1. 30 7月, 2009 1 次提交
    • D
      lib: flexible array implementation · 534acc05
      Dave Hansen 提交于
      Once a structure goes over PAGE_SIZE*2, we see occasional allocation
      failures.  Some people have chosen to switch over to things like vmalloc()
      that will let them keep array-like access to such a large structures.
      But, vmalloc() has plenty of downsides.
      
      Here's an alternative.  I think it's what Andrew was suggesting here:
      
      	http://lkml.org/lkml/2009/7/2/518
      
      I call it a flexible array.  It does all of its work in PAGE_SIZE bits, so
      never does an order>0 allocation.  The base level has
      PAGE_SIZE-2*sizeof(int) bytes of storage for pointers to the second level.
       So, with a 32-bit arch, you get about 4MB (4183112 bytes) of total
      storage when the objects pack nicely into a page.  It is half that on
      64-bit because the pointers are twice the size.  There's a table detailing
      this in the code.
      
      There are kerneldocs for the functions, but here's an
      overview:
      
      flex_array_alloc() - dynamically allocate a base structure
      flex_array_free() - free the array and all of the
      		    second-level pages
      flex_array_free_parts() - free the second-level pages, but
      			  not the base (for static bases)
      flex_array_put() - copy into the array at the given index
      flex_array_get() - copy out of the array at the given index
      flex_array_prealloc() - preallocate the second-level pages
      			between the given indexes to
      			guarantee no allocs will occur at
      			put() time.
      
      We could also potentially just pass the "element_size" into each of the
      API functions instead of storing it internally.  That would get us one
      more base pointer on 32-bit.
      
      I've been testing this by running it in userspace.  The header and patch
      that I've been using are here, as well as the little script I'm using to
      generate the size table which goes in the kerneldocs.
      
      	http://sr71.net/~dave/linux/flexarray/
      
      [akpm@linux-foundation.org: coding-style fixes]
      Signed-off-by: NDave Hansen <dave@linux.vnet.ibm.com>
      Reviewed-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      534acc05
  2. 19 6月, 2009 1 次提交
    • F
      lib: add lib/gcd.c · d2829224
      Florian Fainelli 提交于
      This patch adds lib/gcd.c which contains a greatest common divider
      implementation taken from sound/core/pcm_timer.c
      
      Several usages of this new library function will be sent to subsystem
      maintainers.
      
      [akpm@linux-foundation.org: use swap() (pointed out by Joe)]
      [akpm@linux-foundation.org: just add gcd.o to obj-y, remove Kconfig changes]
      Signed-off-by: NFlorian Fainelli <florian@openwrt.org>
      Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com>
      Cc: Takashi Iwai <tiwai@suse.de>
      Cc: Simon Horman <horms@verge.net.au>
      Cc: Julius Volz <juliusv@google.com>
      Cc: David S. Miller <davem@davemloft.net>
      Cc: Patrick McHardy <kaber@trash.net>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      d2829224
  3. 15 6月, 2009 1 次提交
    • P
      lib: Provide generic atomic64_t implementation · 09d4e0ed
      Paul Mackerras 提交于
      Many processor architectures have no 64-bit atomic instructions, but
      we need atomic64_t in order to support the perf_counter subsystem.
      
      This adds an implementation of 64-bit atomic operations using hashed
      spinlocks to provide atomicity.  For each atomic operation, the address
      of the atomic64_t variable is hashed to an index into an array of 16
      spinlocks.  That spinlock is taken (with interrupts disabled) around the
      operation, which can then be coded non-atomically within the lock.
      
