x86: corruption check: run the corruption checks from a work queue

Impact: change the implementation of the debug feature

the periodic 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@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/arch/x86/kernel/check.c b/arch/x86/kernel/check.c
index 5056703..55eed17 100644 (file)
--- a/arch/x86/kernel/check.c
+++ b/arch/x86/kernel/check.c
@@ -1,6 +1,7 @@
 #include <linux/module.h>
 #include <linux/sched.h>
-
+#include <linux/kthread.h>
+#include <linux/workqueue.h>
 #include <asm/e820.h>
 #include <asm/proto.h>
 
@@ -108,13 +109,14 @@ void __init setup_bios_corruption_check(void)
        update_e820();
 }
 
-static struct timer_list periodic_check_timer;
 
 void check_for_bios_corruption(void)
 {
        int i;
        int corruption = 0;
 
+       printk("dot\n");
+
        if (!memory_corruption_check)
                return;
 
@@ -135,24 +137,29 @@ 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);
+static DECLARE_DELAYED_WORK(bios_check_work, check_corruption);
+
+static void check_corruption(struct work_struct *dummy)
 {
        check_for_bios_corruption();
-       mod_timer(&periodic_check_timer,
-               round_jiffies(jiffies + corruption_check_period*HZ));
+       schedule_delayed_work(&bios_check_work,
+               round_jiffies_relative(corruption_check_period*HZ)); 
 }
 
-void start_periodic_check_for_corruption(void)
+static 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);
+       /* First time we run the checks right away */
+       schedule_delayed_work(&bios_check_work, 0);
+       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 8396868..5e63775 100644 (file)
--- a/arch/x86/mm/init_32.c
+++ b/arch/x86/mm/init_32.c
@@ -970,8 +970,6 @@ 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 b8e461d..d6ef158 100644 (file)
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -879,8 +879,6 @@ 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 */