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* [PATCH] remove redundant NULL check before before kfree() in kernel/sysctl.cJesper Juhl2005-06-25
| | | | | | Signed-off-by: Jesper Juhl <juhl-lkml@dif.dk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] kernel/timer: fix msleep_interruptible() commentDomen Puncer2005-06-25
| | | | | | | | | | The comment for msleep_interruptible() is wrong, as it will ignore wait-queue events, but will wake up early for signals. Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com> Signed-off-by: Domen Puncer <domen@coderock.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] kexec code cleanupManeesh Soni2005-06-25
| | | | | | | | | | | | | | | | | o Following patch provides purely cosmetic changes and corrects CodingStyle guide lines related certain issues like below in kexec related files o braces for one line "if" statements, "for" loops, o more than 80 column wide lines, o No space after "while", "for" and "switch" key words o Changes: o take-2: Removed the extra tab before "case" key words. o take-3: Put operator at the end of line and space before "*/" Signed-off-by: Maneesh Soni <maneesh@in.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] kdump: Use real pt_regs from exceptionAlexander Nyberg2005-06-25
| | | | | | | | | | | | | | | | | | | | | Makes kexec_crashdump() take a pt_regs * as an argument. This allows to get exact register state at the point of the crash. If we come from direct panic assertion NULL will be passed and the current registers saved before crashdump. This hooks into two places: die(): check the conditions under which we will panic when calling do_exit and go there directly with the pt_regs that caused the fatal fault. die_nmi(): If we receive an NMI lockup while in the kernel use the pt_regs and go directly to crash_kexec(). We're probably nested up badly at this point so this might be the only chance to escape with proper information. Signed-off-by: Alexander Nyberg <alexn@telia.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] kdump: Access dump file in elf format (/proc/vmcore)Vivek Goyal2005-06-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | From: "Vivek Goyal" <vgoyal@in.ibm.com> o Support for /proc/vmcore interface. This interface exports elf core image either in ELF32 or ELF64 format, depending on the format in which elf headers have been stored by crashed kernel. o Added support for CONFIG_VMCORE config option. o Removed the dependency on /proc/kcore. From: "Eric W. Biederman" <ebiederm@xmission.com> This patch has been refactored to more closely match the prevailing style in the affected files. And to clearly indicate the dependency between /proc/kcore and proc/vmcore.c From: Hariprasad Nellitheertha <hari@in.ibm.com> This patch contains the code that provides an ELF format interface to the previous kernel's memory post kexec reboot. Signed off by Hariprasad Nellitheertha <hari@in.ibm.com> Signed-off-by: Eric Biederman <ebiederm@xmission.com> Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Retrieve elfcorehdr address from command lineVivek Goyal2005-06-25
| | | | | | | | | This patch adds support for retrieving the address of elf core header if one is passed in command line. Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] kdump: Routines for copying dump pagesVivek Goyal2005-06-25
| | | | | | | | | | | This patch provides the interfaces necessary to read the dump contents, treating it as a high memory device. Signed off by Hariprasad Nellitheertha <hari@in.ibm.com> Signed-off-by: Eric Biederman <ebiederm@xmission.com> Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Kdump: Export crash notes section address through sysfsVivek Goyal2005-06-25
| | | | | | | | | o Following patch exports kexec global variable "crash_notes" to user space through sysfs as kernel attribute in /sys/kernel. Signed-off-by: Maneesh Soni <maneesh@in.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Kexec on panic vmlinux initrd fixVivek Goyal2005-06-25
| | | | | | | | | | | | | | | | | This is a minor bug fix in kexec to resolve the problem of loading panic kernel with initrd. o Problem: Loading a capture kenrel fails if initrd is also being loaded. This has been observed for vmlinux image for kexec on panic case. o This patch fixes the problem. In segment location and size verification logic, minor correction has been done. Segment memory end (mend) should be mstart + memsz - 1. This one byte offset was source of failure for initrd loading which was being loaded at hole boundary. Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] kexec: add kexec syscallsEric W. Biederman2005-06-25
