linux/include/asm-generic, branch v2.6.19

Add "pure_initcall" for static variable initialization

2006-11-20T19:47:18Z

This is a quick hack to overcome the fact that SRCU currently does not allow static initializers, and we need to sometimes initialize those things before any other initializers (even "core" ones) can do so. Currently we don't allow this at all for modules, and the only user that needs is right now is cpufreq. As reported by Thomas Gleixner: "Commit b4dfdbb3c707474a2254c5b4d7e62be31a4b7da9 ("[PATCH] cpufreq: make the transition_notifier chain use SRCU breaks cpu frequency notification users, which register the callback > on core_init level." Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Arjan van de Ven Cc: Andrew Morton , Signed-off-by: Linus Torvalds

[PATCH] drivers: wait for threaded probes between initcall levels

2006-10-27T22:34:51Z

The multithreaded-probing code has a problem: after one initcall level (eg, core_initcall) has been processed, we will then start processing the next level (postcore_initcall) while the kernel threads which are handling core_initcall are still executing. This breaks the guarantees which the layered initcalls previously gave us. IOW, we want to be multithreaded _within_ an initcall level, but not between different levels. Fix that up by causing the probing code to wait for all outstanding probes at one level to complete before we start processing the next level. Cc: Greg KH Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] vmlinux.lds: consolidate initcall sections

2006-10-27T22:34:51Z

Add a vmlinux.lds.h helper macro for defining the eight-level initcall table, teach all the architectures to use it. This is a prerequisite for a patch which performs initcall synchronisation for multithreaded-probing. Cc: Greg KH Signed-off-by: Andrew Morton [ Added AVR32 as well ] Signed-off-by: Haavard Skinnemoen Signed-off-by: Linus Torvalds

[PATCH] x86-64: Speed up dwarf2 unwinder

2006-10-21T16:37:01Z

This changes the dwarf2 unwinder to do a binary search for CIEs instead of a linear work. The linker is unfortunately not able to build a proper lookup table at link time, instead it creates one at runtime as soon as the bootmem allocator is usable (so you'll continue using the linear lookup for the first [hopefully] few calls). The code should be ready to utilize a build-time created table once a fixed linker becomes available. Signed-off-by: Jan Beulich Signed-off-by: Andi Kleen

[PATCH] Fix warnings for WARN_ON if CONFIG_BUG is disabled

2006-10-20T17:26:38Z

In most cases the return value of WARN_ON() is ignored. If the generic definition for the !CONFIG_BUG case is used this will result in a warning: CC kernel/sched.o In file included from include/linux/bio.h:25, from include/linux/blkdev.h:14, from kernel/sched.c:39: include/linux/ioprio.h: In function âtask_ioprioâ: include/linux/ioprio.h:50: warning: statement with no effect kernel/sched.c: In function âcontext_switchâ: kernel/sched.c:1834: warning: statement with no effect Signed-off-by: Ralf Baechle Cc: Jeremy Fitzhardinge Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] sched: likely profiling

2006-10-11T18:14:22Z

This likely profiling is pretty fun. I found a few possible problems in sched.c. This patch may be not measurable, but when I did measure long ago, nooping (un)likely cost a couple of % on scheduler heavy benchmarks, so it all adds up. Tweak some branch hints: - the 2nd 64 bits in the bitmask is likely to be populated, because it contains the first 28 bits (nearly 3/4) of the normal priorities. (ratio of 669669:691 ~= 1000:1). - it isn't unlikely that context switching switches to another process. it might be very rapidly switching to and from the idle process (ratio of 475815:419004 and 471330:423544). Let the branch predictor decide. - preempt_enable seems to be very often called in a nested preempt_disable or with interrupts disabled (ratio of 3567760:87965 ~= 40:1) Signed-off-by: Nick Piggin Acked-by: Ingo Molnar Cc: Daniel Walker Cc: Hua Zhong Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] Fix typo in "syntax error if percpu macros are incorrectly used" patch

2006-10-06T15:53:41Z

Trivial typo fix in the "syntax error if percpu macros are incorrectly used" patch. I misspelled "identifier" in all places. D'Oh! Thanks to Dirk Mueller to point this out. Signed-off-by: Jan Blunck Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

[PATCH] Fix WARN_ON / WARN_ON_ONCE regression

2006-10-06T15:53:39Z

Tim and Ananiev report that the recent WARN_ON_ONCE changes cause increased cache misses with the tbench workload. Apparently due to the access to the newly-added static variable. Rearrange the code so that we don't touch that variable unless the warning is going to trigger. Also rework the logic so that the static variable starts out at zero, so we can move it into bss. It would seem logical to mark the static variable as __read_mostly too. But it would be wrong, because that would put it back into the vmlinux image, and the kernel will never read from this variable in normal operation anyway. Unless the compiler or hardware go and do some prefetching on us? For some reason this patch shrinks softirq.o text by 40 bytes. Cc: Tim Chen Cc: Herbert Xu Cc: "Ananiev, Leonid I" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

IRQ: Maintain regs pointer globally rather than passing to IRQ handlers

2006-10-05T14:10:12Z

Maintain a per-CPU global "struct pt_regs *" variable which can be used instead of passing regs around manually through all ~1800 interrupt handlers in the Linux kernel. The regs pointer is used in few places, but it potentially costs both stack space and code to pass it around. On the FRV arch, removing the regs parameter from all the genirq function results in a 20% speed up of the IRQ exit path (ie: from leaving timer_interrupt() to leaving do_IRQ()). Where appropriate, an arch may override the generic storage facility and do something different with the variable. On FRV, for instance, the address is maintained in GR28 at all times inside the kernel as part of general exception handling. Having looked over the code, it appears that the parameter may be handed down through up to twenty or so layers of functions. Consider a USB character device attached to a USB hub, attached to a USB controller that posts its interrupts through a cascaded auxiliary interrupt controller. A character device driver may want to pass regs to the sysrq handler through the input layer which adds another few layers of parameter passing. I've build this code with allyesconfig for x86_64 and i386. I've runtested the main part of the code on FRV and i386, though I can't test most of the drivers. I've also done partial conversion for powerpc and MIPS - these at least compile with minimal configurations. This will affect all archs. Mostly the changes should be relatively easy. Take do_IRQ(), store the regs pointer at the beginning, saving the old one: struct pt_regs *old_regs = set_irq_regs(regs); And put the old one back at the end: set_irq_regs(old_regs); Don't pass regs through to generic_handle_irq() or __do_IRQ(). In timer_interrupt(), this sort of change will be necessary: - update_process_times(user_mode(regs)); - profile_tick(CPU_PROFILING, regs); + update_process_times(user_mode(get_irq_regs())); + profile_tick(CPU_PROFILING); I'd like to move update_process_times()'s use of get_irq_regs() into itself, except that i386, alone of the archs, uses something other than user_mode(). Some notes on the interrupt handling in the drivers: (*) input_dev() is now gone entirely. The regs pointer is no longer stored in the input_dev struct. (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking. It does something different depending on whether it's been supplied with a regs pointer or not. (*) Various IRQ handler function pointers have been moved to type irq_handler_t. Signed-Off-By: David Howells (cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)

fix file specification in comments

2006-10-03T21:01:26Z

Many files include the filename at the beginning, serveral used a wrong one. Signed-off-by: Uwe Zeisberger Signed-off-by: Adrian Bunk