Re: [Patch0/4]: fake numa for x86_64 patches

[Andrew Morton <akpm@osdl.org>]

On Wed, 22 Nov 2006 17:34:04 -0800
Rohit Seth <rohitseth@google.com> wrote:

> This patch set resolves issues with running fake numa on x86_64.  We
> have also extended the command line numa=fake=NUM command line option to
> specify different size nodes.  The default NODES_SHIFT is also
> incremented from 6 to 8 to allow MAX_NUM_NODES to be 256.
> 
> Patch [1/4]: Add the e820_hole_size to give the size of hole in a given
> address range
> 
> Patch [2/4]: Increase the NODE_SHIFT from 6 to 8.
> 
> Patch [3/4]: Fix the existing numa=fake so that ioholes are
> appropriately configured.  Currently machines that have sizeable IO
> holes don't work with numa=fake>4.
> 
> Patch[4/4]: Extend the command line so that user can specify different
> size nodes on a command line.

These patches comprehensively conflict with the below.  It looks like the
fake-numa patches need more testing, so I'll drop Amul's patch.

Also, please don't send multiple patches under the same title.  I have four
patches, all the same.  Is lovingly covered in
http://www.zip.com.au/~akpm/linux/patches/stuff/tpp.txt, section 2.

Thanks.





From: Amul Shah <amul.shah@unisys.com>

Remove the statically allocated memory to NUMA node hash map in favor of a
dynamically allocated memory to node hash map (it is cache aligned).

This patch has the nice side effect in that it allows the hash map to grow
for systems with large amounts of memory (256GB - 1TB), but suffer from
having small PCI space tacked onto the boot node (which is somewhere
between 192MB to 512MB on the ES7000).

Signed-off-by: Amul Shah <amul.shah@unisys.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---

 arch/x86_64/kernel/e820.c   |    6 ++
 arch/x86_64/kernel/setup.c  |    4 +
 arch/x86_64/mm/numa.c       |   73 +++++++++++++++++++++++++++++-----
 include/asm-x86_64/e820.h   |    1 
 include/asm-x86_64/mmzone.h |   13 +++---
 5 files changed, 82 insertions(+), 15 deletions(-)

diff -puN arch/x86_64/kernel/e820.c~x86_64-make-the-numa-hash-function-nodemap-allocation arch/x86_64/kernel/e820.c
--- a/arch/x86_64/kernel/e820.c~x86_64-make-the-numa-hash-function-nodemap-allocation
+++ a/arch/x86_64/kernel/e820.c
@@ -83,6 +83,12 @@ static inline int bad_addr(unsigned long
 		return 1;
 	}
 
+	/* NUMA memory to node map */
+	if (last >= nodemap_addr && addr < nodemap_addr + nodemap_size) {
+		*addrp = nodemap_addr + nodemap_size;
+		return 1;
+	}
+
 	/* XXX ramdisk image here? */ 
 	return 0;
 } 
diff -puN arch/x86_64/kernel/setup.c~x86_64-make-the-numa-hash-function-nodemap-allocation arch/x86_64/kernel/setup.c
--- a/arch/x86_64/kernel/setup.c~x86_64-make-the-numa-hash-function-nodemap-allocation
+++ a/arch/x86_64/kernel/setup.c
@@ -445,6 +445,10 @@ void __init setup_arch(char **cmdline_p)
 	if (ebda_addr)
 		reserve_bootmem_generic(ebda_addr, ebda_size);
 
+	/* reserve nodemap region */
+	if (nodemap_addr)
+		reserve_bootmem_generic(nodemap_addr, nodemap_size);
+
 #ifdef CONFIG_SMP
 	/*
 	 * But first pinch a few for the stack/trampoline stuff
diff -puN arch/x86_64/mm/numa.c~x86_64-make-the-numa-hash-function-nodemap-allocation arch/x86_64/mm/numa.c
--- a/arch/x86_64/mm/numa.c~x86_64-make-the-numa-hash-function-nodemap-allocation
+++ a/arch/x86_64/mm/numa.c
@@ -36,6 +36,8 @@ unsigned char apicid_to_node[MAX_LOCAL_A
 cpumask_t node_to_cpumask[MAX_NUMNODES] __read_mostly;
 
 int numa_off __initdata;
+unsigned long __initdata nodemap_addr;
+unsigned long __initdata nodemap_size;
 
 
 /*
@@ -52,34 +54,87 @@ populate_memnodemap(const struct bootnod
 	int res = -1;
 	unsigned long addr, end;
 
-	if (shift >= 64)
-		return -1;
-	memset(memnodemap, 0xff, sizeof(memnodemap));
+	memset(memnodemap, 0xff, memnodemapsize);
 	for (i = 0; i < numnodes; i++) {
 		addr = nodes[i].start;
 		end = nodes[i].end;
 		if (addr >= end)
 			continue;
-		if ((end >> shift) >= NODEMAPSIZE)
+		if ((end >> shift) >= memnodemapsize)
 			return 0;
 		do {
 			if (memnodemap[addr >> shift] != 0xff)
 				return -1;
 			memnodemap[addr >> shift] = i;
-                       addr += (1UL << shift);
+			addr += (1UL << shift);
 		} while (addr < end);
 		res = 1;
 	} 
 	return res;
 }
 