| | | | | | | | | | | | | | | | | | | | This patch introduces the architecture independent implementation the sys_kexec_load, the compat_sys_kexec_load system calls. Kexec on panic support has been integrated into the core patch and is relatively clean. In addition the hopefully architecture independent option crashkernel=size@location has been docuemented. It's purpose is to reserve space for the panic kernel to live, and where no DMA transfer will ever be setup to access. Signed-off-by: Eric Biederman <ebiederm@xmission.com> Signed-off-by: Alexander Nyberg <alexn@telia.com> Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Vivek Goyal <vgoyal@in.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] sched: voluntary kernel preemptionIngo Molnar2005-06-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds a new preemption model: 'Voluntary Kernel Preemption'. The 3 models can be selected from a new menu: (X) No Forced Preemption (Server) ( ) Voluntary Kernel Preemption (Desktop) ( ) Preemptible Kernel (Low-Latency Desktop) we still default to the stock (Server) preemption model. Voluntary preemption works by adding a cond_resched() (reschedule-if-needed) call to every might_sleep() check. It is lighter than CONFIG_PREEMPT - at the cost of not having as tight latencies. It represents a different latency/complexity/overhead tradeoff. It has no runtime impact at all if disabled. Here are size stats that show how the various preemption models impact the kernel's size: text data bss dec hex filename 3618774 547184 179896 4345854 424ffe vmlinux.stock 3626406 547184 179896 4353486 426dce vmlinux.voluntary +0.2% 3748414 548640 179896 4476950 445016 vmlinux.preempt +3.5% voluntary-preempt is +0.2% of .text, preempt is +3.5%. This feature has been tested for many months by lots of people (and it's also included in the RHEL4 distribution and earlier variants were in Fedora as well), and it's intended for users and distributions who dont want to use full-blown CONFIG_PREEMPT for one reason or another. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] enable PREEMPT_BKL on !PREEMPT+SMP tooIngo Molnar2005-06-25
| | | | | | | | | | | | | | | | | | | | | | | The only sane way to clean up the current 3 lock_kernel() variants seems to be to remove the spinlock-based BKL implementations altogether, and to keep the semaphore-based one only. If we dont want to do that for whatever reason then i'm afraid we have to live with the current complexity. (but i'm open for other cleanup suggestions as well.) To explore this possibility we'll (at a minimum) have to know whether the semaphore-based BKL works fine on plain SMP too. The patch below enables this. The patch may make sense in isolation as well, as it might bring performance benefits: code that would formerly spin on the BKL spinlock will now schedule away and give up the CPU. It might introduce performance regressions as well, if any performance-critical code uses the BKL heavily and gets overscheduled due to the semaphore. I very much hope there is no such performance-critical codepath left though. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] consolidate PREEMPT options into kernel/Kconfig.preemptIngo Molnar2005-06-25
| | | | | | | | | | | This patch consolidates the CONFIG_PREEMPT and CONFIG_PREEMPT_BKL preemption options into kernel/Kconfig.preempt. This, besides reducing source-code, also enables more centralized tweaking of preemption related options. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Dynamic sched domains: cpuset changesDinakar Guniguntala2005-06-25
| | | | | | | | | | Adds the core update_cpu_domains code and updated cpusets documentation Signed-off-by: Dinakar Guniguntala <dino@in.ibm.com> Acked-by: Paul Jackson <pj@sgi.com> Acked-by: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Dynamic sched domains: sched changesDinakar Guniguntala2005-06-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The following patches add dynamic sched domains functionality that was extensively discussed on lkml and lse-tech. I would like to see this added to -mm o The main advantage with this feature is that it ensures that the scheduler load balacing code only balances against the cpus that are in the sched domain as defined by an exclusive cpuset and not all of the cpus in the system. This removes any overhead due to load balancing code trying to pull tasks outside of the cpu exclusive cpuset only to be prevented by the tasks' cpus_allowed mask. o cpu exclusive cpusets are useful for servers running orthogonal workloads such as RT applications requiring low latency and HPC applications that are throughput sensitive o It provides a new API partition_sched_domains in sched.c that makes dynamic sched domains possible. o cpu_exclusive cpusets sets are now associated with a