that regard).

[PATCH] posix message queues: code move

2004-04-12T05:53:50Z

From: Manfred Spraul cleanup of sysv ipc as a preparation for posix message queues: - replace !CONFIG_SYSVIPC wrappers for copy_semundo and exit_sem with static inline wrappers. Now the whole ipc/util.c file is only used if CONFIG_SYSVIPC is set, use makefile magic instead of #ifdef. - remove the prototypes for copy_semundo and exit_sem from kernel/fork.c - they belong into a header file. - create a new msgutil.c with the helper functions for message queues. - cleanup the helper functions: run Lindent, add __user tags.

[PATCH] cleanup condsyscall for sysv ipc

2004-02-22T15:05:38Z

From: Manfred Spraul Attached is a patch that replaces the #ifndef CONFIG_SYSV syscall stubs with cond_syscall stubs.

[PATCH] PA-RISC needs IPC64 structs

2004-02-06T11:44:47Z

PA-RISC also uses the 64-bit version of the IPC structs.

[PATCH] UID16 fixes

2003-10-06T08:15:36Z

This fixes CONFIG_UID16 problems on x86-64 as discussed earlier. CONFIG_UID16 now only selects the inclusion of kernel/uid16.c, all conversions are triggered dynamically based on type sizes. This allows x86-64 to both include uid16.c for emulation purposes, but not truncate uids to 16bit in sys_newstat. - Replace the old macros from linux/highuid.h with new SET_UID/SET_GID macros that do type checking. Based on Linus' proposal. - Fix everybody to use them. - Clean up some cruft in the x86-64 32bit emulation allowed by this (other 32bit emulations could be cleaned too, but I'm too lazy for that right now) - Add one missing EOVERFLOW check in x86-64 32bit sys_newstat while I was at it.