From: Keir Fraser <keir.fraser@citrix.com>
Date: Fri, 11 Apr 2008 14:55:42 +0000 (+0100)
Subject: Turn some simple softirqs into tasklets.
X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~14231^2~18
X-Git-Url: https://dgit.raspbian.org/%22http:/www.example.com/cgi/%22https:/%22bookmarks://%22Dat/%22http:/www.example.com/cgi/%22https:/%22bookmarks:/%22Dat?a=commitdiff_plain;h=e9b5fb4377d1de367b6a14fca1493b4e6944d8c9;p=xen.git

Turn some simple softirqs into tasklets.

TRACE_SOFTIRQ does not appear to be necessary at all.

Signed-off-by: Keir Fraser <keir.fraser@citrix.com>
---

diff --git a/xen/arch/x86/traps.c b/xen/arch/x86/traps.c
index d9e1b57b22..c9f879b351 100644
--- a/xen/arch/x86/traps.c
+++ b/xen/arch/x86/traps.c
@@ -2637,12 +2637,14 @@ asmlinkage void do_general_protection(struct cpu_user_regs *regs)
     panic("GENERAL PROTECTION FAULT\n[error_code=%04x]\n", regs->error_code);
 }
 
-static void nmi_softirq(void)
+static void nmi_action(unsigned long unused)
 {
     /* Only used to defer wakeup of dom0,vcpu0 to a safe (non-NMI) context. */
     vcpu_kick(dom0->vcpu[0]);
 }
 
+static DECLARE_TASKLET(nmi_tasklet, nmi_action, 0);
+
 static void nmi_dom0_report(unsigned int reason_idx)
 {
     struct domain *d;
@@ -2654,7 +2656,7 @@ static void nmi_dom0_report(unsigned int reason_idx)
     set_bit(reason_idx, nmi_reason(d));
 
     if ( !test_and_set_bool(v->nmi_pending) )
-        raise_softirq(NMI_SOFTIRQ); /* not safe to wake up a vcpu here */
+        tasklet_schedule(&nmi_tasklet); /* not safe to wake a vcpu here */
 }
 
 asmlinkage void mem_parity_error(struct cpu_user_regs *regs)
@@ -2932,8 +2934,6 @@ void __init trap_init(void)
     percpu_traps_init();
 
     cpu_init();
-
-    open_softirq(NMI_SOFTIRQ, nmi_softirq);
 }
 
 long register_guest_nmi_callback(unsigned long address)
diff --git a/xen/common/keyhandler.c b/xen/common/keyhandler.c
index b414452562..934edb5dc9 100644
--- a/xen/common/keyhandler.c
+++ b/xen/common/keyhandler.c
@@ -32,7 +32,7 @@ static struct {
 
 static unsigned char keypress_key;
 
-static void keypress_softirq(void)
+static void keypress_action(unsigned long unused)
 {
     keyhandler_t *h;
     unsigned char key = keypress_key;
@@ -42,6 +42,8 @@ static void keypress_softirq(void)
     console_end_log_everything();
 }
 
+static DECLARE_TASKLET(keypress_tasklet, keypress_action, 0);
+
 void handle_keypress(unsigned char key, struct cpu_user_regs *regs)
 {
     irq_keyhandler_t *h;
@@ -56,7 +58,7 @@ void handle_keypress(unsigned char key, struct cpu_user_regs *regs)
     else
     {
         keypress_key = key;
-        raise_softirq(KEYPRESS_SOFTIRQ);
+        tasklet_schedule(&keypress_tasklet);
     }
 }
 
@@ -284,8 +286,6 @@ static void do_debug_key(unsigned char key, struct cpu_user_regs *regs)
 
 void __init initialize_keytable(void)
 {
-    open_softirq(KEYPRESS_SOFTIRQ, keypress_softirq);
-
     register_irq_keyhandler(
         'd', dump_registers, "dump registers");
     register_keyhandler(
diff --git a/xen/common/trace.c b/xen/common/trace.c
index 863816b9ee..12ff7a029c 100644
--- a/xen/common/trace.c
+++ b/xen/common/trace.c
@@ -69,12 +69,6 @@ static cpumask_t tb_cpu_mask = CPU_MASK_ALL;
 /* which tracing events are enabled */
 static u32 tb_event_mask = TRC_ALL;
 
-static void trace_notify_guest(void)
-{
-    send_guest_global_virq(dom0, VIRQ_TBUF);
-}
-
-
 /**
  * alloc_trace_bufs - performs initialization of the per-cpu trace buffers.
  *
@@ -120,7 +114,6 @@ static int alloc_trace_bufs(void)
     }
 
     t_buf_highwater = data_size >> 1; /* 50% high water */
-    open_softirq(TRACE_SOFTIRQ, trace_notify_guest);
 
     return 0;
 }
@@ -513,7 +506,7 @@ void __trace_var(u32 event, int cycles, int extra, unsigned char *extra_data)
     /* Notify trace buffer consumer that we've crossed the high water mark. */
     if ( started_below_highwater &&
          (calc_unconsumed_bytes(buf) >= t_buf_highwater) )
-        raise_softirq(TRACE_SOFTIRQ);
+        send_guest_global_virq(dom0, VIRQ_TBUF);
 }
 
 /*
diff --git a/xen/include/xen/softirq.h b/xen/include/xen/softirq.h
index 440bfa6c6c..dbf4606261 100644
--- a/xen/include/xen/softirq.h
+++ b/xen/include/xen/softirq.h
@@ -6,10 +6,7 @@ enum {
     TIMER_SOFTIRQ = 0,
     SCHEDULE_SOFTIRQ,
     NEW_TLBFLUSH_CLOCK_PERIOD_SOFTIRQ,
-    KEYPRESS_SOFTIRQ,
-    NMI_SOFTIRQ,
     PAGE_SCRUB_SOFTIRQ,
-    TRACE_SOFTIRQ,
     RCU_SOFTIRQ,
     STOPMACHINE_SOFTIRQ,
     TASKLET_SOFTIRQ,