sched domain. Which means that the users can dynamically modify the sched domains through the cpuset file system interface o ia64 sched domain code has been updated to support this feature as well o Currently, this does not support hotplug. (However some of my tests indicate hotplug+preempt is currently broken) o I have tested it extensively on x86. o This should have very minimal impact on performance as none of the fast paths are affected Signed-off-by: Dinakar Guniguntala <dino@in.ibm.com> Acked-by: Paul Jackson <pj@sgi.com> Acked-by: Nick Piggin <nickpiggin@yahoo.com.au> Acked-by: Matthew Dobson <colpatch@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Changing RT priority without CAP_SYS_NICEOlivier Croquette2005-06-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Presently, a process without the capability CAP_SYS_NICE can not change its own policy, which is OK. But it can also not decrease its RT priority (if scheduled with policy SCHED_RR or SCHED_FIFO), which is what this patch changes. The rationale is the same as for the nice value: a process should be able to require less priority for itself. Increasing the priority is still not allowed. This is for example useful if you give a multithreaded user process a RT priority, and the process would like to organize its internal threads using priorities also. Then you can give the process the highest priority needed N, and the process starts its threads with lower priorities: N-1, N-2... The POSIX norm says that the permissions are implementation specific, so I think we can do that. In a sense, it makes the permissions consistent whatever the policy is: with this patch, process scheduled by SCHED_FIFO, SCHED_RR and SCHED_OTHER can all decrease their priority. From: Ingo Molnar <mingo@elte.hu> cleaned up and merged to -mm. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] sched: micro-optimize task requeueing in schedule()Chen Shang2005-06-25
| | | | | | | | micro-optimize task requeueing in schedule() & clean up recalc_task_prio(). Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] sched: relax pinned balancingNick Piggin2005-06-25
| | | | | | | | | | | | | | | | | The maximum rebalance interval allowed by the multiprocessor balancing backoff is often not large enough to handle corner cases where there are lots of tasks pinned on a CPU. Suresh reported: I see system livelock's if for example I have 7000 processes pinned onto one cpu (this is on the fastest 8-way system I have access to). After this patch, the machine is reported to go well above this number. Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] sched: consolidate sbe sbfNick Piggin2005-06-25
| | | | | | | | | | | | | | | | Consolidate balance-on-exec with balance-on-fork. This is made easy by the sched-domains RCU patches. As well as the general goodness of code reduction, this allows the runqueues to be unlocked during balance-on-fork. schedstats is a problem. Maybe just have balance-on-event instead of distinguishing fork and exec? Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] sched: RCU domainsNick Piggin2005-06-25
| | | | | | | | | | | | | | | | | | | | | | | | One of the problems with the multilevel balance-on-fork/exec is that it needs to jump through hoops to satisfy sched-domain's locking semantics (that is, you may traverse your own domain when not preemptable, and you may traverse others' domains when holding their runqueue lock). balance-on-exec had to potentially migrate between more than one CPU before finding a final CPU to migrate to, and balance-on-fork needed to potentially take multiple runqueue locks. So bite the bullet and make sched-domains go completely RCU. This actually simplifies the code quite a bit. From: Ingo Molnar <mingo@elte.hu> schedstats RCU fix, and a nice comment on for_each_domain, from Ingo. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] sched: multilevel sbe sbfNick Piggin2005-06-25
| | | | | | | | | | | | | | | | | The fundamental problem that Suresh has with balance on exec and fork is that it only tries to balance the top level domain with the flag set. This was worked around by removing degenerate domains, but is still a problem if people want to start using more complex sched-domains, especially multilevel NUMA that ia64 is already using. This patch makes balance on fork and exec try balancing over not just the top most domain with the flag set, but all the way down the domain tree. Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] sched: remove degenerate domainsSuresh Siddha2005-06-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Remove degenerate scheduler domains during the sched-domain init. For example on x86_64, we always have NUMA configured in. On Intel EM64T systems, top most sched domain will be of NUMA and with only one sched_group in it. With fork/exec balances(recent Nick's fixes in -mm tree), we always endup taking wrong decisions because of this topmost domain (as it contains only one group and find_idlest_group always returns NULL). We will endup loading HT package completely first, letting active load balance kickin and correct it. In general, this patch also makes sense with out recent Nick's fixes in -mm. From: Nick Piggin <nickpiggin@yahoo.com.au> Modified to account for more than just sched_groups when scanning for degenerate domains by Nick Piggin. And allow a runqueue's sd to go NULL rather than keep a single degenerate domain around (this happens when you run with maxcpus=1). Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] sched: null domainsNick Piggin2005-06-25
| | | | | | | | | | | | | Fix the last 2 places that directly access a runqueue's sched-domain and assume it cannot be NULL. That allows the use of NULL for domain, instead of a dummy domain, to signify no balancing is to happen. No functional changes. Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] sched: cleanup context switch lockingNick Piggin2005-06-25
| | | | | | | | | | | | | | | | Instead of requiring architecture code to interact with the scheduler's locking implementation, provide a couple of defines that can be used by the architecture to request runqueue unlocked context switches, and ask for interrupts to be enabled over the context switch. Also replaces the "switch_lock" used by these architectures with an oncpu flag (note, not a potentially slow bitflag). This eliminates one bus locked memory operation when context switching, and simplifies the task_running function. Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] sched: uninline task_timesliceIngo Molnar2005-06-25
| | | | | | | | | | | "Chen, Kenneth W" <kenneth.w.chen@intel.com> uninline task_timeslice() - reduces code footprint noticeably, and it's slowpath code. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] sched: schedstats update for balance on forkNick Piggin2005-06-25
| | | | | | | | Add SCHEDSTAT statistics for sched-balance-fork. Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] sched: balance on forkNick Piggin2005-06-25
| | | | | | | | | | | | | | | | | | Reimplement the balance on exec balancing to be sched-domains aware. Use this to also do balance on fork balancing. Make x86_64 do balance on fork over the NUMA domain. The problem that the non sched domains aware blancing became apparent on dual core, multi socket opterons. What we want is for the new tasks to be sent to a different socket, but more often than not, we would first load up our sibling core, or fill two cores of a single remote socket before selecting a new one. This gives large improvements to STREAM on such systems. Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] sched: no aggressive idle balancingNick Piggin2005-06-25
| | | | | | | | | | Remove the very aggressive idle stuff that has recently gone into 2.6 - it is going against the direction we are trying to go. Hopefully we can regain performance through other methods. Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] sched: tweak affine wakeupsNick Piggin2005-06-25
| | | | | | | | | | | | | | | | | | Do less affine wakeups. We're trying to reduce dbt2-pgsql idle time regressions here... make sure we don't don't move tasks the wrong way in an imbalance condition. Also, remove the cache coldness requirement from the calculation - this seems to induce sharp cutoff points where behaviour will suddenly change on some workloads if the load creeps slightly over or under some point. It is good for periodic balancing because in that case have otherwise have no other context to determine what task to move. But also make a minor tweak to "wake balancing" - the imbalance tolerance is now set at half the domain's imbalance, so we get the opportunity to do wake balancing before the more random periodic rebalancing gets preformed. Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] sched: balance timersNick Piggin2005-06-25
| | | | | | | | | | | | | Do CPU load averaging over a number of different intervals. Allow each interval to be chosen by sending a parameter to source_load and target_load. 0 is instantaneous, idx > 0 returns a decaying average with the most recent sample weighted at 2^(idx-1). To a maximum of 3 (could be easily increased). So generally a higher number will result in more conservative balancing. Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] sched: less aggressive idle balancingNick Piggin2005-06-25
