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2011-05-19list: remove prefetching from regular list iteratorsLinus Torvalds1-15/+11
This is removes the use of software prefetching from the regular list iterators. We don't want it. If you do want to prefetch in some iterator of yours, go right ahead. Just don't expect the iterator to do it, since normally the downsides are bigger than the upsides. It also replaces <linux/prefetch.h> with <linux/const.h>, because the use of LIST_POISON ends up needing it. <linux/poison.h> is sadly not self-contained, and including prefetch.h just happened to hide that. Suggested by David Miller (networking has a lot of regular lists that are often empty or a single entry, and prefetching is not going to do anything but add useless instructions). Acked-by: Ingo Molnar <mingo@elte.hu> Acked-by: David S. Miller <davem@davemloft.net> Cc: linux-arch@vger.kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-19hlist: remove software prefetching in hlist iteratorsLinus Torvalds1-5/+4
They not only increase the code footprint, they actually make things slower rather than faster. On internationally acclaimed benchmarks ("make -j16" on an already fully built kernel source tree) the hlist prefetching slows down the build by up to 1%. (Almost all of it comes from hlist_for_each_entry_rcu() as used by avc_has_perm_noaudit(), which is very hot due to all the pathname lookups to see if there is anything to do). The cause seems to be two-fold: - on at least some Intel cores, prefetch(NULL) ends up with some microarchitectural stall due to the TLB miss that it incurs. The hlist case triggers this very commonly, since the NULL pointer is the last entry in the list. - the prefetch appears to cause more D$ activity, probably because it prefetches hash list entries that are never actually used (because we ended the search early due to a hit). Regardless, the numbers clearly say that the implicit prefetching is simply a bad idea. If some _particular_ user of the hlist iterators wants to prefetch the next list entry, they can do so themselves explicitly, rather than depend on all list iterators doing so implicitly. Acked-by: Ingo Molnar <mingo@elte.hu> Acked-by: David S. Miller <davem@davemloft.net> Cc: linux-arch@vger.kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-02-18Expand CONFIG_DEBUG_LIST to several other list operationsLinus Torvalds1-3/+9
When list debugging is enabled, we aim to readably show list corruption errors, and the basic list_add/list_del operations end up having extra debugging code in them to do some basic validation of the list entries. However, "list_del_init()" and "list_move[_tail]()" ended up avoiding the debug code due to how they were written. This fixes that. So the _next_ time we have list_move() problems with stale list entries, we'll hopefully have an easier time finding them.. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-25list.h: new helper - hlist_add_fake()Al Viro1-0/+6
Make node look as if it was on hlist, with hlist_del() working correctly. Usable without any locking... Convert a couple of places where we want to do that to inode->i_hash. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-07Drop a couple of unnecessary asm/system.h inclusionsDavid Howells1-1/+0
Drop inclusions of asm/system.h from linux/hardirq.h and linux/list.h as they're no longer required and prevent the M68K arch's IRQ flag handling macros from being made into inlined functions due to circular dependencies. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Greg Ungerer <gerg@uclinux.org> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
2010-07-06Merge branch 'master' into for-linusChris Metcalf1-0/+15
2010-07-06Move list types from <linux/list.h> to <linux/types.h>.Chris Metcalf1-12/+1
This allows a list_head (or hlist_head, etc.) to be used from places that used to be impractical, in particular <asm/processor.h>, which used to cause include file recursion: <linux/list.h> includes <linux/prefetch.h>, which always includes <asm/processor.h> for the prefetch macros, as well as <asm/system.h>, which often includes <asm/processor.h> directly or indirectly. This avoids a lot of painful workaround hackery on the tile architecture, where we use a list_head in the thread_struct to chain together tasks that are activated on a particular hardwall. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com> Reviewed-by: Matthew Wilcox <willy@linux.intel.com>
2010-06-29fs: fix superblock iteration racenpiggin@suse.de1-0/+15
