From: Michael Schmitz <schmitzmic@gmail.com>
To: Finn Thain <fthain@linux-m68k.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>,
linux-m68k@lists.linux-m68k.org
Subject: Re: [PATCH RFC] m68k: skip kernel premption if interrupts were disabled
Date: Tue, 26 Mar 2024 11:31:57 +1300 [thread overview]
Message-ID: <597ab0b3-ac1d-443c-95f7-4f1bbcccae1f@gmail.com> (raw)
In-Reply-To: <acd34add-27af-24a5-9af5-d40cab71c651@linux-m68k.org>
Hi Finn,
see below (hopefully not whitespace-damaged).
The set_fc warning is specific to 040 but the bad kernel buserror (null
pointer) causing it isn't. But testing on 030 would be a good idea if
you have one with enough RAM. Haven't tried to boot my Falcon with a
preempt enabled kernel yet.
Cheers,
Michael
diff --git a/arch/m68k/mm/motorola.c b/arch/m68k/mm/motorola.c
index 4d4d390a2df2..96cdcacb94ea 100644
--- a/arch/m68k/mm/motorola.c
+++ b/arch/m68k/mm/motorola.c
@@ -15,6 +15,7 @@
#include <linux/mm.h>
#include <linux/swap.h>
#include <linux/kernel.h>
+#include <linux/preempt.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/init.h>
@@ -195,6 +196,8 @@ int free_pointer_table(void *table, int type)
unsigned long page = ptable & PAGE_MASK;
unsigned int mask = 1U << ((ptable - page)/ptable_size(type));
+ preempt_disable();
+
dp = PD_PTABLE(page);
if (PD_MARKBITS (dp) & mask) {
pr_err("saved from last preempt: nr %x sr %lx %x pc %lx
sp %lx\n",
@@ -213,6 +216,7 @@ int free_pointer_table(void *table, int type)
if (type == TABLE_PTE)
pagetable_pte_dtor(virt_to_ptdesc((void *)page));
free_page (page);
+ sched_preempt_enable_no_resched();
return 1;
} else if (ptable_list[type].next != dp) {
/*
@@ -221,6 +225,7 @@ int free_pointer_table(void *table, int type)
*/
list_move(dp, &ptable_list[type]);
}
+ sched_preempt_enable_no_resched();
return 0;
}
On 26/03/24 11:28, Finn Thain wrote:
> On Mon, 25 Mar 2024, Michael Schmitz wrote:
>
>> Unfortunately, when I add preempt_disable()/
>> sched_preempt_enable_noresched() in free_pointer_table(), I don't get
>> that particular panic() anymore,
> I'd like to try that patch. Would you send it please?
>
>> but the bad kernel buserror with the warning from set_fc() that you
>> reported...
> I think those set_fc() calls are confined to 68040 fault handling. Maybe
> we should try running stress tests on a 68030?
next prev parent reply other threads:[~2024-03-25 22:32 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-03-22 1:48 [PATCH RFC] m68k: skip kernel premption if interrupts were disabled Michael Schmitz
[not found] ` <fcabda73-4b16-ee2c-e993-2bfcf392a26a@linux-m68k.org>
[not found] ` <e89bf618-2fa8-7cbd-16ed-d021a9a7f740@gmail.com>
[not found] ` <948c12e4-e85f-a86c-ae95-a1eb03ca026d@gmail.com>
[not found] ` <40928e38-0de7-75a6-d5f7-8c913155da03@linux-m68k.org>
2024-03-23 6:32 ` Michael Schmitz
2024-03-25 6:41 ` Michael Schmitz
2024-03-25 22:28 ` Finn Thain
2024-03-25 22:31 ` Michael Schmitz [this message]
2024-03-26 0:41 ` Finn Thain
2024-03-26 9:58 ` Finn Thain
2024-03-26 19:59 ` Michael Schmitz
2024-03-26 22:03 ` Finn Thain
2024-03-26 22:35 ` Michael Schmitz
2024-03-27 3:50 ` Finn Thain
2024-03-27 6:56 ` Michael Schmitz
2024-03-27 23:29 ` Spinlock debug, was " Finn Thain
[not found] ` <7aee9fd9-1c0e-4874-bb86-e512a7c0caa6@gmail.com>
2024-03-28 2:48 ` Finn Thain
2024-03-28 19:54 ` Michael Schmitz
2024-03-30 2:46 ` Michael Schmitz
2024-03-30 6:23 ` Finn Thain
2024-03-31 6:14 ` Michael Schmitz
2024-03-27 8:38 ` Finn Thain
2024-03-27 22:59 ` Michael Schmitz
2024-03-27 8:22 ` Geert Uytterhoeven
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