kernel_samsung_sm7125

jenna

History

David Howells 7d12e780e0 IRQ: Maintain regs pointer globally rather than passing to IRQ handlers 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 <dhowells@redhat.com> (cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)		19 years ago
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Makefile	[MIPS] lockdep: Add STACKTRACE_SUPPORT and enable LOCKDEP_SUPPORT	19 years ago
apm.c	[MIPS] Don't include obsolete <linux/config.h>.	19 years ago
asm-offsets.c	Remove obsolete #include <linux/config.h>	19 years ago
binfmt_elfn32.c	[MIPS] jiffies_to_compat_timeval fix	19 years ago
binfmt_elfo32.c	[MIPS] jiffies_to_compat_timeval fix	19 years ago
branch.c	[MIPS] Unify mips_fpu_soft_struct and mips_fpu_hard_structs.	19 years ago
cpu-bugs64.c	Remove obsolete #include <linux/config.h>	19 years ago
cpu-probe.c	[MIPS] Reduce race between cpu_wait() and need_resched() checking	19 years ago
dma-no-isa.c	…
entry.S	[MIPS] TRACE_IRQFLAGS_SUPPORT support.	19 years ago
gdb-low.S	[MIPS] TRACE_IRQFLAGS_SUPPORT support.	19 years ago
gdb-stub.c	Remove obsolete #include <linux/config.h>	19 years ago
genex.S	[MIPS] Stacktrace build-fix and improvement	19 years ago
head.S	[MIPS] TRACE_IRQFLAGS_SUPPORT support.	19 years ago
i8253.c	Input: pcspkr - separate device and driver registration	19 years ago
i8259.c	[MIPS] Update i8259 resources.	19 years ago
init_task.c	[PATCH] nsproxy: move init_nsproxy into kernel/nsproxy.c	19 years ago
irix5sys.S	…
irixelf.c	[PATCH] FDPIC: Move roundup() into linux/kernel.h	19 years ago
irixinv.c	…
irixioctl.c	…
irixsig.c	[MIPS] Move definition of IRIX compat constant into IRIX compat code.	19 years ago
irq-msc01.c	[MIPS] Eleminate interrupt migration helper use.	19 years ago
irq-mv6434x.c	[MIPS] Eleminate interrupt migration helper use.	19 years ago
irq-rm7000.c	[MIPS] Eleminate interrupt migration helper use.	19 years ago
irq-rm9000.c	[MIPS] Eleminate interrupt migration helper use.	19 years ago
irq.c	IRQ: Maintain regs pointer globally rather than passing to IRQ handlers	19 years ago
irq_cpu.c	[MIPS] Eleminate interrupt migration helper use.	19 years ago
kspd.c	[MIPS] kpsd and other AP/SP improvements.	19 years ago
linux32.c	[PATCH] VFS: Make filldir_t and struct kstat deal in 64-bit inode numbers	19 years ago
mips-mt.c	[MIPS] MIPS MT: Fix build error.	19 years ago
mips_ksyms.c	Remove obsolete #include <linux/config.h>	19 years ago
module.c	[MIPS] Ignore unresolved weak symbols in modules.	19 years ago
proc.c	Remove obsolete #include <linux/config.h>	19 years ago
process.c	[MIPS] Make unwind_stack() can dig into interrupted context	19 years ago
ptrace.c	Remove obsolete #include <linux/config.h>	19 years ago
ptrace32.c	[MIPS] Unify mips_fpu_soft_struct and mips_fpu_hard_structs.	19 years ago
r4k_fpu.S	Remove obsolete #include <linux/config.h>	19 years ago
r4k_switch.S	Remove obsolete #include <linux/config.h>	19 years ago
r2300_fpu.S	…
r2300_switch.S	Remove obsolete #include <linux/config.h>	19 years ago
r6000_fpu.S	…
reset.c	[MIPS] Rename _machine_power_off to pm_power_off so the kernel builds again.	19 years ago
rtlx.c	[PATCH] irq-flags: MIPS: Use the new IRQF_ constants	19 years ago
scall32-o32.S	[MIPS] lockdep: fix TRACE_IRQFLAGS_SUPPORT	19 years ago
scall64-64.S	[MIPS] lockdep: fix TRACE_IRQFLAGS_SUPPORT	19 years ago
scall64-n32.S	[MIPS] lockdep: fix TRACE_IRQFLAGS_SUPPORT	19 years ago
scall64-o32.S	[MIPS] lockdep: fix TRACE_IRQFLAGS_SUPPORT	19 years ago
semaphore.c	Always use ".set mips3" rather than select between "mips2" or "mips3"	20 years ago
setup.c	[MIPS] setup.c: use early_param() for early command line parsing	19 years ago
signal-common.h	Remove obsolete #include <linux/config.h>	19 years ago
signal.c	[MIPS] Avoid double signal restarting.	19 years ago
signal32.c	[MIPS] Avoid double signal restarting.	19 years ago
signal_n32.c	[PATCH] BLOCK: Revert patch to hack around undeclared sigset_t in linux/compat.h	19 years ago
smp-mt.c	[MIPS] MT: Initialise all writable bits in Cause register to zero.	19 years ago
smp.c	[MIPS] Avoid interprocessor function calls.	19 years ago
smtc-asm.S	[MIPS] SMTC Build fix.	19 years ago
smtc-proc.c	[MIPS] MT: Improved multithreading support.	19 years ago
smtc.c	[MIPS] Replace board_timer_setup function pointer by plat_timer_setup.	19 years ago
stacktrace.c	[MIPS] Make unwind_stack() can dig into interrupted context	19 years ago
syscall.c	[PATCH] provide kernel_execve on all architectures	19 years ago
sysirix.c	[PATCH] VFS: Make filldir_t and struct kstat deal in 64-bit inode numbers	19 years ago
time.c	IRQ: Maintain regs pointer globally rather than passing to IRQ handlers	19 years ago
traps.c	[MIPS] Make unwind_stack() can dig into interrupted context	19 years ago
unaligned.c	Remove obsolete #include <linux/config.h>	19 years ago
vmlinux.lds.S	Remove obsolete #include <linux/config.h>	19 years ago
vpe.c	[MIPS] MT: Fix setting of XTC.	19 years ago