- 24 6月, 2009 1 次提交
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由 Paul E. McKenney 提交于
Remove Classic RCU, given that the combination of Tree RCU and the proposed Bloatwatch RCU do everything that Classic RCU can with fewer bugs. Tree RCU has been default in x86 builds for almost six months, and seems to be quite reliable, so there does not seem to be much justification for keeping the Classic RCU code and config complexity around anymore. Signed-off-by: NPaul E. McKenney <paulmck@linux.ibm.com> Cc: akpm@linux-foundation.org Cc: niv@us.ibm.com Cc: dvhltc@us.ibm.com Cc: dipankar@in.ibm.com Cc: dhowells@redhat.com Cc: lethal@linux-sh.org Cc: kernel@wantstofly.org Signed-off-by: NIngo Molnar <mingo@elte.hu>
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- 19 6月, 2009 1 次提交
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由 Peter Oberparleiter 提交于
Call constructors (gcc-generated initcall-like functions) during kernel start and module load. Constructors are e.g. used for gcov data initialization. Disable constructor support for usermode Linux to prevent conflicts with host glibc. Signed-off-by: NPeter Oberparleiter <oberpar@linux.vnet.ibm.com> Acked-by: NRusty Russell <rusty@rustcorp.com.au> Acked-by: NWANG Cong <xiyou.wangcong@gmail.com> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: Jeff Dike <jdike@addtoit.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Huang Ying <ying.huang@intel.com> Cc: Li Wei <W.Li@Sun.COM> Cc: Michael Ellerman <michaele@au1.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Heiko Carstens <heicars2@linux.vnet.ibm.com> Cc: Martin Schwidefsky <mschwid2@linux.vnet.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 16 6月, 2009 1 次提交
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由 Kay Sievers 提交于
All recent distros depend on the non-deprecated sysfs layout, so change the default value of the option to reflect that. Signed-off-by: NKay Sievers <kay.sievers@vrfy.org> Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
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- 13 6月, 2009 1 次提交
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由 Mike Frysinger 提交于
Help out arch porters who want to support perf counters by listing some basic requirements. Signed-off-by: NMike Frysinger <vapier@gentoo.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> LKML-Reference: <1244827063-24046-1-git-send-email-vapier@gentoo.org> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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- 12 6月, 2009 1 次提交
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由 Eric Paris 提交于
Reimplement inotify_user using fsnotify. This should be feature for feature exactly the same as the original inotify_user. This does not make any changes to the in kernel inotify feature used by audit. Those patches (and the eventual removal of in kernel inotify) will come after the new inotify_user proves to be working correctly. Signed-off-by: NEric Paris <eparis@redhat.com> Acked-by: NAl Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de>
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- 11 6月, 2009 1 次提交
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由 Ingo Molnar 提交于
Perfcounters were enabled by default to help testing - but now that we are submitting it upstream, make it default-disabled. Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> LKML-Reference: <new-submission> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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- 10 6月, 2009 1 次提交
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由 Randy Dunlap 提交于
The STRIP_ASM_SYMS kconfig symbol mucks up the embedded menu because STRIP_ASM_SYMS is in the middle of the embedded menu items but it does not depend on EMBEDDED. Move it to beyond the end of the embedded menu so that the menu is presented correctly. Or if STRIP_ASM_SYMS should depend on EMBEDDED, that can also be fixed. Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NSam Ravnborg <sam@ravnborg.org>
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- 11 4月, 2009 1 次提交
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由 David Howells 提交于
Make it possible for the linker to discard local symbols from vmlinux as they cause vmlinux to balloon when CONFIG_KALLSYMS=y and they cause dump_stack() and get_wchan() to produce useless information under some circumstances. With this we add a config option (CONFIG_STRIP_ASM_SYMS) that will cause the build to supply -X to the linker to tell it to strip temporary local symbols. This doesn't seem to cause gdb any problems. Signed-off-by: NDavid Howells <dhowells@redhat.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NSam Ravnborg <sam@ravnborg.org>