| | | | | | | | | | Remove the special casing for idle CPU balancing. Things like this are hurting for example on SMT, where are single sibling being idle doesn't really warrant a really aggressive pull over the NUMA domain, for example. Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] sched: add debuggingNick Piggin2005-06-25
| | | | | | | | | These conditions should now be impossible, and we need to fix them if they happen. Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] sched: fix SMT scheduling problemsNick Piggin2005-06-25
| | | | | | | | | | | | | | | | | | | | | | | | SMT balancing has a couple of problems. Firstly, active_load_balance is too complex - basically it should be a dumb helper for when the periodic balancer has determined there is an imbalance, but gets stuck because the task is running. So rip out all its "smarts", and just make it move one task to the target CPU. Second, the busy CPU's sched-domain tree was being used for active balancing. This means that it may not see that nr_balance_failed has reached a critical level. So use the target CPU's sched-domain tree for this. We can do this because we hold its runqueue lock. Lastly, reset nr_balance_failed to a point where we allow cache hot migration. This will help ensure active load balancing is successful. Thanks to Suresh Siddha for pointing out these issues. Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] sched: reduce active load balancingNick Piggin2005-06-25
| | | | | | | | | | | Fix up active load balancing a bit so it doesn't get called when it shouldn't. Reset the nr_balance_failed counter at more points where we have found conditions to be balanced. This reduces too aggressive active balancing seen on some workloads. Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] sched: improve load balancing pinned tasksNick Piggin2005-06-25
| | | | | | | | | | | | | | | | | | | | | | | | John Hawkes explained the problem best: A large number of processes that are pinned to a single CPU results in every other CPU's load_balance() seeing this overloaded CPU as "busiest", yet move_tasks() never finds a task to pull-migrate. This condition occurs during module unload, but can also occur as a denial-of-service using sys_sched_setaffinity(). Several hundred CPUs performing this fruitless load_balance() will livelock on the busiest CPU's runqueue lock. A smaller number of CPUs will livelock if the pinned task count gets high. Expanding slightly on John's patch, this one attempts to work out whether the balancing failure has been due to too many tasks pinned on the runqueue. This allows it to be basically invisible to the regular blancing paths (ie. when there are no pinned tasks). We can use this extra knowledge to shut down the balancing faster, and ensure the migration threads don't start running which is another problem observed in the wild. Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] sched: cleanup wake_idleNick Piggin2005-06-25
| | | | | | | | | New sched-domains code means we don't get spans with offline CPUs in them. Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] swsusp: only allow it when it makes sensePavel Machek2005-06-25
| | | | | | | | | | | | | | Show swsuspend only on .config where it can compile. I got this on PPC32 && SMP: kernel/power/smp.c:24: error: storage size of `ctxt' isn't known Also mark swsusp as no longer experimental. Signed-off-by: Olaf Hering <olh@suse.de> Signed-off-by: Pavel Machek <pavel@suse.cz> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] CPU hotplug printk fixShaohua Li2005-06-25
| | | | | | | | | | | In the cpu hotplug case, per-cpu data possibly isn't initialized even the system state is 'running'. As the comments say in the original code, some console drivers assume per-cpu resources have been allocated. radeon fb is one such driver, which uses kmalloc. After a CPU is down, the per-cpu data of slab is freed, so the system crashed when printing some info. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] swsusp: fix nr_copy_pagesPavel Machek2005-06-25
| | | | | | | | | | | | | The following patch moves the recalculation of nr_copy_pages so that the right number is used in the calculation of the size of memory and swap needed. It prevents swsusp from attempting to suspend if there is not enough memory and/or swap (which is unlikely anyway). Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Pavel Machek <pavel@suse.cz> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] swsusp: cleanup whitespacePavel Machek2005-06-25
| | | | | | | | | | | | | | The following patch cleans up whitespace in swsusp.c (a bit): - removes any trailing whitespace - adds spaces after if, for, for_each_pbe, for_each_zone etc., wherever necessary. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Pavel Machek <pavel@suse.cz> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] swsusp: kill unneccessary does_collide_orderPavel Machek2005-06-25