list_for_each_entry_safe is not suitable to protect against concurrent modification of the list. 6754af6 introduced a race in sb walking. list_for_each_entry can use the trick of pinning the current entry in the list before we drop and retake the lock because it subsequently follows cur->next. However list_for_each_entry_safe saves n=cur->next for following before entering the loop body, so when the lock is dropped, n may be deleted. Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Christoph Hellwig <hch@infradead.org> Cc: John Stultz <johnstul@us.ibm.com> Cc: Frank Mayhar <fmayhar@google.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-06lib: fix first line of kernel-doc for a few functionsBen Hutchings1-3/+3
The function name must be followed by a space, hypen, space, and a short description. Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-01-16list: Introduce list_rotate_left()Frederic Weisbecker1-0/+14
Bring a new list_rotate_left() helper that rotates a list to the left. This is useful for codes that need to round roubin elements which queue priority increases from tail to head. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
2008-09-01debugobjects: fix lockdep warningVegard Nossum1-0/+13
Daniel J. Blueman reported: > ======================================================= > [ INFO: possible circular locking dependency detected ] > 2.6.27-rc4-224c #1 > ------------------------------------------------------- > hald/4680 is trying to acquire lock: > (&n->list_lock){++..}, at: [<ffffffff802bfa26>] add_partial+0x26/0x80 > > but task is already holding lock: > (&obj_hash[i].lock){++..}, at: [<ffffffff8041cfdc>] > debug_object_free+0x5c/0x120 We fix it by moving the actual freeing to outside the lock (the lock now only protects the list). The pool lock is also promoted to irq-safe (suggested by Dan). It's necessary because free_pool is now called outside the irq disabled region. So we need to protect against an interrupt handler which calls debug_object_init(). [tglx@linutronix.de: added hlist_move_list helper to avoid looping through the list twice] Reported-by: Daniel J Blueman <daniel.blueman@gmail.com> Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-08-08list.h: fix fatal kernel-doc errorRandy Dunlap1-2/+2
Fix fatal multi-line kernel-doc error in list.h: function short description must be on one line. Error(linux-2.6.27-rc2-git3//include/linux/list.h:318): duplicate section name 'Description' Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-07list.h: add list_cut_position()Luis R. Rodriguez1-0/+40
This adds list_cut_position() which lets you cut a list into two lists given a pivot in the list. Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-08-07list.h: Add list_splice_tail() and list_splice_tail_init()Luis R. Rodriguez1-9/+38
If you are using linked lists for queues list_splice() will not do what you would expect even if you use the elements passed reversed. We need to handle these differently. We add list_splice_tail() and list_splice_tail_init(). Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
2008-07-25lists: remove a redundant conditional definition of list_add()Robert P. J. Day1-4/+0
Remove the conditional surrounding the definition of list_add() from list.h since, if you define CONFIG_DEBUG_LIST, the definition you will subsequently pick up from lib/list_debug.c will be absolutely identical, at which point you can remove that redundant definition from list_debug.c as well. Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca> Cc: Dave Jones <davej@codemonkey.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-19rcu: split list.h and move rcu-protected lists into rculist.hFranck Bui-Huu1-367/+0
Move rcu-protected lists from list.h into a new header file rculist.h. This is done because list are a very used primitive structure all over the kernel and it's currently impossible to include other header files in this list.h without creating some circular dependencies. For example, list.h implements rcu-protected list and uses rcu_dereference() without including rcupdate.h. It actually compiles because users of rcu_dereference() are macros. Others RCU functions could be used too but aren't probably because of this. Therefore this patch creates rculist.h which includes rcupdates without to many changes/troubles. Signed-off-by: Franck Bui-Huu <fbuihuu@gmail.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Josh Triplett <josh@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-04-30Remove "#ifdef __KERNEL__" checks from unexported headersRobert P. J. Day1-5/+0
Remove the "#ifdef __KERNEL__" tests from unexported header files in linux/include whose entire contents are wrapped in that preprocessor test. Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29lists: add "const" qualifier to first arg of list_splice() operationsRobert P. J. Day1-2/+3