      On UP, all the spinlock manipulation goes away and we simply disable
      interrupts around each operation.  In fact gcc eliminates the whole
      atomic64_lock variable as well.
      Signed-off-by: NPaul Mackerras <paulus@samba.org>
      Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
      09d4e0ed
  4. 12 6月, 2009 1 次提交
  5. 11 6月, 2009 1 次提交
  6. 25 4月, 2009 1 次提交
  7. 25 3月, 2009 1 次提交
    • J
      dynamic debug: combine dprintk and dynamic printk · e9d376f0
      Jason Baron 提交于
      This patch combines Greg Bank's dprintk() work with the existing dynamic
      printk patchset, we are now calling it 'dynamic debug'.
      
      The new feature of this patchset is a richer /debugfs control file interface,
      (an example output from my system is at the bottom), which allows fined grained
      control over the the debug output. The output can be controlled by function,
      file, module, format string, and line number.
      
      for example, enabled all debug messages in module 'nf_conntrack':
      
      echo -n 'module nf_conntrack +p' > /mnt/debugfs/dynamic_debug/control
      
      to disable them:
      
      echo -n 'module nf_conntrack -p' > /mnt/debugfs/dynamic_debug/control
      
      A further explanation can be found in the documentation patch.
      Signed-off-by: NGreg Banks <gnb@sgi.com>
      Signed-off-by: NJason Baron <jbaron@redhat.com>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
      e9d376f0
  8. 05 3月, 2009 1 次提交
  9. 04 3月, 2009 1 次提交
  10. 16 1月, 2009 1 次提交
    • P
      sched: make plist a library facility · ceacc2c1
      Peter Zijlstra 提交于
      Ingo Molnar wrote:
      
      > here's a new build failure with tip/sched/rt:
      >
      >   LD      .tmp_vmlinux1
      > kernel/built-in.o: In function `set_curr_task_rt':
      > sched.c:(.text+0x3675): undefined reference to `plist_del'
      > kernel/built-in.o: In function `pick_next_task_rt':
      > sched.c:(.text+0x37ce): undefined reference to `plist_del'
      > kernel/built-in.o: In function `enqueue_pushable_task':
      > sched.c:(.text+0x381c): undefined reference to `plist_del'
      
      Eliminate the plist library kconfig and make it available
      unconditionally.
      Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      ceacc2c1
  11. 09 1月, 2009 1 次提交
  12. 06 1月, 2009 1 次提交
  13. 05 1月, 2009 1 次提交
    • A
      bzip2/lzma: config and initramfs support for bzip2/lzma decompression · 30d65dbf
      Alain Knaff 提交于
      Impact: New code for initramfs decompression, new features
      
      This is the second part of the bzip2/lzma patch
      
      The bzip patch is based on an idea by Christian Ludwig, includes support for
      compressing the kernel with bzip2 or lzma rather than gzip. Both
      compressors give smaller sizes than gzip.  Lzma's decompresses faster
      than bzip2.
      
      It also supports ramdisks and initramfs' compressed using these two
      compressors.
      
      The functionality has been successfully used for a couple of years by
      the udpcast project
      
      This version applies to "tip" kernel 2.6.28
      
      This part contains:
      - support for new compressions (bzip2 and lzma) in initramfs and
      old-style ramdisk
      - config dialog for kernel compression (but new kernel compressions
      not yet supported)
      Signed-off-by: NAlain Knaff <alain@knaff.lu>
      Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
      30d65dbf
  14. 01 1月, 2009 1 次提交
  15. 14 11月, 2008 1 次提交
    • D
      CRED: Inaugurate COW credentials · d84f4f99
      David Howells 提交于
      Inaugurate copy-on-write credentials management.  This uses RCU to manage the
      credentials pointer in the task_struct with respect to accesses by other tasks.
      A process may only modify its own credentials, and so does not need locking to
      access or modify its own credentials.
      
      A mutex (cred_replace_mutex) is added to the task_struct to control the effect
      of PTRACE_ATTACHED on credential calculations, particularly with respect to
      execve().
      
