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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)		18 years ago
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aty	IRQ: Maintain regs pointer globally rather than passing to IRQ handlers	18 years ago
backlight	Merge branch 'devel' of master.kernel.org:/home/rmk/linux-2.6-arm	19 years ago
console	IRQ: Maintain regs pointer globally rather than passing to IRQ handlers	18 years ago
geode	[PATCH] vt: Remove VT-specific declarations and definitions from tty.h	19 years ago
i810	[PATCH] i810fb: Honor the return value of pci_enable_device	19 years ago
intelfb	IRQ: Maintain regs pointer globally rather than passing to IRQ handlers	18 years ago
kyro	[PATCH] vt: Remove VT-specific declarations and definitions from tty.h	19 years ago
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matrox	IRQ: Maintain regs pointer globally rather than passing to IRQ handlers	18 years ago
mbx	[PATCH] mbxfb: Fix framebuffer size smaller than requested	19 years ago
nvidia	[PATCH] nvidia fbdev: fix powerpc xmon scribbles	19 years ago
pnx4008	…
riva	[PATCH] fbdev: riva warning fix	18 years ago
savage	[PATCH] savagefb: Use generic DDC reading	19 years ago
sis	[PATCH] drivers/video/sis/sis_main.h Removal of old code	19 years ago
68328fb.c	[PATCH] vt: Remove VT-specific declarations and definitions from tty.h	19 years ago
Kconfig	Still more typo fixes	18 years ago
Makefile	[PATCH] fbdev: Add generic ddc read functionality	19 years ago
S3triofb.c	Merge branch 'merge'	19 years ago
acornfb.c	…
acornfb.h	…
amba-clcd.c	…
amifb.c	IRQ: Maintain regs pointer globally rather than passing to IRQ handlers	18 years ago
arcfb.c	IRQ: Maintain regs pointer globally rather than passing to IRQ handlers	18 years ago
asiliantfb.c	[PATCH] vt: Remove VT-specific declarations and definitions from tty.h	19 years ago
atafb.c	IRQ: Maintain regs pointer globally rather than passing to IRQ handlers	18 years ago
au1100fb.c	[PATCH] au1100fb: Add option to enable/disable the cursor	19 years ago
au1100fb.h	…
au1200fb.c	IRQ: Maintain regs pointer globally rather than passing to IRQ handlers	18 years ago
au1200fb.h	…
bt431.h	…
bt455.h	…
bw2.c	…
c2p.c	…
c2p.h	…
cfbcopyarea.c	…
cfbfillrect.c	…
cfbimgblt.c	…
cg3.c	…
cg6.c	…
cg14.c	…
chipsfb.c	[PATCH] powermac: Combined fixes for backlight code	19 years ago
cirrusfb.c	[PATCH] vt: Remove VT-specific declarations and definitions from tty.h	19 years ago
clps711xfb.c	…
controlfb.c	[PATCH] vt: Remove VT-specific declarations and definitions from tty.h	19 years ago
controlfb.h	…
cyber2000fb.c	[PATCH] vt: Remove VT-specific declarations and definitions from tty.h	19 years ago
cyber2000fb.h	…
cyberfb.c	[PATCH] vt: Remove VT-specific declarations and definitions from tty.h	19 years ago
cyberfb.h	…
cyblafb.c	…
dnfb.c	[PATCH] vt: Remove VT-specific declarations and definitions from tty.h	19 years ago
edid.h	…
epson1355fb.c	[PATCH] vt: Remove VT-specific declarations and definitions from tty.h	19 years ago
fb_ddc.c	[PATCH] fbdev: Add generic ddc read functionality	19 years ago
fb_notify.c	[PATCH] fbdev: statically link the framebuffer notification functions	19 years ago
fbcmap.c	[PATCH] vt: Remove VT-specific declarations and definitions from tty.h	19 years ago
fbcvt.c	…
fbmem.c	[PATCH] fbdev: correct buffer size limit in fbmem_read_proc()	19 years ago
fbmon.c	[PATCH] vt: Remove VT-specific declarations and definitions from tty.h	19 years ago
