From: Jan Beulich <jbeulich@suse.com>
Date: Mon, 15 Dec 2014 08:30:05 +0000 (+0100)
Subject: console: allocate ring buffer earlier
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=2676bc915157ab474ee478d929b0928cf696b385;p=people%2Fsstabellini%2Fxen-unstable.git%2F.git

console: allocate ring buffer earlier

... when "conring_size=" was specified on the command line. We can't
really do this as early as we would want to when the option was not
specified, as the default depends on knowing the system CPU count. Yet
the parsing of the ACPI tables is one of the things that generates a
lot of output especially on large systems.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com> (ARM and generic bits)
Release-Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
---

diff --git a/xen/arch/arm/setup.c b/xen/arch/arm/setup.c
index d2dcc3a71f..3991d64cc0 100644
--- a/xen/arch/arm/setup.c
+++ b/xen/arch/arm/setup.c
@@ -745,6 +745,7 @@ void __init start_xen(unsigned long boot_phys_offset,
 
     dt_uart_init();
     console_init_preirq();
+    console_init_ring();
 
     system_state = SYS_STATE_boot;
 
diff --git a/xen/arch/x86/setup.c b/xen/arch/x86/setup.c
index 73e95c69a7..c27c49c347 100644
--- a/xen/arch/x86/setup.c
+++ b/xen/arch/x86/setup.c
@@ -1187,6 +1187,7 @@ void __init noreturn __start_xen(unsigned long mbi_p)
     }
 
     vm_init();
+    console_init_ring();
     vesa_init();
 
     softirq_init();
diff --git a/xen/drivers/char/console.c b/xen/drivers/char/console.c
index 2f03259610..0b8d3d4a4d 100644
--- a/xen/drivers/char/console.c
+++ b/xen/drivers/char/console.c
@@ -744,15 +744,14 @@ void __init console_init_preirq(void)
     }
 }
 
-void __init console_init_postirq(void)
+void __init console_init_ring(void)
 {
     char *ring;
     unsigned int i, order, memflags;
-
-    serial_init_postirq();
+    unsigned long flags;
 
     if ( !opt_conring_size )
-        opt_conring_size = num_present_cpus() << (9 + xenlog_lower_thresh);
+        return;
 
     order = get_order_from_bytes(max(opt_conring_size, conring_size));
     memflags = MEMF_bits(crashinfo_maxaddr_bits);
@@ -763,17 +762,30 @@ void __init console_init_postirq(void)
     }
     opt_conring_size = PAGE_SIZE << order;
 
-    spin_lock_irq(&console_lock);
+    spin_lock_irqsave(&console_lock, flags);
     for ( i = conringc ; i != conringp; i++ )
         ring[i & (opt_conring_size - 1)] = conring[i & (conring_size - 1)];
     conring = ring;
     smp_wmb(); /* Allow users of console_force_unlock() to see larger buffer. */
     conring_size = opt_conring_size;
-    spin_unlock_irq(&console_lock);
+    spin_unlock_irqrestore(&console_lock, flags);
 
     printk("Allocated console ring of %u KiB.\n", opt_conring_size >> 10);
 }
 
+void __init console_init_postirq(void)
+{
+    serial_init_postirq();
+
+    if ( conring != _conring )
+        return;
+
+    if ( !opt_conring_size )
+        opt_conring_size = num_present_cpus() << (9 + xenlog_lower_thresh);
+
+    console_init_ring();
+}
+
 void __init console_endboot(void)
 {
     int i, j;
diff --git a/xen/include/xen/console.h b/xen/include/xen/console.h
index cfb07a23e0..c7fd9ca8ea 100644
--- a/xen/include/xen/console.h
+++ b/xen/include/xen/console.h
@@ -14,6 +14,7 @@ struct xen_sysctl_readconsole;
 long read_console_ring(struct xen_sysctl_readconsole *op);
 
 void console_init_preirq(void);
+void console_init_ring(void);
 void console_init_postirq(void);
 void console_endboot(void);
 int console_has(const char *device);