      With this patch, the contents of an active credentials struct may not be
      changed directly; rather a new set of credentials must be prepared, modified
      and committed using something like the following sequence of events:
      
      	struct cred *new = prepare_creds();
      	int ret = blah(new);
      	if (ret < 0) {
      		abort_creds(new);
      		return ret;
      	}
      	return commit_creds(new);
      
      There are some exceptions to this rule: the keyrings pointed to by the active
      credentials may be instantiated - keyrings violate the COW rule as managing
      COW keyrings is tricky, given that it is possible for a task to directly alter
      the keys in a keyring in use by another task.
      
      To help enforce this, various pointers to sets of credentials, such as those in
      the task_struct, are declared const.  The purpose of this is compile-time
      discouragement of altering credentials through those pointers.  Once a set of
      credentials has been made public through one of these pointers, it may not be
      modified, except under special circumstances:
      
        (1) Its reference count may incremented and decremented.
      
        (2) The keyrings to which it points may be modified, but not replaced.
      
      The only safe way to modify anything else is to create a replacement and commit
      using the functions described in Documentation/credentials.txt (which will be
      added by a later patch).
      
      This patch and the preceding patches have been tested with the LTP SELinux
      testsuite.
      
      This patch makes several logical sets of alteration:
      
       (1) execve().
      
           This now prepares and commits credentials in various places in the
           security code rather than altering the current creds directly.
      
       (2) Temporary credential overrides.
      
           do_coredump() and sys_faccessat() now prepare their own credentials and
           temporarily override the ones currently on the acting thread, whilst
           preventing interference from other threads by holding cred_replace_mutex
           on the thread being dumped.
      
           This will be replaced in a future patch by something that hands down the
           credentials directly to the functions being called, rather than altering
           the task's objective credentials.
      
       (3) LSM interface.
      
           A number of functions have been changed, added or removed:
      
           (*) security_capset_check(), ->capset_check()
           (*) security_capset_set(), ->capset_set()
      
           	 Removed in favour of security_capset().
      
           (*) security_capset(), ->capset()
      
           	 New.  This is passed a pointer to the new creds, a pointer to the old
           	 creds and the proposed capability sets.  It should fill in the new
           	 creds or return an error.  All pointers, barring the pointer to the
           	 new creds, are now const.
      
           (*) security_bprm_apply_creds(), ->bprm_apply_creds()
      
           	 Changed; now returns a value, which will cause the process to be
           	 killed if it's an error.
      
           (*) security_task_alloc(), ->task_alloc_security()
      
           	 Removed in favour of security_prepare_creds().
      
           (*) security_cred_free(), ->cred_free()
      
           	 New.  Free security data attached to cred->security.
      
           (*) security_prepare_creds(), ->cred_prepare()
      
           	 New. Duplicate any security data attached to cred->security.
      
           (*) security_commit_creds(), ->cred_commit()
      
           	 New. Apply any security effects for the upcoming installation of new
           	 security by commit_creds().
      
           (*) security_task_post_setuid(), ->task_post_setuid()
      
           	 Removed in favour of security_task_fix_setuid().
      
           (*) security_task_fix_setuid(), ->task_fix_setuid()
      
           	 Fix up the proposed new credentials for setuid().  This is used by
           	 cap_set_fix_setuid() to implicitly adjust capabilities in line with
           	 setuid() changes.  Changes are made to the new credentials, rather
           	 than the task itself as in security_task_post_setuid().
      
           (*) security_task_reparent_to_init(), ->task_reparent_to_init()
      
           	 Removed.  Instead the task being reparented to init is referred
           	 directly to init's credentials.
      
      	 NOTE!  This results in the loss of some state: SELinux's osid no
      	 longer records the sid of the thread that forked it.
      
           (*) security_key_alloc(), ->key_alloc()
           (*) security_key_permission(), ->key_permission()
      
           	 Changed.  These now take cred pointers rather than task pointers to
           	 refer to the security context.
      
       (4) sys_capset().
      
           This has been simplified and uses less locking.  The LSM functions it
           calls have been merged.
      
