From: michael <michael@evidence•eu.com>
To: Rafael Beims <rbeims@gmail•com>
Cc: linuxppc-dev@ozlabs•org
Subject: Re: mpc880 linux-2.6.32 slow running processes
Date: Wed, 05 Jan 2011 19:23:33 +0100 [thread overview]
Message-ID: <4D24B725.2020300@evidence.eu.com> (raw)
In-Reply-To: <AANLkTin5XTnDEu1BJUOeF0UWtfEpotW5Bq__i8g6U05h@mail.gmail.com>
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Hi
On 01/05/2011 07:09 PM, Rafael Beims wrote:
> Hello all,
> I'm working with an MPC880 board that is supposed to run linux-2.6.32. After
> some work, I could get the kernel up and running, mounting a rootfs via
> NFS.
> The problem that I'm facing now is that when I try to run any process (may
> be an ls, cat, or whatever), the response of the process is *very* slow
> (something like 10 to 20 seconds for a ls).
> Monitoring the network packets, I can see that the nfs protocol is exchanged
> just fine, but at some time it simply stops, starting again with a request
> from the board several seconds later.
> I'm thinking that the processor is running (something, I don't know what)
> for all this time before I can see requests coming from the board again. I
> pinged the board from the PC and during all this I can see the packets being
> answered.
>
Can you try this patch?
> My question to all is, did anyone see something like this already? Besides
> that, what is the status of the linux kernel support for the 8xx platform?
> Is it being actively tested / used today? I ask this because it seems that
> all the information on the internet very aged (forum discussions from 2005
> and below mostly).
>
> Is there something that I can do to try to narrow the cause of the problem?
>
> Anyway, any help would be truly appreciated. Please excuse me if this is not
> the right place to ask this too.
>
> Thanks and best regards,
> Rafael Beims
> rbeims@gmail•com
> (41) 8873-7565
> "What I hear, I forget. What I see, I remember. And what I do, I
> understand."
> - Chinese Proverb
>
>
>
> _______________________________________________
> Linuxppc-dev mailing list
> Linuxppc-dev@lists•ozlabs.org
> https://lists.ozlabs.org/listinfo/linuxppc-dev
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diff --git a/arch/powerpc/include/asm/pte-8xx.h b/arch/powerpc/include/asm/pte-8xx.h
index dd5ea95..cb67076 100644
--- a/arch/powerpc/include/asm/pte-8xx.h
+++ b/arch/powerpc/include/asm/pte-8xx.h
@@ -32,7 +32,7 @@
#define _PAGE_FILE 0x0002 /* when !present: nonlinear file mapping */
#define _PAGE_NO_CACHE 0x0002 /* I: cache inhibit */
#define _PAGE_SHARED 0x0004 /* No ASID (context) compare */
-#define _PAGE_SPECIAL 0x0008 /* SW entry, forced to 0 by the TLB miss */
+#define _PAGE_SPECIAL 0x0000 /* SW entry, forced to 0 by the TLB miss */
/* These five software bits must be masked out when the entry is loaded
* into the TLB.
diff --git a/arch/powerpc/include/asm/pte-common.h b/arch/powerpc/include/asm/pte-common.h
index f2b3701..3b88376 100644
--- a/arch/powerpc/include/asm/pte-common.h
+++ b/arch/powerpc/include/asm/pte-common.h
@@ -176,5 +176,7 @@ extern unsigned long bad_call_to_PMD_PAGE_SIZE(void);
#define HAVE_PAGE_AGP
/* Advertise support for _PAGE_SPECIAL */
+#if _PAGE_SPECIAL != 0
#define __HAVE_ARCH_PTE_SPECIAL
+#endif
diff --git a/arch/powerpc/mm/pgtable.c b/arch/powerpc/mm/pgtable.c
index 5304093..1da03a8 100644
--- a/arch/powerpc/mm/pgtable.c
+++ b/arch/powerpc/mm/pgtable.c
@@ -173,21 +173,29 @@ static pte_t set_pte_filter(pte_t pte, unsigned long addr)
pte = __pte(pte_val(pte) & ~_PAGE_HPTEFLAGS);
if (pte_looks_normal(pte) && !(cpu_has_feature(CPU_FTR_COHERENT_ICACHE) ||
cpu_has_feature(CPU_FTR_NOEXECUTE))) {
- struct page *pg = maybe_pte_to_page(pte);
- if (!pg)
+ unsigned long pfn = pte_pfn(pte);
+ struct page *pg;
+
+ if (unlikely(!pfn_valid(pfn)))
return pte;
- if (!test_bit(PG_arch_1, &pg->flags)) {
+
+ pg = pfn_to_page(pfn);
#ifdef CONFIG_8xx
- /* On 8xx, cache control instructions (particularly
- * "dcbst" from flush_dcache_icache) fault as write
- * operation if there is an unpopulated TLB entry
- * for the address in question. To workaround that,
- * we invalidate the TLB here, thus avoiding dcbst
- * misbehaviour.
- */
- /* 8xx doesn't care about PID, size or ind args */
- _tlbil_va(addr, 0, 0, 0);
+ /* On 8xx, cache control instructions (particularly
+ * "dcbst" from flush_dcache_icache) fault as write
+ * operation if there is an unpopulated TLB entry
+ * for the address in question. To workaround that,
+ * we invalidate the TLB here, thus avoiding dcbst
+ * misbehaviour.
+ */
+ /* 8xx doesn't care about PID, size or ind args */
+ _tlbil_va(addr, 0, 0, 0);
#endif /* CONFIG_8xx */
+
+ if (!pg)
+ return pte;
+
+ if (!PageReserved(pg) && !test_bit(PG_arch_1, &pg->flags)) {
flush_dcache_icache_page(pg);
set_bit(PG_arch_1, &pg->flags);
}
next prev parent reply other threads:[~2011-01-05 19:23 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-01-05 18:09 mpc880 linux-2.6.32 slow running processes Rafael Beims
2011-01-05 18:23 ` michael [this message]
[not found] ` <AANLkTi=uvunJ-ZFVGHZZExgBaNL9Sh0uZ3OiiCrcPnx=@mail.gmail.com>
2011-01-05 18:45 ` Fwd: " Rafael Beims
2011-01-05 19:13 ` michael
2011-01-05 23:42 ` Scott Wood
2011-01-06 12:52 ` michael
2011-01-06 16:52 ` Joakim Tjernlund
2011-01-07 10:00 ` Rafael Beims
2011-01-08 21:43 ` Joakim Tjernlund
2011-01-10 16:35 ` Rafael Beims
2011-01-10 16:55 ` Joakim Tjernlund
2011-01-11 16:00 ` Joakim Tjernlund
2011-01-21 6:53 ` Heiko Schocher
2011-01-22 9:50 ` Joakim Tjernlund
2011-01-05 18:35 ` Wolfgang Denk
2011-01-05 18:50 ` Rafael Beims
2011-01-05 19:22 ` michael
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