Messages in this thread | | | Date | Thu, 14 Aug 2008 12:01:49 -0700 | From | "Yinghai Lu" <> | Subject | Re: [PATCH 00/53] dyn_array/nr_irqs/sparse_irq support v10 |
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On Thu, Aug 14, 2008 at 6:26 AM, Ingo Molnar <mingo@elte.hu> wrote: > > (lkml Cc:-ed) > > * Yinghai Lu <yhlu.kernel@gmail.com> wrote: > >> v10: make the x86 32 bit support sparse_irq too. >> also make remove irqbalance in kernel for 32 bit >> and make 32 bit support per_cpu vector. so start merging or io_apic_xx.c >> >> 01-03 is some fix for current tree >> 04: is revert for one patch hide in sched/ and tip/master >> >> based on tip/master >> >> to do: >> merge io_apic_xx.c > > ok, i've created a new tip/irq/sparseirq topic branch for this. > > Could you please send future updates against: > > git-checkout tip/master > git-merge tip/irq/sparseirq > > Not yet integrated into tip/master, i've still got some other backlog. > > A couple of observations about the general structure of the sparse irqs > code: > > - the new APIs should probably live in mm/bootmem.c not in init/main.c, > and in bootmem.h. Also, it should be outlined clearly why this new API > is needed as a wrapper ontop of existing bootmem mechanisms.
move pre_alloc_dyn_array, per_cpu_dyn_array_size, per_cpu_alloc_dyn_array to mm/bootmem.c?
> > - the #ifdef complications, while fine for migration, should be > eliminated. Could we introduce some compatible form for the > definition/allocation APIs that work even if an architecture still > uses a flat irq array? That would remove most of the uglinesses. # git grep CONFIG_HAVE_DYN_ARRAY | wc -l 9
#git grep CONFIG_HAVE_SPARSE_IRQ | wc -l 39
arch/x86/kernel/io_apic_32.c:#ifdef CONFIG_HAVE_SPARSE_IRQ_DEBUG arch/x86/kernel/io_apic_32.c:#ifndef CONFIG_HAVE_SPARSE_IRQ arch/x86/kernel/io_apic_64.c:#ifdef CONFIG_HAVE_SPARSE_IRQ_DEBUG arch/x86/kernel/io_apic_64.c:#ifndef CONFIG_HAVE_SPARSE_IRQ arch/x86/kernel/irq_32.c:#ifdef CONFIG_HAVE_SPARSE_IRQ arch/x86/kernel/irq_64.c:#ifdef CONFIG_HAVE_SPARSE_IRQ drivers/char/random.c:#ifndef CONFIG_HAVE_SPARSE_IRQ drivers/char/random.c:#ifndef CONFIG_HAVE_SPARSE_IRQ drivers/pci/intr_remapping.c:#ifdef CONFIG_HAVE_SPARSE_IRQ drivers/pci/intr_remapping.c:#else /* !CONFIG_HAVE_SPARSE_IRQ */ drivers/pci/intr_remapping.c:#ifndef CONFIG_HAVE_SPARSE_IRQ fs/proc/proc_misc.c:#ifdef CONFIG_HAVE_SPARSE_IRQ fs/proc/proc_misc.c:#ifdef CONFIG_HAVE_SPARSE_IRQ fs/proc/proc_misc.c:#ifdef CONFIG_HAVE_SPARSE_IRQ include/linux/irq.h:#ifdef CONFIG_HAVE_SPARSE_IRQ include/linux/irq.h:#ifdef CONFIG_HAVE_SPARSE_IRQ include/linux/irq.h:#ifdef CONFIG_HAVE_SPARSE_IRQ include/linux/irq.h:#ifdef CONFIG_HAVE_SPARSE_IRQ include/linux/irq.h:#if defined(CONFIG_INTR_REMAP) && defined(CONFIG_HAVE_SPARSE_IRQ) include/linux/irq.h:#ifndef CONFIG_HAVE_SPARSE_IRQ kernel/irq/chip.c:#ifdef CONFIG_HAVE_SPARSE_IRQ kernel/irq/chip.c:#ifdef CONFIG_HAVE_SPARSE_IRQ kernel/irq/chip.c:#ifdef CONFIG_HAVE_SPARSE_IRQ kernel/irq/chip.c:#ifdef CONFIG_HAVE_SPARSE_IRQ kernel/irq/chip.c:#ifdef CONFIG_HAVE_SPARSE_IRQ kernel/irq/handle.c:#ifdef CONFIG_HAVE_SPARSE_IRQ kernel/irq/handle.c:#ifndef CONFIG_HAVE_SPARSE_IRQ kernel/irq/handle.c:#ifdef CONFIG_HAVE_SPARSE_IRQ kernel/irq/handle.c:#ifdef CONFIG_HAVE_SPARSE_IRQ kernel/irq/handle.c:#ifdef CONFIG_HAVE_SPARSE_IRQ_DEBUG kernel/irq/handle.c:#ifndef CONFIG_HAVE_SPARSE_IRQ kernel/irq/handle.c:#ifdef CONFIG_HAVE_SPARSE_IRQ kernel/irq/handle.c:#ifdef CONFIG_HAVE_SPARSE_IRQ kernel/irq/handle.c:#ifdef CONFIG_HAVE_SPARSE_IRQ kernel/irq/handle.c:#ifdef CONFIG_HAVE_SPARSE_IRQ kernel/irq/handle.c:#ifdef CONFIG_HAVE_SPARSE_IRQ kernel/irq/manage.c:#ifdef CONFIG_HAVE_SPARSE_IRQ kernel/irq/manage.c:#ifdef CONFIG_HAVE_SPARSE_IRQ kernel/irq/migration.c:#ifdef CONFIG_HAVE_SPARSE_IRQ