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- 07 4月, 2009 3 次提交
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由 Serge E. Hallyn 提交于
Largely inspired from ipc/ipc_sysctl.c. This patch isolates the mqueue sysctl stuff in its own file. [akpm@linux-foundation.org: build fix] Signed-off-by: NCedric Le Goater <clg@fr.ibm.com> Signed-off-by: NNadia Derbey <Nadia.Derbey@bull.net> Signed-off-by: NSerge E. Hallyn <serue@us.ibm.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Serge E. Hallyn 提交于
Move mqueue vfsmount plus a few tunables into the ipc_namespace struct. The CONFIG_IPC_NS boolean and the ipc_namespace struct will serve both the posix message queue namespaces and the SYSV ipc namespaces. The sysctl code will be fixed separately in patch 3. After just this patch, making a change to posix mqueue tunables always changes the values in the initial ipc namespace. Signed-off-by: NCedric Le Goater <clg@fr.ibm.com> Signed-off-by: NSerge E. Hallyn <serue@us.ibm.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 David Howells 提交于
Make CONFIG_SLOW_WORK an automatic rather than manual config option so that people configuring their kernels don't have to make the choice. It can be selected automatically by those things that require it (such as FS-Cache). Signed-off-by: NDavid Howells <dhowells@redhat.com> Acked-by: NJeff Garzik <jgarzik@redhat.com> Acked-by: NKyle McMartin <kyle@mcmartin.ca> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 06 4月, 2009 1 次提交
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由 Peter Zijlstra 提交于
Impact: new perfcounters feature Enable usage of tracepoints as perf counter events. tracepoint event ids can be found in /debug/tracing/event/*/*/id and (for now) are represented as -65536+id in the type field. Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Cc: Steven Rostedt <rostedt@goodmis.org> Orig-LKML-Reference: <20090319194233.744044174@chello.nl> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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- 04 4月, 2009 1 次提交
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由 Paul E. McKenney 提交于
Impact: switch default config from CLASSIC_RCU to TREE_RCU Given that I have not gotten any complaints or bug reports on treercu recently, this patch makes it be the default. There are a number of other defconfig files that explicitly call out CLASSIC_RCU, but which have comment headers saying not to edit them. Probably holdovers from one of the flavors of "make config", but... Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: akpm@linux-foundation.org Cc: dipankar@in.ibm.com Cc: niv@us.ibm.com Cc: manfred@colorfullife.com Cc: peterz@infradead.org LKML-Reference: <20090403040625.GA9473@linux.vnet.ibm.com> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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- 03 4月, 2009 3 次提交
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由 David Howells 提交于
Create a dynamically sized pool of threads for doing very slow work items, such as invoking mkdir() or rmdir() - things that may take a long time and may sleep, holding mutexes/semaphores and hogging a thread, and are thus unsuitable for workqueues. The number of threads is always at least a settable minimum, but more are started when there's more work to do, up to a limit. Because of the nature of the load, it's not suitable for a 1-thread-per-CPU type pool. A system with one CPU may well want several threads. This is used by FS-Cache to do slow caching operations in the background, such as looking up, creating or deleting cache objects. Signed-off-by: NDavid Howells <dhowells@redhat.com> Acked-by: NSerge Hallyn <serue@us.ibm.com> Acked-by: NSteve Dickson <steved@redhat.com> Acked-by: NTrond Myklebust <Trond.Myklebust@netapp.com> Acked-by: NAl Viro <viro@zeniv.linux.org.uk> Tested-by: NDaire Byrne <Daire.Byrne@framestore.com>
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由 Paul Menage 提交于