Since neither the list_splice() nor __list_splice() routines modify their first argument, might as well declare them "const". [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28list.h: add list_is_singular()Masami Hiramatsu1-0/+9
Add list_is_singular() to check a list has just one entry. list_is_singular() is useful to check whether a list_head which have been temporarily allocated for listing objects can be released or not. Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: 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>
2008-04-21Fix RCU list iterator use of 'rcu_dereference()'Linus Torvalds1-33/+15
The RCU iterators used 'rcu_dereference()' on an already-fetched RCU pointer value, which defeats the whole point of the exercise. When we dereference a pointer protected by RCU, we need to make sure that we only fetch the value _once_, because if the compiler ends up re-loading it due to register pressure, the newly reloaded value could be different from the previously fetched one, and you get inconsistent results. Cleaned-up, fixed, and the pointless list_for_each_safe_rcu #define deleted by Paul Kenney. Acked-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-19kernel-api docbook: fix content problemsRandy Dunlap1-2/+1
Fix kernel-api docbook contents problems. docproc: linux-2.6.23-git13/include/asm-x86/unaligned_32.h: No such file or directory Warning(linux-2.6.23-git13//include/linux/list.h:482): bad line: of list entry Warning(linux-2.6.23-git13//mm/filemap.c:864): No description found for parameter 'ra' Warning(linux-2.6.23-git13//block/ll_rw_blk.c:3760): No description found for parameter 'req' Warning(linux-2.6.23-git13//include/linux/input.h:1077): No description found for parameter 'private' Warning(linux-2.6.23-git13//include/linux/input.h:1077): No description found for parameter 'cdev' Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Cc: Jens Axboe <jens.axboe@oracle.com> Cc: WU Fengguang <wfg@mail.ustc.edu.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-17shrink_dcache_sb speedupDenis V. Lunev1-0/+12
This patch makes shrink_dcache_sb consistent with dentry pruning policy. On the first pass we iterate over dentry unused list and prepare some dentries for removal. However, since the existing code moves evicted dentries to the beginning of the LRU it can happen that fresh dentries from other superblocks will be inserted *before* our dentries. This can result in significant slowdown of shrink_dcache_sb(). Moreover, for virtual filesystems like unionfs which can call dput() during dentries kill existing code results in O(n^2) complexity. We observed 2 minutes shrink_dcache_sb() with only 35000 dentries. To avoid this effects we propose to isolate sb dentries at the end of LRU list. Signed-off-by: Denis V. Lunev <den@openvz.org> Signed-off-by: Kirill Korotaev <dev@openvz.org> Signed-off-by: Andrey Mirkin <amirkin@openvz.org> Cc: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-10[NETNS]: Cleanup list walking in setup_net and cleanup_netPavel Emelyanov1-0/+14
I proposed introducing a list_for_each_entry_continue_reverse macro to be used in setup_net() when unrolling the failed ->init callback. Here is the macro and some more cleanup in the setup_net() itself to remove one variable from the stack :) The same thing is for the cleanup_net() - the existing list_for_each_entry_reverse() is used. Minor, but the code looks nicer. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2007-05-12include/linux: trivial repair whitespace damageDaniel Walker1-4/+4
Adding tabs where spaces currently are. Signed-off-by: Daniel Walker <dwalker@mvista.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08Introduce a handy list_first_entry macroPavel Emelianov1-0/+11
There are many places in the kernel where the construction like foo = list_entry(head->next, struct foo_struct, list); are used. The code might look more descriptive and neat if using the macro list_first_entry(head, type, member) \ list_entry((head)->next, type, member) Here is the macro itself and the examples of its usage in the generic code. If it will turn out to be useful, I can prepare the set of patches to inject in into arch-specific code, drivers, networking, etc. Signed-off-by: Pavel Emelianov <xemul@openvz.org> Signed-off-by: Kirill Korotaev <dev@openvz.org> Cc: Randy Dunlap <randy.dunlap@oracle.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Zach Brown <zach.brown@oracle.com> Cc: Davide Libenzi <davidel@xmailserver.org> Cc: John McCutchan <ttb@tentacle.dhs.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: john stultz <johnstul@us.ibm.com> Cc: Ram Pai <linuxram@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-11[PATCH] Numerous fixes to kernel-doc info in source files.Robert P. J. Day1-5/+6