       (5) reparent_to_kthreadd().
      
           This gives the current thread the same credentials as init by simply using
           commit_thread() to point that way.
      
       (6) __sigqueue_alloc() and switch_uid()
      
           __sigqueue_alloc() can't stop the target task from changing its creds
           beneath it, so this function gets a reference to the currently applicable
           user_struct which it then passes into the sigqueue struct it returns if
           successful.
      
           switch_uid() is now called from commit_creds(), and possibly should be
           folded into that.  commit_creds() should take care of protecting
           __sigqueue_alloc().
      
       (7) [sg]et[ug]id() and co and [sg]et_current_groups.
      
           The set functions now all use prepare_creds(), commit_creds() and
           abort_creds() to build and check a new set of credentials before applying
           it.
      
           security_task_set[ug]id() is called inside the prepared section.  This
           guarantees that nothing else will affect the creds until we've finished.
      
           The calling of set_dumpable() has been moved into commit_creds().
      
           Much of the functionality of set_user() has been moved into
           commit_creds().
      
           The get functions all simply access the data directly.
      
       (8) security_task_prctl() and cap_task_prctl().
      
           security_task_prctl() has been modified to return -ENOSYS if it doesn't
           want to handle a function, or otherwise return the return value directly
           rather than through an argument.
      
           Additionally, cap_task_prctl() now prepares a new set of credentials, even
           if it doesn't end up using it.
      
       (9) Keyrings.
      
           A number of changes have been made to the keyrings code:
      
           (a) switch_uid_keyring(), copy_keys(), exit_keys() and suid_keys() have
           	 all been dropped and built in to the credentials functions directly.
           	 They may want separating out again later.
      
           (b) key_alloc() and search_process_keyrings() now take a cred pointer
           	 rather than a task pointer to specify the security context.
      
           (c) copy_creds() gives a new thread within the same thread group a new
           	 thread keyring if its parent had one, otherwise it discards the thread
           	 keyring.
      
           (d) The authorisation key now points directly to the credentials to extend
           	 the search into rather pointing to the task that carries them.
      
           (e) Installing thread, process or session keyrings causes a new set of
           	 credentials to be created, even though it's not strictly necessary for
           	 process or session keyrings (they're shared).
      
      (10) Usermode helper.
      
           The usermode helper code now carries a cred struct pointer in its
           subprocess_info struct instead of a new session keyring pointer.  This set
           of credentials is derived from init_cred and installed on the new process
           after it has been cloned.
      
           call_usermodehelper_setup() allocates the new credentials and
           call_usermodehelper_freeinfo() discards them if they haven't been used.  A
           special cred function (prepare_usermodeinfo_creds()) is provided
           specifically for call_usermodehelper_setup() to call.
      
           call_usermodehelper_setkeys() adjusts the credentials to sport the
           supplied keyring as the new session keyring.
      
      (11) SELinux.
      
           SELinux has a number of changes, in addition to those to support the LSM
           interface changes mentioned above:
      
           (a) selinux_setprocattr() no longer does its check for whether the
           	 current ptracer can access processes with the new SID inside the lock
           	 that covers getting the ptracer's SID.  Whilst this lock ensures that
           	 the check is done with the ptracer pinned, the result is only valid
           	 until the lock is released, so there's no point doing it inside the
           	 lock.
      
      (12) is_single_threaded().
      
           This function has been extracted from selinux_setprocattr() and put into
           a file of its own in the lib/ directory as join_session_keyring() now
           wants to use it too.
      
           The code in SELinux just checked to see whether a task shared mm_structs
           with other tasks (CLONE_VM), but that isn't good enough.  We really want
           to know if they're part of the same thread group (CLONE_THREAD).
      
      (13) nfsd.
      