Allow cpusets to be configured/built on non-SMP systems Currently it's impossible to build cpusets under UML on x86-64, since cpusets depends on SMP and x86-64 UML doesn't support SMP. There's code in cpusets that doesn't depend on SMP. This patch surrounds the minimum amount of cpusets code with #ifdef CONFIG_SMP in order to allow cpusets to build/run on UP systems (for testing purposes under UML). Reviewed-by: NLi Zefan <lizf@cn.fujitsu.com> Signed-off-by: NPaul Menage <menage@google.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 KAMEZAWA Hiroyuki 提交于
It's pointed out that swap_cgroup's message at swapon() is nonsense. Because * It can be calculated very easily if all necessary information is written in Kconfig. * It's not necessary to annoying people at every swapon(). In other view, now, memory usage per swp_entry is reduced to 2bytes from 8bytes(64bit) and I think it's reasonably small. Reported-by: NHugh Dickins <hugh@veritas.com> Signed-off-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>
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- 30 3月, 2009 2 次提交
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cgroup documentation was moved to Documentation/cgroups/. There are some places that still refer to Documentation/controllers/, Documentation/cgroups.txt and Documentation/cpusets.txt. Fix those. Signed-off-by: NThadeu Lima de Souza Cascardo <cascardo@holoscopio.com> Reviewed-by: NLi Zefan <lizf@cn.fujitsu.com> Acked-by: NPaul Menage <menage@google.com> Signed-off-by: NJiri Kosina <jkosina@suse.cz>
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由 Matt LaPlante 提交于
Signed-off-by: NMatt LaPlante <kernel1@cyberdogtech.com> Acked-by: NRandy Dunlap <randy.dunlap@oracle.com> Signed-off-by: NJiri Kosina <jkosina@suse.cz>
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- 11 3月, 2009 1 次提交
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由 Randy Dunlap 提交于
The COMPAT_BRK kconfig symbol does not depend on EMBEDDED, but it is in the midst of the EMBEDDED menu symbols, so it mucks up the EMBEDDED menu. Fix by moving it to just after all of the EMBEDDED menu symbols. Also, ANON_INODES has a similar problem, so move it to just above the EMBEDDED menu items since it is used in the EMBEDDED menu. Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 03 3月, 2009 2 次提交
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由 Linus Torvalds 提交于
This reverts commit 155b25bc, which was totally wrong - the "embedded" options still exists (very much so) even on non-embedded platforms. It's just that we don't bother with actually asking about them when we're not embedded, we just take their default values (which is usually 'y' - the options add features that may not be worth it in a constrained environment). Noticed-by: NAndrew Morton <akpm@linux-foundation.org> Cc: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Randy Dunlap 提交于
The COMPAT_BRK kconfig symbol does not depend on EMBEDDED, but it is in the midst of the EMBEDDED menu symbols, so it mucks up the EMBEDDED menu. Fix by moving it to just after all of the EMBEDDED menu symbols. Also, surround all of the EMBEDDED symbols with "if EMBEDDED"/"endif" so that this EMBEDDED block is clearer. Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 21 2月, 2009 1 次提交
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由 Frederic Weisbecker 提交于
Sometimes it happens that KConfig dependencies are not handled like in the following scenario: - config A bool - config B bool depends on A - config C bool select B If one selects C, then it will select B without checking its dependency to A, if A hasn't been selected elsewhere, it will result in a build failure. This is what happens on the following build error: kernel/built-in.o: In function `marker_update_probe_range': (.text+0x52f64): undefined reference to `tracepoint_probe_register_noupdate' kernel/built-in.o: In function `marker_update_probe_range': (.text+0x52f74): undefined reference to `tracepoint_probe_unregister_noupdate' kernel/built-in.o: In function `marker_update_probe_range': (.text+0x52fb9): undefined reference to `tracepoint_probe_unregister_noupdate' kernel/built-in.o: In function `marker_update_probes': marker.c:(.text+0x530ba): undefined reference to `tracepoint_probe_update_all' CONFIG_KVM_TRACE will select CONFIG_MARKER, but the latter depends on CONFIG_TRACEPOINTS which will not be selected. Reported-by: NIngo Molnar <mingo@elte.hu> Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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- 27 1月, 2009 1 次提交
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由 Matt Helsley 提交于