A variety of (mostly) innocuous fixes to the embedded kernel-doc content in source files, including: * make multi-line initial descriptions single line * denote some function names, constants and structs as such * change erroneous opening '/*' to '/**' in a few places * reword some text for clarity Signed-off-by: Robert P. J. Day <rpjday@mindspring.com> Cc: "Randy.Dunlap" <rdunlap@xenotime.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-11[PATCH] add an RCU version of list splicingCorey Minyard1-0/+56
This patch is in support of the IPMI driver. I have tested this with the IPMI driver changes coming in the next patch. Add a list_splice_init_rcu() function to splice an RCU-protected list into another list. This takes the sync function as an argument, so one would do something like: INIT_LIST_HEAD(&list); list_splice_init_rcu(&source, &dest, synchronize_rcu); The idea being to keep the RCU API proliferation down to a dull roar. [akpm@osdl.org: build fix] Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Corey Minyard <minyard@acm.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-01-26[PATCH] fix various kernel-doc in header filesRobert P. J. Day1-5/+5
Fix a number of kernel-doc entries for header files in include/linux by making sure they begin with the appropriate '/**' notation and use @var notation. Signed-off-by: Robert P. J. Day <rpjday@mindspring.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2006-09-29[PATCH] Debug variants of linked list macrosDave Jones1-0/+15
Signed-off-by: Dave Jones <davej@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-14[PATCH] list_is_last utilityShailabh Nagar1-0/+11
Add another list utility function to check for last element in a list. Signed-off-by: Shailabh Nagar <nagar@watson.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-27[PATCH] add poison.h and patch primary usersRandy Dunlap1-8/+1
Localize poison values into one header file for better documentation and easier/quicker debugging and so that the same values won't be used for multiple purposes. Use these constants in core arch., mm, driver, and fs code. Signed-off-by: Randy Dunlap <rdunlap@xenotime.net> Acked-by: Matt Mackall <mpm@selenic.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Andi Kleen <ak@muc.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-25[PATCH] list.h doc: change "counter" to "cursor"Randy Dunlap1-26/+26
Use loop "cursor" instead of loop "counter" for list iterator descriptions. They are not counters, they are pointers or positions. Signed-off-by: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-25[PATCH] fix list.h kernel-docRandy Dunlap1-30/+52
kernel-doc: Put all short function descriptions on one line or if they are too long, omit the short description & add a Description: section for them. Change some list iterator descriptions to use "current" point instead of "existing" point. Signed-off-by: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23[PATCH] list: introduce list_replace() helperOleg Nesterov1-0/+23
list_replace() is similar to list_replace_rcu(), but unlike list_replace_rcu() it could be used when list_empty(old) == 1 doesn't use barriers Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-04-29[NET]: use hlist_unhashed()Akinobu Mita1-1/+1
Use hlist_unhashed() rather than accessing inside data structure. Signed-off-by: Akinobu Mita <mita@miraclelinux.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20[LIST]: Introduce list_for_each_entry_fromArnaldo Carvalho de Melo1-0/+11
For iterating over list of given type continuing from existing point. Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20[LIST]: Introduce list_for_each_entry_safe_fromArnaldo Carvalho de Melo1-0/+13
For iterate over list of given type from existing point safe against removal of list entry. Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-02-03[PATCH] list.h: don't evaluate macro args multiple timesZach Brown1-4/+10
I noticed that list.h init functions were evaluating macro arguments multiple times and thought it might be nice to protect the unsuspecting caller. Converting the macros to inline functions seems to reduce code size, too. A i386 defconfig build with gcc 3.3.3 from fc4: text data bss dec hex filename 3573148 565664 188828 4327640 4208d8 vmlinux.before 3572177 565664 188828 4326669 42050d vmlinux add/remove: 0/0 grow/shrink: 11/144 up/down: 88/-1016 (-928) There was no difference in checkstack output. Signed-off-by: Zach Brown <zach.brown@oracle.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-10[PATCH] Add list_for_each_entry_safe_reverse()David Howells1-0/+14