           The NFS server daemon now has to use the COW credentials to set the
           credentials it is going to use.  It really needs to pass the credentials
           down to the functions it calls, but it can't do that until other patches
           in this series have been applied.
      Signed-off-by: NDavid Howells <dhowells@redhat.com>
      Acked-by: NJames Morris <jmorris@namei.org>
      Signed-off-by: NJames Morris <jmorris@namei.org>
      d84f4f99
  16. 21 10月, 2008 1 次提交
  17. 17 10月, 2008 1 次提交
    • J
      driver core: basic infrastructure for per-module dynamic debug messages · 346e15be
      Jason Baron 提交于
      Base infrastructure to enable per-module debug messages.
      
      I've introduced CONFIG_DYNAMIC_PRINTK_DEBUG, which when enabled centralizes
      control of debugging statements on a per-module basis in one /proc file,
      currently, <debugfs>/dynamic_printk/modules. When, CONFIG_DYNAMIC_PRINTK_DEBUG,
      is not set, debugging statements can still be enabled as before, often by
      defining 'DEBUG' for the proper compilation unit. Thus, this patch set has no
      affect when CONFIG_DYNAMIC_PRINTK_DEBUG is not set.
      
      The infrastructure currently ties into all pr_debug() and dev_dbg() calls. That
      is, if CONFIG_DYNAMIC_PRINTK_DEBUG is set, all pr_debug() and dev_dbg() calls
      can be dynamically enabled/disabled on a per-module basis.
      
      Future plans include extending this functionality to subsystems, that define 
      their own debug levels and flags.
      
      Usage:
      
      Dynamic debugging is controlled by the debugfs file, 
      <debugfs>/dynamic_printk/modules. This file contains a list of the modules that
      can be enabled. The format of the file is as follows:
      
      	<module_name> <enabled=0/1>
      		.
      		.
      		.
      
      	<module_name> : Name of the module in which the debug call resides
      	<enabled=0/1> : whether the messages are enabled or not
      
      For example:
      
      	snd_hda_intel enabled=0
      	fixup enabled=1
      	driver enabled=0
      
      Enable a module:
      
      	$echo "set enabled=1 <module_name>" > dynamic_printk/modules
      
      Disable a module:
      
      	$echo "set enabled=0 <module_name>" > dynamic_printk/modules
      
      Enable all modules:
      
      	$echo "set enabled=1 all" > dynamic_printk/modules
      
      Disable all modules:
      
      	$echo "set enabled=0 all" > dynamic_printk/modules
      
      Finally, passing "dynamic_printk" at the command line enables
      debugging for all modules. This mode can be turned off via the above
      disable command.
      
      [gkh: minor cleanups and tweaks to make the build work quietly]
      Signed-off-by: NJason Baron <jbaron@redhat.com>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
      
      346e15be
  18. 04 10月, 2008 1 次提交
  19. 27 7月, 2008 2 次提交
    • J
      lib: generic show_mem() · 454c63b0
      Johannes Weiner 提交于
      This implements a platform-independent version of show_mem().
      Signed-off-by: NJohannes Weiner <hannes@saeurebad.de>
      Cc: Richard Henderson <rth@twiddle.net>
      Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
      Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
      Cc: Bryan Wu <cooloney@kernel.org>
      Cc: Chris Zankel <chris@zankel.net>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Jeff Dike <jdike@addtoit.com>
      Cc: David S. Miller <davem@davemloft.net>
      Cc: Paul Mundt <lethal@linux-sh.org>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: David Howells <dhowells@redhat.com>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Cc: Greg Ungerer <gerg@uclinux.org>
      Cc: Geert Uytterhoeven <geert@linux-m68k.org>
      Cc: Roman Zippel <zippel@linux-m68k.org>
      Cc: Hirokazu Takata <takata@linux-m32r.org>
      Cc: Mikael Starvik <starvik@axis.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      454c63b0
    • R
      task_current_syscall · bbc69863
      Roland McGrath 提交于
      This adds the new function task_current_syscall() on machines where the
      asm/syscall.h interface is supported (CONFIG_HAVE_ARCH_TRACEHOOK).  It's
      exported for modules to use in the future.  This function safely samples
      the state of a blocked thread to collect what system call it is blocked
      in, and the six system call argument registers.
      Signed-off-by: NRoland McGrath <roland@redhat.com>
      Cc: Oleg Nesterov <oleg@tv-sign.ru>
      Reviewed-by: NIngo Molnar <mingo@elte.hu>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      bbc69863
  20. 25 7月, 2008 1 次提交
  21. 17 7月, 2008 2 次提交
    • I
      ftrace: do not trace library functions · 2464a609
      Ingo Molnar 提交于
      make function tracing more robust: do not trace library functions.
      
