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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)		19 years ago
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Kconfig	…
Makefile	…
ahci.c	IRQ: Maintain regs pointer globally rather than passing to IRQ handlers	19 years ago
ata_generic.c	[libata] Don't use old-EH ->eng_timeout() hook when not needed	19 years ago
ata_piix.c	…
libata-core.c	IRQ: Maintain regs pointer globally rather than passing to IRQ handlers	19 years ago
libata-eh.c	…
libata-scsi.c	[PATCH] libata: turn off NCQ if queue depth is adjusted to 1	19 years ago
libata-sff.c	[libata] init probe_ent->private_data in a common location	19 years ago
libata.h	…
pata_ali.c	[PATCH] pata: teach ali about rev C8, keep pcmcia driver in sync	19 years ago
pata_amd.c	[libata] PCI ID table cleanup in various drivers	19 years ago
pata_artop.c	[libata] pata_artop: kill gcc warning	19 years ago
pata_atiixp.c	[libata] PCI ID table cleanup in various drivers	19 years ago
pata_cmd64x.c	[libata] PCI ID table cleanup in various drivers	19 years ago
pata_cs5520.c	[libata] PCI ID table cleanup in various drivers	19 years ago
pata_cs5530.c	[libata] PCI ID table cleanup in various drivers	19 years ago
pata_cs5535.c	[libata] PCI ID table cleanup in various drivers	19 years ago
pata_cypress.c	[libata] PCI ID table cleanup in various drivers	19 years ago
pata_efar.c	[libata] PCI ID table cleanup in various drivers	19 years ago
pata_hpt3x2n.c	[libata] PCI ID table cleanup in various drivers	19 years ago
pata_hpt3x3.c	[libata] PCI ID table cleanup in various drivers	19 years ago
pata_hpt37x.c	[libata] PCI ID table cleanup in various drivers	19 years ago
pata_hpt366.c	Merge branch 'upstream-linus' of master.kernel.org:/pub/scm/linux/kernel/git/jgarzik/libata-dev	19 years ago
pata_isapnp.c	[libata] Don't use old-EH ->eng_timeout() hook when not needed	19 years ago
pata_it821x.c	[libata] PCI ID table cleanup in various drivers	19 years ago
pata_jmicron.c	[libata] PCI ID table cleanup in various drivers	19 years ago
pata_legacy.c	[libata] Don't use old-EH ->eng_timeout() hook when not needed	19 years ago
pata_mpiix.c	[libata] PCI ID table cleanup in various drivers	19 years ago
pata_netcell.c	[libata] PCI ID table cleanup in various drivers	19 years ago
pata_ns87410.c	[libata] PCI ID table cleanup in various drivers	19 years ago
pata_oldpiix.c	[libata] PCI ID table cleanup in various drivers	19 years ago
pata_opti.c	[libata] PCI ID table cleanup in various drivers	19 years ago
pata_optidma.c	[libata] PCI ID table cleanup in various drivers	19 years ago
pata_pcmcia.c	[PATCH] pata: teach ali about rev C8, keep pcmcia driver in sync	19 years ago
pata_pdc202xx_old.c	[libata] PCI ID table cleanup in various drivers	19 years ago
pata_pdc2027x.c	[libata] PCI ID table cleanup in various drivers	19 years ago
pata_qdi.c	[libata] Don't use old-EH ->eng_timeout() hook when not needed	19 years ago
pata_radisys.c	[libata] PCI ID table cleanup in various drivers	19 years ago
pata_rz1000.c	[libata] PCI ID table cleanup in various drivers	19 years ago
pata_sc1200.c	[libata] PCI ID table cleanup in various drivers	19 years ago
pata_serverworks.c	[libata] PCI ID table cleanup in various drivers	19 years ago
pata_sil680.c	[libata] PCI ID table cleanup in various drivers	19 years ago
pata_sis.c	[libata] PCI ID table cleanup in various drivers	19 years ago
pata_sl82c105.c	[libata] PCI ID table cleanup in various drivers	19 years ago
pata_triflex.c	[libata] PCI ID table cleanup in various drivers	19 years ago
pata_via.c	[libata] PCI ID table cleanup in various drivers	19 years ago
pdc_adma.c	IRQ: Maintain regs pointer globally rather than passing to IRQ handlers	19 years ago
sata_mv.c	IRQ: Maintain regs pointer globally rather than passing to IRQ handlers	19 years ago
sata_nv.c	IRQ: Maintain regs pointer globally rather than passing to IRQ handlers	19 years ago
sata_promise.c	IRQ: Maintain regs pointer globally rather than passing to IRQ handlers	19 years ago
sata_promise.h	…
sata_qstor.c	IRQ: Maintain regs pointer globally rather than passing to IRQ handlers	19 years ago
sata_sil.c	IRQ: Maintain regs pointer globally rather than passing to IRQ handlers	19 years ago
sata_sil24.c	IRQ: Maintain regs pointer globally rather than passing to IRQ handlers	19 years ago
sata_sis.c	[libata] PCI ID table cleanup in various drivers	19 years ago
sata_svw.c	[libata] PCI ID table cleanup in various drivers	19 years ago
sata_sx4.c	IRQ: Maintain regs pointer globally rather than passing to IRQ handlers	19 years ago
sata_uli.c	[libata] PCI ID table cleanup in various drivers	19 years ago
sata_via.c	[libata] PCI ID table cleanup in various drivers	19 years ago
sata_vsc.c	IRQ: Maintain regs pointer globally rather than passing to IRQ handlers	19 years ago