fbsysfs.c	[PATCH] fbdev: Honor the return value of device_create_file	19 years ago
ffb.c	…
fm2fb.c	…
g364fb.c	[PATCH] vt: Remove VT-specific declarations and definitions from tty.h	19 years ago
gbefb.c	…
hgafb.c	[PATCH] vt: Remove VT-specific declarations and definitions from tty.h	19 years ago
hitfb.c	video: hitfb suspend/resume and updates.	19 years ago
hpfb.c	[PATCH] vt: Remove VT-specific declarations and definitions from tty.h	19 years ago
igafb.c	[PATCH] vt: Remove VT-specific declarations and definitions from tty.h	19 years ago
imacfb.c	[PATCH] x86: Fix dmi detection of MacBookPro and iMac	19 years ago
imsttfb.c	[PATCH] vt: Remove VT-specific declarations and definitions from tty.h	19 years ago
imxfb.c	…
imxfb.h	…
leo.c	…
macfb.c	[PATCH] vt: Remove VT-specific declarations and definitions from tty.h	19 years ago
macmodes.c	…
macmodes.h	…
maxinefb.c	[PATCH] vt: Remove VT-specific declarations and definitions from tty.h	19 years ago
modedb.c	[PATCH] vt: Remove VT-specific declarations and definitions from tty.h	19 years ago
neofb.c	[PATCH] vt: Remove VT-specific declarations and definitions from tty.h	19 years ago
offb.c	Merge branch 'merge'	19 years ago
p9100.c	…
platinumfb.c	[PATCH] vt: Remove VT-specific declarations and definitions from tty.h	19 years ago
platinumfb.h	…
pm2fb.c	[PATCH] vt: Remove VT-specific declarations and definitions from tty.h	19 years ago
pm3fb.c	[PATCH] vt: Remove VT-specific declarations and definitions from tty.h	19 years ago
pmag-aa-fb.c	[PATCH] vt: Remove VT-specific declarations and definitions from tty.h	19 years ago
pmag-ba-fb.c	…
pmagb-b-fb.c	…
pvr2fb.c	IRQ: Maintain regs pointer globally rather than passing to IRQ handlers	18 years ago
pxafb.c	IRQ: Maintain regs pointer globally rather than passing to IRQ handlers	18 years ago
pxafb.h	[ARM] 3848/1: pxafb: Add option of fixing video modes and spitz QVGA mode support	19 years ago
q40fb.c	[PATCH] vt: Remove VT-specific declarations and definitions from tty.h	19 years ago
retz3fb.c	[PATCH] vt: Remove VT-specific declarations and definitions from tty.h	19 years ago
retz3fb.h	…
s1d13xxxfb.c	…
s3c2410fb.c	IRQ: Maintain regs pointer globally rather than passing to IRQ handlers	18 years ago
s3c2410fb.h	fix file specification in comments	18 years ago
sa1100fb.c	IRQ: Maintain regs pointer globally rather than passing to IRQ handlers	18 years ago
sa1100fb.h	…
sbuslib.c	…
sbuslib.h	…
sgivwfb.c	…
skeletonfb.c	[PATCH] vt: Remove VT-specific declarations and definitions from tty.h	19 years ago
sstfb.c	[PATCH] sstfb: cleanups	19 years ago
sticore.h	…
stifb.c	…
sun3fb.c	[PATCH] vt: Remove VT-specific declarations and definitions from tty.h	19 years ago
tcx.c	…
tdfxfb.c	[PATCH] vt: Remove VT-specific declarations and definitions from tty.h	19 years ago
tgafb.c	[PATCH] vt: Remove VT-specific declarations and definitions from tty.h	19 years ago
tridentfb.c	…
tx3912fb.c	[PATCH] vt: Remove VT-specific declarations and definitions from tty.h	19 years ago
valkyriefb.c	[PATCH] vt: Remove VT-specific declarations and definitions from tty.h	19 years ago
valkyriefb.h	…
vesafb.c	[PATCH] vt: Remove VT-specific declarations and definitions from tty.h	19 years ago
vfb.c	[PATCH] vt: Remove VT-specific declarations and definitions from tty.h	19 years ago
vga16fb.c	[PATCH] vt: Remove VT-specific declarations and definitions from tty.h	19 years ago
vgastate.c	…
virgefb.c	[PATCH] vt: Remove VT-specific declarations and definitions from tty.h	19 years ago
virgefb.h	…
w100fb.c	…
w100fb.h	…