      We've already got a sizable list of exceptions:
      
       ifdef CONFIG_FTRACE
       # Do not profile string.o, since it may be used in early boot or vdso
       CFLAGS_REMOVE_string.o = -pg
       # Also do not profile any debug utilities
       CFLAGS_REMOVE_spinlock_debug.o = -pg
       CFLAGS_REMOVE_list_debug.o = -pg
       CFLAGS_REMOVE_debugobjects.o = -pg
       CFLAGS_REMOVE_find_next_bit.o = -pg
       CFLAGS_REMOVE_cpumask.o = -pg
       CFLAGS_REMOVE_bitmap.o = -pg
       endif
      
      ... and the pattern has been that random library functionality showed
      up in ftrace's critical path (outside of its recursion check), causing
      hard to debug lockups.
      
      So be a bit defensive about it and exclude all lib/*.o functions by
      default. It's not that they are overly interesting for tracing purposes
      anyway. Specific ones can still be traced, in an opt-in manner.
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      2464a609
    • I
      ftrace: fix lockup with MAXSMP · 9fa11137
      Ingo Molnar 提交于
      MAXSMP brings in lots of use of various bitops in smp_processor_id()
      and friends - causing ftrace to lock up during bootup:
      
        calling  anon_inode_init+0x0/0x130
        initcall anon_inode_init+0x0/0x130 returned 0 after 0 msecs
        calling  acpi_event_init+0x0/0x57
        [ hard hang ]
      
      So exclude the bitops facilities from tracing.
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      9fa11137
  22. 12 7月, 2008 1 次提交
  23. 24 5月, 2008 3 次提交
  24. 30 4月, 2008 1 次提交
    • T
      infrastructure to debug (dynamic) objects · 3ac7fe5a
      Thomas Gleixner 提交于
      We can see an ever repeating problem pattern with objects of any kind in the
      kernel:
      
      1) freeing of active objects
      2) reinitialization of active objects
      
      Both problems can be hard to debug because the crash happens at a point where
      we have no chance to decode the root cause anymore.  One problem spot are
      kernel timers, where the detection of the problem often happens in interrupt
      context and usually causes the machine to panic.
      
      While working on a timer related bug report I had to hack specialized code
      into the timer subsystem to get a reasonable hint for the root cause.  This
      debug hack was fine for temporary use, but far from a mergeable solution due
      to the intrusiveness into the timer code.
      
      The code further lacked the ability to detect and report the root cause
      instantly and keep the system operational.
      
      Keeping the system operational is important to get hold of the debug
      information without special debugging aids like serial consoles and special
      knowledge of the bug reporter.
      
      The problems described above are not restricted to timers, but timers tend to
      expose it usually in a full system crash.  Other objects are less explosive,
      but the symptoms caused by such mistakes can be even harder to debug.
      
      Instead of creating specialized debugging code for the timer subsystem a
      generic infrastructure is created which allows developers to verify their code
      and provides an easy to enable debug facility for users in case of trouble.
      
      The debugobjects core code keeps track of operations on static and dynamic
      objects by inserting them into a hashed list and sanity checking them on
      object operations and provides additional checks whenever kernel memory is
      freed.
      
