Add back these constants, but this time make sure we won't divide by 0 or

Tue Oct 11 22:40:24 2005  Soeren Sandmann  <sandmann@redhat.com>

        * module/sysprof-module.c (SAMPLES_PER_SECOND): Add back these
        constants, but this time make sure we won't divide by 0 or
        anything like that.

diff --git a/ChangeLog b/ChangeLog
index 965488a..d7cb743 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Tue Oct 11 22:40:24 2005  Soeren Sandmann  <sandmann@redhat.com>
+
+       * module/sysprof-module.c (SAMPLES_PER_SECOND): Add back these
+       constants, but this time make sure we won't divide by 0 or
+       anything like that.
+
 Mon Oct 10 22:49:03 2005  Soeren Sandmann  <sandmann@redhat.com>
 
        * module/sysprof-module.c: Delete lots of commented-out code.

diff --git a/module/sysprof-module.c b/module/sysprof-module.c
index 5a26749..24529fb 100644 (file)
--- a/module/sysprof-module.c
+++ b/module/sysprof-module.c
@@ -70,6 +70,9 @@ DECLARE_WAIT_QUEUE_HEAD (wait_for_exit);
 # error Sysprof only supports the i386 and x86-64 architectures
 #endif
 
+#define SAMPLES_PER_SECOND 250
+#define INTERVAL ((HZ <= SAMPLES_PER_SECOND)? 1 : (HZ / SAMPLES_PER_SECOND))
+
 typedef struct userspace_reader userspace_reader;
 struct userspace_reader
 {
@@ -217,8 +220,7 @@ static int pages_present(StackFrame * head)
 }
 #endif /* CONFIG_X86_4G */
 
-static int
-timer_notify (struct pt_regs *regs)
+static int timer_notify (struct pt_regs *regs)
 {
 #ifdef CONFIG_HIGHMEM
 #  define START_OF_STACK 0xFF000000
@@ -231,6 +233,9 @@ timer_notify (struct pt_regs *regs)
        int i;
        int is_user;
 
+       if ((++n_samples % INTERVAL) != 0)
+               return 0;
+       
        is_user = user_mode(regs);
 
        if (!current || current->pid == 0 || !current->mm)