[PATCH] add coherence id for SGI Altix systems

[PATCH] add coherence id for SGI Altix systems

[Dean Roe]

Current SGI Altix systems have a NUMAlink domain size of 1024
compute nodes and are fully cache coherent up to 256 compute
nodes (compute nodes are even-numbered).  Systems larger than
256 nodes are partitioned into multiple cache coherent systems.
This patch exports a partition's coherence id to users via the
/proc/sgi_sn/coherence_id file.

Signed-off-by: Dean Roe <roe@sgi.com>



Index: bk-work/include/asm-ia64/sn/sn_cpuid.h
=================================--- bk-work.orig/include/asm-ia64/sn/sn_cpuid.h	2004-08-10 14:23:26.000000000 -0500
+++ bk-work/include/asm-ia64/sn/sn_cpuid.h	2004-08-13 11:04:34.000000000 -0500
@@ -4,7 +4,7 @@
  * License.  See the file "COPYING" in the main directory of this archive
  * for more details.
  *
- * Copyright (C) 2000-2003 Silicon Graphics, Inc. All rights reserved.
+ * Copyright (C) 2000-2004 Silicon Graphics, Inc. All rights reserved.
  */
 
 
@@ -93,6 +93,7 @@
  */
 #define cpu_physical_id_to_nasid(cpi)		((cpi) &0xfff)
 #define cpu_physical_id_to_slice(cpi)		((cpi>>12) & 3)
+#define cpu_physical_id_to_coherence_id(cpi)	(cpu_physical_id_to_nasid(cpi) >> 9)
 #define get_nasid()				((ia64_getreg(_IA64_REG_CR_LID) >> 16) & 0xfff)
 #define get_slice()				((ia64_getreg(_IA64_REG_CR_LID) >> 28) & 0xf)
 #define get_node_number(addr)			(((unsigned long)(addr)>>38) & 0x7ff)
@@ -172,6 +173,11 @@
 
 #define smp_physical_node_id()			(cpuid_to_nasid(smp_processor_id()))
 
+/*
+ * cpuid_to_coherence_id - convert a cpuid to the coherence domain id it
+ * resides on
+ */
+#define cpuid_to_coherence_id(cpuid)	cpu_physical_id_to_coherence_id(cpu_physical_id(cpuid))
 
 #endif /* _ASM_IA64_SN_SN_CPUID_H */
 
Index: bk-work/arch/ia64/sn/kernel/sn2/sn_proc_fs.c
=================================--- bk-work.orig/arch/ia64/sn/kernel/sn2/sn_proc_fs.c	2004-08-10 14:23:59.000000000 -0500
+++ bk-work/arch/ia64/sn/kernel/sn2/sn_proc_fs.c	2004-08-13 11:05:06.000000000 -0500
@@ -3,7 +3,7 @@
  * License.  See the file "COPYING" in the main directory of this archive
  * for more details.
  *
- * Copyright (C) 2000-2003 Silicon Graphics, Inc. All rights reserved.
+ * Copyright (C) 2000-2004 Silicon Graphics, Inc. All rights reserved.
  */
 #include <linux/config.h>
 #include <asm/uaccess.h>
@@ -118,11 +118,33 @@
 	}
 }
 
+static int coherence_id_read_proc(char *page, char **start, off_t off,
+		int count, int *eof, void *data) {
+	return sprintf(page, "%d\n", cpuid_to_coherence_id(smp_processor_id()));
+}
+
+void
+register_sn_coherence_id(void) {
+	struct proc_dir_entry *entry;
+
+	if (!sgi_proc_dir) {
+		sgi_proc_dir = proc_mkdir("sgi_sn", 0);
+	}
+	entry = create_proc_entry("coherence_id", 0444, sgi_proc_dir);
+	if (entry) {
+		entry->nlink = 1;
+		entry->data = 0;
+		entry->read_proc = coherence_id_read_proc;
+		entry->write_proc = NULL;
+	}
+}
+
 void
 register_sn_procfs(void) {
 	register_sn_partition_id();
 	register_sn_serial_numbers();
 	register_sn_force_interrupt();
+	register_sn_coherence_id();
 }
 
 #endif /* CONFIG_PROC_FS */

Re: [PATCH] add coherence id for SGI Altix systems

[Christoph Hellwig]

On Fri, Aug 13, 2004 at 12:56:32PM -0500, Dean Roe wrote:
> +static int coherence_id_read_proc(char *page, char **start, off_t off,
> +		int count, int *eof, void *data) {

The { needs to go on a new line

> +	return sprintf(page, "%d\n", cpuid_to_coherence_id(smp_processor_id()));
> +}

please use the seq_file api.

> +void
> +register_sn_coherence_id(void) {

{ pleasement again, and this should be static.

> +	struct proc_dir_entry *entry;
> +
> +	if (!sgi_proc_dir) {
> +		sgi_proc_dir = proc_mkdir("sgi_sn", 0);
> +	}

don't SN2 systems have this directory already?

> +		entry->nlink = 1;
> +		entry->data = 0;

no need to set this two.

> +		entry->write_proc = NULL;

dito.


also while you're at it convert the whole file to seq_file and proper
coding style.

Re: [PATCH] add coherence id for SGI Altix systems

[Russ Anderson]

Christoph Hellwig wrote:
> 
> also while you're at it convert the whole file to seq_file and proper
> coding style.

Shouldn't coding style changes be a separate patch?  Otherwise
it's hard to tell the real changes from the code style changes.

-- 
Russ Anderson, OS RAS/Partitioning Project Lead  
SGI - Silicon Graphics Inc          rja@sgi.com

Re: [PATCH] add coherence id for SGI Altix systems

[Christoph Hellwig]

On Fri, Aug 13, 2004 at 01:41:13PM -0500, Russ Anderson wrote:
> Christoph Hellwig wrote:
> > 
> > also while you're at it convert the whole file to seq_file and proper
> > coding style.
> 
> Shouldn't coding style changes be a separate patch?  Otherwise
> it's hard to tell the real changes from the code style changes.

"while you're at it" wasn't meant as in the same patch, but as a reminder
that additional patches to clean up that area would be very welcome ;-)