      The tracked object operations are:
      - initializing an object
      - adding an object to a subsystem list
      - deleting an object from a subsystem list
      
      Each operation is sanity checked before the operation is executed and the
      subsystem specific code can provide a fixup function which allows to prevent
      the damage of the operation.  When the sanity check triggers a warning message
      and a stack trace is printed.
      
      The list of operations can be extended if the need arises.  For now it's
      limited to the requirements of the first user (timers).
      
      The core code enqueues the objects into hash buckets.  The hash index is
      generated from the address of the object to simplify the lookup for the check
      on kfree/vfree.  Each bucket has it's own spinlock to avoid contention on a
      global lock.
      
      The debug code can be compiled in without being active.  The runtime overhead
      is minimal and could be optimized by asm alternatives.  A kernel command line
      option enables the debugging code.
      
      Thanks to Ingo Molnar for review, suggestions and cleanup patches.
      Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      Cc: Greg KH <greg@kroah.com>
      Cc: Randy Dunlap <randy.dunlap@oracle.com>
      Cc: Kay Sievers <kay.sievers@vrfy.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      3ac7fe5a
  25. 29 4月, 2008 1 次提交
  26. 27 4月, 2008 1 次提交
    • A
      x86: generic versions of find_first_(zero_)bit, convert i386 · 77b9bd9c
      Alexander van Heukelum 提交于
      Generic versions of __find_first_bit and __find_first_zero_bit
      are introduced as simplified versions of __find_next_bit and
      __find_next_zero_bit. Their compilation and use are guarded by
      a new config variable GENERIC_FIND_FIRST_BIT.
      
      The generic versions of find_first_bit and find_first_zero_bit
      are implemented in terms of the newly introduced __find_first_bit
      and __find_first_zero_bit.
      
      This patch does not remove the i386-specific implementation,
      but it does switch i386 to use the generic functions by setting
      GENERIC_FIND_FIRST_BIT=y for X86_32.
      Signed-off-by: NAlexander van Heukelum <heukelum@fastmail.fm>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      77b9bd9c
  27. 17 4月, 2008 1 次提交
  28. 29 3月, 2008 1 次提交
  29. 14 2月, 2008 1 次提交
  30. 09 2月, 2008 1 次提交
  31. 06 2月, 2008 1 次提交
  32. 29 1月, 2008 1 次提交
  33. 28 1月, 2008 1 次提交
  34. 15 11月, 2007 1 次提交
  35. 20 10月, 2007 1 次提交
    • P
      Fix cpusets update_cpumask · 8707d8b8
      Paul Menage 提交于
      Cause writes to cpuset "cpus" file to update cpus_allowed for member tasks:
      
      - collect batches of tasks under tasklist_lock and then call
        set_cpus_allowed() on them outside the lock (since this can sleep).
      
      - add a simple generic priority heap type to allow efficient collection
        of batches of tasks to be processed without duplicating or missing any
        tasks in subsequent batches.
      
      - make "cpus" file update a no-op if the mask hasn't changed
      
      - fix race between update_cpumask() and sched_setaffinity() by making
        sched_setaffinity() post-check that it's not running on any cpus outside
        cpuset_cpus_allowed().
      
      [akpm@linux-foundation.org: coding-style fixes]
      Signed-off-by: NPaul Menage <menage@google.com>
      Cc: Paul Jackson <pj@sgi.com>
      Cc: David Rientjes <rientjes@google.com>
      Cc: Nick Piggin <nickpiggin@yahoo.com.au>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Balbir Singh <balbir@in.ibm.com>
      Cc: Cedric Le Goater <clg@fr.ibm.com>
      Cc: "Eric W. Biederman" <ebiederm@xmission.com>
      Cc: Serge Hallyn <serue@us.ibm.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      8707d8b8
  36. 17 10月, 2007 1 次提交