Make NET_NS available underneath the generic Namespaces config option since all of the other namespace options are there. Signed-off-by: NMatt Helsley <matthltc@us.ibm.com> Acked-by: NSerge Hallyn <serue@us.ibm.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 16 1月, 2009 4 次提交
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由 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>
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由 Li Zefan 提交于
Move Documentation/cpusets.txt and Documentation/controllers/* to Documentation/cgroups/ Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com> Acked-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: NBalbir Singh <balbir@linux.vnet.ibm.com> Acked-by: NPaul Menage <menage@google.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Li Zefan 提交于
- move CONFIG_PROC_PID_CPUSET into cgroup menu - move MM_OWNER to the bottom for better menu indent - fix typos - use tabs not spaces Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com> Acked-by: NPaul Menage <menage@google.com> Acked-by: NBalbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Mike Travis 提交于
Move RCU Kconfig options from top-level menu to an "RCU Subsystem" menu under the "General Setup" menu. Signed-off-by: NMike Travis <travis@sgi.com> Tested-by: N"Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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- 15 1月, 2009 1 次提交
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由 Sam Ravnborg 提交于
This reverts commit ad7a953c. And commit: ("allow stripping of generated symbols under CONFIG_KALLSYMS_ALL") 9bb48247 These stripping patches has caused a set of issues: 1) People have reported compatibility issues with binutils due to lack of support for `--strip-unneeded-symbols' with objcopy 2.15.92.0.2 Reported by: Wenji 2) ccache and distcc no longer works as expeced Reported by: Ted, Roland, + others 3) The installed modules increased a lot in size Reported by: Ted, Davej + others Reported-by: NWenji Huang <wenji.huang@oracle.com> Reported-by: N"Theodore Ts'o" <tytso@mit.edu> Reported-by: NDave Jones <davej@redhat.com> Reported-by: NRoland McGrath <roland@redhat.com> Signed-off-by: NSam Ravnborg <sam@ravnborg.org>
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- 09 1月, 2009 3 次提交
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由 KAMEZAWA Hiroyuki 提交于
Config and control variable for mem+swap controller. This patch adds CONFIG_CGROUP_MEM_RES_CTLR_SWAP (memory resource controller swap extension.) For accounting swap, it's obvious that we have to use additional memory to remember "who uses swap". This adds more overhead. So, it's better to offer "choice" to users. This patch adds 2 choices. This patch adds 2 parameters to enable swap extension or not. - CONFIG - boot option Reviewed-by: NDaisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Li Zefan 提交于
s/contoller/controller/ Signed-of-by: NLi Zefan <lizf@cn.fujitsu.com> Cc: Paul Menage <menage@google.com> Acked-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Pavel Emelyanov <xemul@openvz.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 KAMEZAWA Hiroyuki 提交于
Making CGROUP related configs be a sub-menu. This patch make CGROUP related configs be a sub-menu and makes 1st level configs of "General Setup" shorter. including following additional changes - add help comment about CGROUPS and GROUP_SCHED. - moved MM_OWNER config to the bottom. (for good indent in menuconfig) Signed-off-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: NDaisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Paul Menage <menage@google.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 07 1月, 2009 2 次提交
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由 Matt Mackall 提交于
tiny-shmem shares most of its 130 lines of code with shmem and tends to break when particular bits of shmem get modified. Unifying saves code and makes keeping these two in sync much easier. before: 14367 392 24 14783 39bf mm/shmem.o 396 72 8 476 1dc mm/tiny-shmem.o after: 14367 392 24 14783 39bf mm/shmem.o 412 72 8 492 1ec mm/shmem.o tiny Signed-off-by: NMatt Mackall <mpm@selenic.com> Acked-by: NHugh Dickins <hugh@veritas.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Kay Sievers 提交于
This should make the help text of SYSFS_DEPRECATED more clear, that this is _not_ about (what some people think it is) suppressing a few symlinks and variables, but a different sysfs _layout_ with new features. Signed-off-by: NKay Sievers <kay.sievers@vrfy.org> Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