because try to avoid more api to be changed to take irq_desc as parameter.
> > - some of the irq < 16 checks in x86 look a bit ugly, can we do anything > about them?
is_legacy_irq(irq) ? or legacy_irq(irq)?
> > - i think as a final-ish commit we should just remove the dyn-array > define and make all architectures use this facility. You converted > most of them - how many are still missing? Sparse-irq is more > intrusive so that should probably stay a Kconfig knob.
so when config_sparse_irq is not selected, need to use dyn_array to allocate irq_desc and irq_cfg, or just static array?
> > - there was one aspect of NR_IRQS that was nice and useful: it acted as > a sanity check against BIOS bugs and driver bugs that pass in some > irrealistically high irq number. Now we'll just try to allocate some > really high IRQ and accept it. I _think_ there should be a single, > simple 'absolute maximum IRQ number' define which should set the > maximum possible IRQ number. Lets call it NR_IRQS_MAX or so, and set > it to NR_CPUS*NR_IO_APICS*224 or so?
when sparse_irq is used, irq is [0, -1U] driver could be irq_desc(irq) to check if irq is valid or not. and use irq_desc_with_new(new) to get a new one.
when generic_hardirqs is not used (s390, m68k, sparc), we need to create some stubs in linux/interrupt.h for them
> > - i'm a bit worried about linecount increase in general: > > 247 files changed, 3671 insertions(+), 2052 deletions(-) > > could we work on reducing that somewhat? The new infrastructure bits > in mm/* and kernel/irq/* will be unavoidable, what we should > concentrate on is to make usage of the new facility just as > straightforward, easy and compact as the old irq_desc[] usages. before that we could use get_irq_desc() and get_irq_desc_without_new() and according to eric, i changed that to irq_desc_with_new and irq_desc().
so the array irq_desc[] need to be changed to irq_descX[] ( or *irq_desc to *irq_descX for dyn_array) > > A worst-case example is drivers/char/random.c: the > CONFIG_HAVE_SPARSE_IRQ and CONFIG_HAVE_DYN_ARRAY #ifdef jungle is not > acceptable. I think the best way out is to convert the whole kernel to > the new facilities (as safely as possible, without breaking other > architectures), and making sure that the end result is easy to > understand and intuitive.
# grep CONFIG_HAVE_ drivers/char/random.c #ifndef CONFIG_HAVE_SPARSE_IRQ #ifdef CONFIG_HAVE_DYN_ARRAY #ifndef CONFIG_HAVE_SPARSE_IRQ
just want to make other arch is untouched.
> > so i dont mind the current code as long as the extra complications are > temporary during a safe conversion - but we should work on eliminating > all those complications before thinking about upstream merging. > > Ingo > > --------------------> > the irq/sparseirq git tree can be picked up from: > > git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip.git irq/sparseirq >
Thanks
Yinghai Lu
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