-int __init compute_hash_shift(struct bootnode *nodes, int numnodes)
+static int __init allocate_cachealigned_memnodemap(void)
+{
+	unsigned long pad, pad_addr;
+
+	memnodemap = memnode.embedded_map;
+	if (memnodemapsize <= 48) {
+		printk(KERN_DEBUG "NUMA: Allocated memnodemap from %lx - %lx\n",
+		       nodemap_addr, nodemap_addr + nodemap_size);
+		return 0;
+	}
+
+	pad = L1_CACHE_BYTES - 1;
+	pad_addr = 0x8000;
+	nodemap_size = pad + memnodemapsize;
+	nodemap_addr = find_e820_area(pad_addr, end_pfn<<PAGE_SHIFT,
+				      nodemap_size);
+	if (nodemap_addr == -1UL) {
+		printk(KERN_ERR
+		       "NUMA: Unable to allocate Memory to Node hash map\n");
+		nodemap_addr = nodemap_size = 0;
+		return -1;
+	}
+	pad_addr = (nodemap_addr + pad) & ~pad;
+	memnodemap = phys_to_virt(pad_addr);
+
+	printk(KERN_DEBUG "NUMA: Allocated memnodemap from %lx - %lx\n",
+	       nodemap_addr, nodemap_addr + nodemap_size);
+	return 0;
+}
+
+/*
+ * The LSB of all start and end addresses in the node map is the value of the
+ * maximum possible shift.
+ */
+static int __init
+extract_lsb_from_nodes (const struct bootnode *nodes, int numnodes)
 {
-	int shift = 20;
+	int i;
+	unsigned long start, end;
+	unsigned long bitfield = 0, memtop = 0;
 
-	while (populate_memnodemap(nodes, numnodes, shift + 1) >= 0)
-		shift++;
+	for (i = 0; i < numnodes; i++) {
+		start = nodes[i].start;
+		end = nodes[i].end;
+		if (start >= end)
+			continue;
+		bitfield |= start | end;
+		if (end > memtop)
+			memtop = end;
+	}
+	i = find_first_bit(&bitfield, sizeof(unsigned long)*8);
+	memnodemapsize = (memtop >> i)+1;
+	return i;
+}
+
+int __init compute_hash_shift(struct bootnode *nodes, int numnodes)
+{
+	int shift;
 
+	shift = extract_lsb_from_nodes(nodes, numnodes);
+	if (allocate_cachealigned_memnodemap())
+		return -1;
 	printk(KERN_DEBUG "NUMA: Using %d for the hash shift.\n",
 		shift);
 
diff -puN include/asm-x86_64/e820.h~x86_64-make-the-numa-hash-function-nodemap-allocation include/asm-x86_64/e820.h
--- a/include/asm-x86_64/e820.h~x86_64-make-the-numa-hash-function-nodemap-allocation
+++ a/include/asm-x86_64/e820.h
@@ -56,6 +56,7 @@ extern void finish_e820_parsing(void);
 extern struct e820map e820;
 
 extern unsigned ebda_addr, ebda_size;
+extern unsigned long nodemap_addr, nodemap_size;
 #endif/*!__ASSEMBLY__*/
 
 #endif/*__E820_HEADER*/
diff -puN include/asm-x86_64/mmzone.h~x86_64-make-the-numa-hash-function-nodemap-allocation include/asm-x86_64/mmzone.h
--- a/include/asm-x86_64/mmzone.h~x86_64-make-the-numa-hash-function-nodemap-allocation
+++ a/include/asm-x86_64/mmzone.h
@@ -11,24 +11,25 @@
 
 #include <asm/smp.h>
 
-/* Should really switch to dynamic allocation at some point */
-#define NODEMAPSIZE 0x4fff
-
 /* Simple perfect hash to map physical addresses to node numbers */
 struct memnode {
 	int shift;
-	u8 map[NODEMAPSIZE];
-} ____cacheline_aligned;
+	unsigned int mapsize;
+	u8 *map;
+	u8 embedded_map[64-16];
+} ____cacheline_aligned; /* total size = 64 bytes */
 extern struct memnode memnode;
 #define memnode_shift memnode.shift
 #define memnodemap memnode.map
+#define memnodemapsize memnode.mapsize
 
 extern struct pglist_data *node_data[];
 
 static inline __attribute__((pure)) int phys_to_nid(unsigned long addr) 
 { 
 	unsigned nid; 
-	VIRTUAL_BUG_ON((addr >> memnode_shift) >= NODEMAPSIZE);
+	VIRTUAL_BUG_ON(!memnodemap);
+	VIRTUAL_BUG_ON((addr >> memnode_shift) >= memnodemapsize);
 	nid = memnodemap[addr >> memnode_shift]; 
 	VIRTUAL_BUG_ON(nid >= MAX_NUMNODES || !node_data[nid]); 
 	return nid; 
_

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/