From: Benjamin Herrenschmidt <benh@kernel•crashing.org>
To: Joakim Tjernlund <Joakim.Tjernlund@transmode•se>
Cc: linuxppc-dev@ozlabs•org
Subject: Re: [PATCH 2/4] 8xx: Avoid testing for kernel space in ITLB Miss.
Date: Wed, 17 Mar 2010 08:19:36 +1100 [thread overview]
Message-ID: <1268774376.2335.130.camel@pasglop> (raw)
In-Reply-To: <1267172983-28721-3-git-send-email-Joakim.Tjernlund@transmode.se>
On Fri, 2010-02-26 at 09:29 +0100, Joakim Tjernlund wrote:
> +#ifdef CONFIG_MODULES
> + /* Only modules will cause ITLB Misses as we always
> + * pin the first 8MB of kernel memory */
> andi. r11, r10, 0x0800 /* Address >= 0x80000000 */
> beq 3f
> lis r11, swapper_pg_dir@h
> ori r11, r11, swapper_pg_dir@l
> rlwimi r10, r11, 0, 2, 19
> 3:
> +#endif
You can optimize that further I think...
You can probably just remove the code above, and add something to
do_page_fault() that lazily copies the kernel PGD entries from
swapper_pg_dir to the app pgdir. (You can even pre-fill that when
creating a new mm).
Cheers,
Ben.
next prev parent reply other threads:[~2010-03-16 21:19 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-02-26 8:29 [PATCH 0/4] 8xx: Optimize TLB Miss code Joakim Tjernlund
2010-02-26 8:29 ` [PATCH 1/4] 8xx: Optimze TLB Miss handlers Joakim Tjernlund
2010-02-26 8:29 ` [PATCH 2/4] 8xx: Avoid testing for kernel space in ITLB Miss Joakim Tjernlund
2010-02-26 8:29 ` [PATCH 3/4] 8xx: Don't touch ACCESSED when no SWAP Joakim Tjernlund
2010-02-26 8:29 ` [PATCH 4/4] 8xx: Use SPRG2 and DAR registers to stash r11 and cr Joakim Tjernlund
2010-03-16 21:20 ` [PATCH 3/4] 8xx: Don't touch ACCESSED when no SWAP Benjamin Herrenschmidt
2010-03-17 7:40 ` Joakim Tjernlund
2010-03-16 21:19 ` Benjamin Herrenschmidt [this message]
2010-03-17 7:35 ` [PATCH 2/4] 8xx: Avoid testing for kernel space in ITLB Miss Joakim Tjernlund
2010-02-26 19:50 ` [PATCH 1/4] 8xx: Optimze TLB Miss handlers Scott Wood
2010-02-27 15:23 ` Joakim Tjernlund
2010-02-26 20:10 ` Kumar Gala
2010-02-27 15:25 ` Joakim Tjernlund
-- strict thread matches above, loose matches on Subject: below --
2010-03-02 15:37 [PATCH 0/4] 8xx: Optimize TLB Miss code Joakim Tjernlund
2010-03-02 15:37 ` [PATCH 1/4] 8xx: Optimze TLB Miss handlers Joakim Tjernlund
2010-03-02 15:37 ` [PATCH 2/4] 8xx: Avoid testing for kernel space in ITLB Miss Joakim Tjernlund
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