| | | | | | | | | | | | The following patch removes the unnecessary function does_collide_order(). This function is no longer necessary, as currently there are only 0-order allocations in swsusp, and the use of it is confusing. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Pavel Machek <pavel@suse.cz> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] properly stop devices before poweroffPavel Machek2005-06-25
| | | | | | | | | Without this patch, Linux provokes emergency disk shutdowns and similar nastiness. It was in SuSE kernels for some time, IIRC. Signed-off-by: Pavel Machek <pavel@suse.cz> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] suspend/resume SMP supportLi Shaohua2005-06-25
| | | | | | | | | | Using CPU hotplug to support suspend/resume SMP. Both S3 and S4 use disable/enable_nonboot_cpus API. The S4 part is based on Pavel's original S4 SMP patch. Signed-off-by: Li Shaohua<shaohua.li@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] i386 CPU hotplugZwane Mwaikambo2005-06-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | (The i386 CPU hotplug patch provides infrastructure for some work which Pavel is doing as well as for ACPI S3 (suspend-to-RAM) work which Li Shaohua <shaohua.li@intel.com> is doing) The following provides i386 architecture support for safely unregistering and registering processors during runtime, updated for the current -mm tree. In order to avoid dumping cpu hotplug code into kernel/irq/* i dropped the cpu_online check in do_IRQ() by modifying fixup_irqs(). The difference being that on cpu offline, fixup_irqs() is called before we clear the cpu from cpu_online_map and a long delay in order to ensure that we never have any queued external interrupts on the APICs. There are additional changes to s390 and ppc64 to account for this change. 1) Add CONFIG_HOTPLUG_CPU 2) disable local APIC timer on dead cpus. 3) Disable preempt around irq balancing to prevent CPUs going down. 4) Print irq stats for all possible cpus. 5) Debugging check for interrupts on offline cpus. 6) Hacky fixup_irqs() to redirect irqs when cpus go off/online. 7) play_dead() for offline cpus to spin inside. 8) Handle offline cpus set in flush_tlb_others(). 9) Grab lock earlier in smp_call_function() to prevent CPUs going down. 10) Implement __cpu_disable() and __cpu_die(). 11) Enable local interrupts in cpu_enable() after fixup_irqs() 12) Don't fiddle with NMI on dead cpu, but leave intact on other cpus. 13) Program IRQ affinity whilst cpu is still in cpu_online_map on offline. Signed-off-by: Zwane Mwaikambo <zwane@linuxpower.ca> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] make various thing staticAdrian Bunk2005-06-24
| | | | | | | | Another rollup of patches which give various symbols static scope Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] modules: add version and srcversion to sysfsMatt Domsch2005-06-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds version and srcversion files to /sys/module/${modulename} containing the version and srcversion fields of the module's modinfo section (if present). /sys/module/e1000 |-- srcversion `-- version This patch differs slightly from the version posted in January, as it now uses the new kstrdup() call in -mm. Why put this in sysfs? a) Tools like DKMS, which deal with changing out individual kernel modules without replacing the whole kernel, can behave smarter if they can tell the version of a given module. The autoinstaller feature, for example, which determines if your system has a "good" version of a driver (i.e. if the one provided by DKMS has a newer verson than that provided by the kernel package installed), and to automatically compile and install a newer version if DKMS has it but your kernel doesn't yet have that version. b) Because sysadmins manually, or with tools like DKMS, can switch out modules on the file system, you can't count on 'modinfo foo.ko', which looks at /lib/modules/${kernelver}/... actually matching what is loaded into the kernel already. Hence asking sysfs for this. c) as the unbind-driver-from-device work takes shape, it will be possible to rebind a driver that's built-in (no .ko to modinfo for the version) to a newly loaded module. sysfs will have the currently-built-in version info, for comparison. d) tech support scripts can then easily grab the version info for what's running presently - a question I get often. There has been renewed interest in this patch on linux-scsi by driver authors. As the idea originated from GregKH, I leave his Signed-off-by: intact, though the implementation is nearly completely new. Compiled and run on x86 and x86_64. From: Matthew Dobson <colpatch@us.ibm.com> build fix From: Thierry Vignaud <tvignaud@mandriva.com> build fix From: Matthew Dobson <colpatch@us.ibm.com> warning fix Signed-off-by: Greg Kroah-Hartman <greg@kroah.com> Signed-off-by: Matt Domsch <Matt_Domsch@dell.