Add list_for_each_entry_safe_reverse() to linux/list.h This is needed by unmerged cachefs and be an as-yet-unreviewed device_shutdown() fix. Signed-off-by: David Howells <dhowells@redhat.com> Cc: Patrick Mochel <mochel@digitalimplant.org> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-12-12[PATCH] add hlist_replace_rcu()Ingo Molnar1-1/+25
Add list_replace_rcu: replace old entry by new one. Signed-off-by: Paul E. McKenney <paulmck@us.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-07[PATCH] Remove hlist_for_each_rcu() API, convert existing use to hlist_for_each_entry_rcuPaul E. McKenney1-9/+4
Remove the hlist_for_each_rcu() API, which is used only in one place, and is trivially converted to hlist_for_each_entry_rcu(), making the code shorter and more readable. Any out-of-tree uses may be similarly converted. Signed-off-by: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-17[PATCH] list: add missing rcu_dereference on first elementHerbert Xu1-17/+22
It seems that all the list_*_rcu primitives are missing a memory barrier on the very first dereference. For example, #define list_for_each_rcu(pos, head) \ for (pos = (head)->next; prefetch(pos->next), pos != (head); \ pos = rcu_dereference(pos->next)) It will go something like: pos = (head)->next prefetch(pos->next) pos != (head) do stuff We're missing a barrier here. pos = rcu_dereference(pos->next) fetch pos->next barrier given by rcu_dereference(pos->next) store pos Without the missing barrier, the pos->next value may turn out to be stale. In fact, if "do stuff" were also dereferencing pos and relying on list_for_each_rcu to provide the barrier then it may also break. So here is a patch to make sure that we have a barrier for the first element in the list. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Acked-by: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-08-29[LIST]: Add docbook header comments for hlist_add_{before,after}_rcu()Paul E. McKenney1-0/+30
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-29[IPV4]: Prepare FIB core for RCU.Robert Olsson1-0/+21
* RCU versions of hlist_***_rcu * fib_alias partial rcu port just whats needed now. Signed-off-by: Robert Olsson <Robert.Olsson@data.slu.se> Signed-off-by: Stephen Hemminger <shemminger@osdl.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-08-29[CCID3]: Separate most of the packet history codeArnaldo Carvalho de Melo1-1/+2
This also changes the list_for_each_entry_safe_continue behaviour to match its kerneldoc comment, that is, to start after the pos passed. Also adds several helper functions from previously open coded fragments, making the code more clear. Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
2005-08-29[LIST]: Introduce list_for_each_entry_safe_continueArnaldo Carvalho de Melo1-0/+13
Used in the dccp CCID3 code, that is going to be submitted RSN. Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-06-25[PATCH] RCU: clean up a few remaining synchronize_kernel() callsPaul E. McKenney1-1/+1
2.6.12-rc6-mm1 has a few remaining synchronize_kernel()s, some (but not all) in comments. This patch changes these synchronize_kernel() calls (and comments) to synchronize_rcu() or synchronize_sched() as follows: - arch/x86_64/kernel/mce.c mce_read(): change to synchronize_sched() to handle races with machine-check exceptions (synchronize_rcu() would not cut it given RCU implementations intended for hardcore realtime use. - drivers/input/serio/i8042.c i8042_stop(): change to synchronize_sched() to handle races with i8042_interrupt() interrupt handler. Again, synchronize_rcu() would not cut it given RCU implementations intended for hardcore realtime use. - include/*/kdebug.h comments: change to synchronize_sched() to handle races with NMIs. As before, synchronize_rcu() would not cut it... - include/linux/list.h comment: change to synchronize_rcu(), since this comment is for list_del_rcu(). - security/keys/key.c unregister_key_type(): change to synchronize_rcu(), since this is interacting with RCU read side. - security/keys/process_keys.c install_session_keyring(): change to synchronize_rcu(), since this is interacting with RCU read side. Signed-off-by: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-04-16[PATCH] Fix comment in list.h that refers to nonexistent APIPaul E. McKenney1-1/+1
The hlist_for_each_entry_rcu() comment block refers to a nonexistent hlist_add_rcu() API, needs to change to hlist_add_head_rcu(). Signed-off-by: Paul E. McKenney <paulmck@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-04-16Linux-2.6.12-rc2Linus Torvalds1-0/+707
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!