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- 05 1月, 2009 3 次提交
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由 H. Peter Anvin 提交于
Impact: Bug fix (we should not show this menu on irrelevant architectures) Make the config machinery to drive the gzip/bzip2/lzma selection dependent on the architecture advertising HAVE_KERNEL_* so that we don't display this for architectures where it doesn't matter. Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
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由 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>
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由 Johannes Berg 提交于
Now that nothing depends on it any more, remove CONFIG_KMOD. Signed-off-by: NJohannes Berg <johannes@sipsolutions.net> Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
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- 25 12月, 2008 1 次提交
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由 Ingo Molnar 提交于
Impact: build fix Some old architectures still do not use kernel/Kconfig.preempt, so the moving of the RCU options there broke their build: In file included from /home/mingo/tip/include/linux/sem.h:81, from /home/mingo/tip/include/linux/sched.h:69, from /home/mingo/tip/arch/alpha/kernel/asm-offsets.c:9: /home/mingo/tip/include/linux/rcupdate.h:62:2: error: #error "Unknown RCU implementation specified to kernel configuration" Move these options back to init/Kconfig, which every architecture includes. Signed-off-by: NIngo Molnar <mingo@elte.hu>
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- 20 12月, 2008 1 次提交
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由 Jan Beulich 提交于
Building upon parts of the module stripping patch, this patch introduces similar stripping for vmlinux when CONFIG_KALLSYMS_ALL=y. Using CONFIG_KALLSYMS_STRIP_GENERATED reduces the overhead of CONFIG_KALLSYMS_ALL from 245k/310k to 65k/80k for the (i386/x86-64) kernels I tested with. The patch also does away with the need to special case the kallsyms- internal symbols by making them available even in the first linking stage. While it is a generated file, the patch includes the changes to scripts/genksyms/keywords.c_shipped, as I'm unsure what the procedure here is. Signed-off-by: NJan Beulich <jbeulich@novell.com> Signed-off-by: NSam Ravnborg <sam@ravnborg.org>
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- 19 12月, 2008 1 次提交
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由 Paul E. McKenney 提交于
This patch fixes a long-standing performance bug in classic RCU that results in massive internal-to-RCU lock contention on systems with more than a few hundred CPUs. Although this patch creates a separate flavor of RCU for ease of review and patch maintenance, it is intended to replace classic RCU. This patch still handles stress better than does mainline, so I am still calling it ready for inclusion. This patch is against the -tip tree. Nevertheless, experience on an actual 1000+ CPU machine would still be most welcome. Most of the changes noted below were found while creating an rcutiny (which should permit ejecting the current rcuclassic) and while doing detailed line-by-line documentation. Updates from v9 (http://lkml.org/lkml/2008/12/2/334): o Fixes from remainder of line-by-line code walkthrough, including comment spelling, initialization, undesirable narrowing due to type conversion, removing redundant memory barriers, removing redundant local-variable initialization, and removing redundant local variables. I do not believe that any of these fixes address the CPU-hotplug issues that Andi Kleen was seeing, but please do give it a whirl in case the machine is smarter than I am. A writeup from the walkthrough may be found at the following URL, in case you are suffering from terminal insomnia or masochism: http://www.kernel.org/pub/linux/kernel/people/paulmck/tmp/rcutree-walkthrough.2008.12.16a.pdf o Made rcutree tracing use seq_file, as suggested some time ago by Lai Jiangshan. o Added a .csv variant of the rcudata debugfs trace file, to allow people having thousands of CPUs to drop the data into a spreadsheet. Tested with oocalc and gnumeric. Updated documentation to suit. Updates from v8 (http://lkml.org/lkml/2008/11/15/139): o Fix a theoretical race between grace-period initialization and force_quiescent_state() that could occur if more than three jiffies were required