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Keys: Make request-key create an authorisation keyDavid Howells2005-06-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The attached patch makes the following changes: (1) There's a new special key type called ".request_key_auth". This is an authorisation key for when one process requests a key and another process is started to construct it. This type of key cannot be created by the user; nor can it be requested by kernel services. Authorisation keys hold two references: (a) Each refers to a key being constructed. When the key being constructed is instantiated the authorisation key is revoked, rendering it of no further use. (b) The "authorising process". This is either: (i) the process that called request_key(), or: (ii) if the process that called request_key() itself had an authorisation key in its session keyring, then the authorising process referred to by that authorisation key will also be referred to by the new authorisation key. This means that the process that initiated a chain of key requests will authorise the lot of them, and will, by default, wind up with the keys obtained from them in its keyrings. (2) request_key() creates an authorisation key which is then passed to /sbin/request-key in as part of a new session keyring. (3) When request_key() is searching for a key to hand back to the caller, if it comes across an authorisation key in the session keyring of the calling process, it will also search the keyrings of the process specified therein and it will use the specified process's credentials (fsuid, fsgid, groups) to do that rather than the calling process's credentials. This allows a process started by /sbin/request-key to find keys belonging to the authorising process. (4) A key can be read, even if the process executing KEYCTL_READ doesn't have direct read or search permission if that key is contained within the keyrings of a process specified by an authorisation key found within the calling process's session keyring, and is searchable using the credentials of the authorising process. This allows a process started by /sbin/request-key to read keys belonging to the authorising process. (5) The magic KEY_SPEC_*_KEYRING key IDs when passed to KEYCTL_INSTANTIATE or KEYCTL_NEGATE will specify a keyring of the authorising process, rather than the process doing the instantiation. (6) One of the process keyrings can be nominated as the default to which request_key() should attach new keys if not otherwise specified. This is done with KEYCTL_SET_REQKEY_KEYRING and one of the KEY_REQKEY_DEFL_* constants. The current setting can also be read using this call. (7) request_key() is partially interruptible. If it is waiting for another process to finish constructing a key, it can be interrupted. This permits a request-key cycle to be broken without recourse to rebooting. Signed-Off-By: David Howells <dhowells@redhat.com> Signed-Off-By: Benoit Boissinot <benoit.boissinot@ens-lyon.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Keys: Pass session keyring to call_usermodehelper()David Howells2005-06-24
| | | | | | | | | | | The attached patch makes it possible to pass a session keyring through to the process spawned by call_usermodehelper(). This allows patch 3/3 to pass an authorisation key through to /sbin/request-key, thus permitting better access controls when doing just-in-time key creation. Signed-Off-By: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] aio: make wait_queue ->task ->privateBenjamin LaHaise2005-06-23
| | | | | | | | | | | In the upcoming aio_down patch, it is useful to store a private data pointer in the kiocb's wait_queue. Since we provide our own wake up function and do not require the task_struct pointer, it makes sense to convert the task pointer into a generic private pointer. Signed-off-by: Benjamin LaHaise <benjamin.c.lahaise@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] Optimize sys_times for a single thread processChristoph Lameter2005-06-23
| | | | | | | | | | | | Avoid taking the tasklist_lock in sys_times if the process is single threaded. In a NUMA system taking the tasklist_lock may cause a bouncing cacheline if multiple independent processes continually call sys_times to measure their performance. Signed-off-by: Christoph Lameter <christoph@lameter.com> Signed-off-by: Shai Fultheim <shai@scalex86.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>