Re: [PATCH 2/2] corruption check: run the corruption checks from awork queue

From: Arjan van de Ven
Date: Mon Sep 22 2008 - 19:24:31 EST


eh a stray debug // snuck in; update attached


From: Arjan van de Ven <arjan@xxxxxxxxxxxxxxx>
Date: Mon, 22 Sep 2008 13:42:15 -0700
Subject: [PATCH] corruption check: run the corruption checks from a work queue

the corruption checks are better off run from a work queue; there's nothing
time critical about them and this way the amount of interrupt-context work
is reduced.

Signed-off-by: Arjan van de Ven <arjan@xxxxxxxxxxxxxxx>
---
arch/x86/kernel/corruptioncheck.c | 21 +++++++++++++++++----
arch/x86/mm/init_32.c | 2 --
arch/x86/mm/init_64.c | 2 --
include/linux/kernel.h | 2 +-
4 files changed, 18 insertions(+), 9 deletions(-)

diff --git a/arch/x86/kernel/corruptioncheck.c b/arch/x86/kernel/corruptioncheck.c
index a7e80ed..cd89219 100644
--- a/arch/x86/kernel/corruptioncheck.c
+++ b/arch/x86/kernel/corruptioncheck.c
@@ -1,5 +1,6 @@
#include <linux/module.h>
#include <linux/sched.h>
+#include <linux/kthread.h>

#include <asm/e820.h>
#include <asm/proto.h>
@@ -135,22 +136,34 @@ void check_for_bios_corruption(void)
WARN(corruption, KERN_ERR "Memory corruption detected in low memory\n");
}

-static void periodic_check_for_corruption(unsigned long data)
+static void check_corruption(struct work_struct *dummy)
{
check_for_bios_corruption();
+}
+
+static void periodic_check_for_corruption(unsigned long data)
+{
+ static DECLARE_WORK(corruptioncheck_work, check_corruption);
+ schedule_work(&corruptioncheck_work);
mod_timer(&periodic_check_timer, round_jiffies(jiffies + corruption_check_period*HZ));
}

-void start_periodic_check_for_corruption(void)
+
+
+int start_periodic_check_for_corruption(void)
{
if (!memory_corruption_check || corruption_check_period == 0)
- return;
+ return 0;

printk(KERN_INFO "Scanning for low memory corruption every %d seconds\n",
corruption_check_period);

init_timer(&periodic_check_timer);
periodic_check_timer.function = &periodic_check_for_corruption;
- periodic_check_for_corruption(0);
+ mod_timer(&periodic_check_timer, round_jiffies(jiffies + corruption_check_period*HZ));
+
+ return 0;
}
+
+module_init(start_periodic_check_for_corruption);
#endif
diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c
index b4c3a92..16ea9d0 100644
--- a/arch/x86/mm/init_32.c
+++ b/arch/x86/mm/init_32.c
@@ -905,8 +905,6 @@ void __init mem_init(void)
int codesize, reservedpages, datasize, initsize;
int tmp;

- start_periodic_check_for_corruption();
-
#ifdef CONFIG_FLATMEM
BUG_ON(!mem_map);
#endif
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index b565721..b65492e 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -822,8 +822,6 @@ void __init mem_init(void)
{
long codesize, reservedpages, datasize, initsize;

- start_periodic_check_for_corruption();
-
pci_iommu_alloc();

/* clear_bss() already clear the empty_zero_page */
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index a5afee2..01085d2 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -260,7 +260,7 @@ extern int root_mountflags;
* able to scatter it around anywhere in the kernel.
*/
void check_for_bios_corruption(void);
-void start_periodic_check_for_corruption(void);
+int start_periodic_check_for_corruption(void);
#else
static inline void check_for_bios_corruption(void)
{
--
1.5.5.1



--
Arjan van de Ven Intel Open Source Technology Centre
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