to carry out the grace-period initialization. Which it might, if you had enough CPUs. o Apply Ingo's printk-standardization patch. o Substitute local variables for repeated accesses to global variables. o Fix comment misspellings and redundant (but harmless) increments of ->n_rcu_pending (this latter after having explicitly added it). o Apply checkpatch fixes. Updates from v7 (http://lkml.org/lkml/2008/10/10/291): o Fixed a number of problems noted by Gautham Shenoy, including the cpu-stall-detection bug that he was having difficulty convincing me was real. ;-) o Changed cpu-stall detection to wait for ten seconds rather than three in order to reduce false positive, as suggested by Ingo Molnar. o Produced a design document (http://lwn.net/Articles/305782/). The act of writing this document uncovered a number of both theoretical and "here and now" bugs as noted below. o Fix dynticks_nesting accounting confusion, simplify WARN_ON() condition, fix kerneldoc comments, and add memory barriers in dynticks interface functions. o Add more data to tracing. o Remove unused "rcu_barrier" field from rcu_data structure. o Count calls to rcu_pending() from scheduling-clock interrupt to use as a surrogate timebase should jiffies stop counting. o Fix a theoretical race between force_quiescent_state() and grace-period initialization. Yes, initialization does have to go on for some jiffies for this race to occur, but given enough CPUs... Updates from v6 (http://lkml.org/lkml/2008/9/23/448): o Fix a number of checkpatch.pl complaints. o Apply review comments from Ingo Molnar and Lai Jiangshan on the stall-detection code. o Fix several bugs in !CONFIG_SMP builds. o Fix a misspelled config-parameter name so that RCU now announces at boot time if stall detection is configured. o Run tests on numerous combinations of configurations parameters, which after the fixes above, now build and run correctly. Updates from v5 (http://lkml.org/lkml/2008/9/15/92, bad subject line): o Fix a compiler error in the !CONFIG_FANOUT_EXACT case (blew a changeset some time ago, and finally got around to retesting this option). o Fix some tracing bugs in rcupreempt that caused incorrect totals to be printed. o I now test with a more brutal random-selection online/offline script (attached). Probably more brutal than it needs to be on the people reading it as well, but so it goes. o A number of optimizations and usability improvements: o Make rcu_pending() ignore the grace-period timeout when there is no grace period in progress. o Make force_quiescent_state() avoid going for a global lock in the case where there is no grace period in progress. o Rearrange struct fields to improve struct layout. o Make call_rcu() initiate a grace period if RCU was idle, rather than waiting for the next scheduling clock interrupt. o Invoke rcu_irq_enter() and rcu_irq_exit() only when idle, as suggested by Andi Kleen. I still don't completely trust this change, and might back it out. o Make CONFIG_RCU_TRACE be the single config variable manipulated for all forms of RCU, instead of the prior confusion. o Document tracing files and formats for both rcupreempt and rcutree. Updates from v4 for those missing v5 given its bad subject line: o Separated dynticks interface so that NMIs and irqs call separate functions, greatly simplifying it. In particular, this code no longer requires a proof of correctness. ;-) o Separated dynticks state out into its own per-CPU structure, avoiding the duplicated accounting. o The case where a dynticks-idle CPU runs an irq handler that invokes call_rcu() is now correctly handled, forcing that CPU out of dynticks-idle mode. o Review comments have been applied (thank you all!!!). For but one example, fixed the dynticks-ordering issue that Manfred pointed out, saving me much debugging. ;-) o Adjusted rcuclassic and rcupreempt to handle dynticks changes. Attached is an updated patch to Classic RCU that applies a hierarchy, greatly reducing the contention on the top-level lock for large machines. This passes 10-hour concurrent rcutorture and online-offline testing on 128-CPU ppc64 without dynticks enabled, and exposes some timekeeping bugs in presence of dynticks (exciting working on a system where "sleep 1" hangs until interrupted...), which were fixed in the 2.6.27 kernel. It is getting more reliable than mainline by some measures, so the next version will be against -tip for inclusion. See also Manfred Spraul's recent