From: Christoph Hellwig <hch@lst.de>
To: Anton Blanchard <anton@samba.org>
Cc: linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH 1/7] powerpc: Reduce footprint of irq_stat
Date: Mon, 1 Feb 2010 22:55:04 +0100 [thread overview]
Message-ID: <20100201215504.GA17194@lst.de> (raw)
In-Reply-To: <20100201063023.GT2996@kryten>
On Mon, Feb 01, 2010 at 05:30:23PM +1100, Anton Blanchard wrote:
>
> PowerPC is currently using asm-generic/hardirq.h which statically allocates an
> NR_CPUS irq_stat array. Switch to an arch specific implementation which uses
> per cpu data:
>
> On a kernel with NR_CPUS=1024, this saves quite a lot of memory:
>
> text data bss dec hex filename
> 8767938 2944132 1636796 13348866 cbb002 vmlinux.baseline
> 8767779 2944260 1505724 13217763 c9afe3 vmlinux.irq_cpustat
>
> A saving of around 128kB.
>
> Signed-off-by: Anton Blanchard <anton@samba.org>
> ---
>
> Index: linux-cpumask/arch/powerpc/include/asm/hardirq.h
> ===================================================================
> --- linux-cpumask.orig/arch/powerpc/include/asm/hardirq.h 2010-01-31 22:07:21.037211728 +1100
> +++ linux-cpumask/arch/powerpc/include/asm/hardirq.h 2010-02-01 17:28:56.990963256 +1100
> @@ -1 +1,22 @@
> -#include <asm-generic/hardirq.h>
> +#ifndef _ASM_POWERPC_HARDIRQ_H
> +#define _ASM_POWERPC_HARDIRQ_H
> +
> +#include <linux/threads.h>
> +#include <linux/irq.h>
> +
> +typedef struct {
> + unsigned int __softirq_pending;
> +} ____cacheline_aligned irq_cpustat_t;
No need to bother with an irq_cpustat_t type at all in this case, just
declare a softirq_pending per-cpu variable.
next prev parent reply other threads:[~2010-02-01 22:04 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-02-01 6:30 [PATCH 1/7] powerpc: Reduce footprint of irq_stat Anton Blanchard
2010-02-01 6:32 ` [PATCH 2/7] powerpc: Reduce footprint of xics_ipi_struct Anton Blanchard
2010-02-01 6:33 ` [PATCH 3/7] powerpc: Rework /proc/interrupts Anton Blanchard
2010-02-01 6:33 ` [PATCH 4/7] powerpc: Remove whitespace in irq chip name fields Anton Blanchard
2010-02-01 6:34 ` [PATCH 5/7] powerpc: Add timer, performance monitor and machine check counts to /proc/interrupts Anton Blanchard
2010-02-01 6:34 ` [PATCH 6/7] powerpc: Convert global "BAD" interrupt to per cpu spurious Anton Blanchard
2010-02-01 6:34 ` [PATCH 7/7] powerpc: Increase NR_IRQS Kconfig maximum to 32768 Anton Blanchard
2010-02-01 21:55 ` Christoph Hellwig [this message]
2010-02-01 23:07 ` [PATCH 1/7] powerpc: Reduce footprint of irq_stat Benjamin Herrenschmidt
2010-02-02 8:19 ` Christoph Hellwig
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