patches (or his earlier work from 2004 at http://marc.info/?l=linux-kernel&m=108546384711797&w=2). We will converge onto a common patch in the fullness of time, but are currently exploring different regions of the design space. That said, I have already gratefully stolen quite a few of Manfred's ideas. This patch provides CONFIG_RCU_FANOUT, which controls the bushiness of the RCU hierarchy. Defaults to 32 on 32-bit machines and 64 on 64-bit machines. If CONFIG_NR_CPUS is less than CONFIG_RCU_FANOUT, there is no hierarchy. By default, the RCU initialization code will adjust CONFIG_RCU_FANOUT to balance the hierarchy, so strongly NUMA architectures may choose to set CONFIG_RCU_FANOUT_EXACT to disable this balancing, allowing the hierarchy to be exactly aligned to the underlying hardware. Up to two levels of hierarchy are permitted (in addition to the root node), allowing up to 16,384 CPUs on 32-bit systems and up to 262,144 CPUs on 64-bit systems. I just know that I am going to regret saying this, but this seems more than sufficient for the foreseeable future. (Some architectures might wish to set CONFIG_RCU_FANOUT=4, which would limit such architectures to 64 CPUs. If this becomes a real problem, additional levels can be added, but I doubt that it will make a significant difference on real hardware.) In the common case, a given CPU will manipulate its private rcu_data structure and the rcu_node structure that it shares with its immediate neighbors. This can reduce both lock and memory contention by multiple orders of magnitude, which should eliminate the need for the strange manipulations that are reported to be required when running Linux on very large systems. Some shortcomings: o More bugs will probably surface as a result of an ongoing line-by-line code inspection. Patches will be provided as required. o There are probably hangs, rcutorture failures, &c. Seems quite stable on a 128-CPU machine, but that is kind of small compared to 4096 CPUs. However, seems to do better than mainline. Patches will be provided as required. o The memory footprint of this version is several KB larger than rcuclassic. A separate UP-only rcutiny patch will be provided, which will reduce the memory footprint significantly, even compared to the old rcuclassic. One such patch passes light testing, and has a memory footprint smaller even than rcuclassic. Initial reaction from various embedded guys was "it is not worth it", so am putting it aside. Credits: o Manfred Spraul for ideas, review comments, and bugs spotted, as well as some good friendly competition. ;-) o Josh Triplett, Ingo Molnar, Peter Zijlstra, Mathieu Desnoyers, Lai Jiangshan, Andi Kleen, Andy Whitcroft, and Andrew Morton for reviews and comments. o Thomas Gleixner for much-needed help with some timer issues (see patches below). o Jon M. Tollefson, Tim Pepper, Andrew Theurer, Jose R. Santos, Andy Whitcroft, Darrick Wong, Nishanth Aravamudan, Anton Blanchard, Dave Kleikamp, and Nathan Lynch for keeping machines alive despite my heavy abuse^Wtesting. Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: NIngo Molnar <mingo@elte.hu>
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- 13 12月, 2008 1 次提交
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由 Rusty Russell 提交于
Impact: cleanup Each SMP arch defines these themselves. Move them to a central location. Twists: 1) Some archs (m32, parisc, s390) set possible_map to all 1, so we add a CONFIG_INIT_ALL_POSSIBLE for this rather than break them. 2) mips and sparc32 '#define cpu_possible_map phys_cpu_present_map'. Those archs simply have phys_cpu_present_map replaced everywhere. 3) Alpha defined cpu_possible_map to cpu_present_map; this is tricky so I just manipulate them both in sync. 4) IA64, cris and m32r have gratuitous 'extern cpumask_t cpu_possible_map' declarations. Signed-off-by: NRusty Russell <rusty@rustcorp.com.au> Reviewed-by: NGrant Grundler <grundler@parisc-linux.org> Tested-by: NTony Luck <tony.luck@intel.com> Acked-by: NIngo Molnar <mingo@elte.hu> Cc: Mike Travis <travis@sgi.com> Cc: ink@jurassic.park.msu.ru Cc: rmk@arm.linux.org.uk Cc: starvik@axis.com Cc: tony.luck@intel.com Cc: takata@linux-m32r.org Cc: ralf@linux-mips.org Cc: grundler@parisc-linux.org Cc: paulus@samba.org Cc: schwidefsky@de.ibm.com Cc: lethal@linux-sh.org Cc: wli@holomorphy.com Cc: davem@davemloft.net Cc: jdike@addtoit.com Cc: mingo@redhat.com
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