linux-kernel - [patch -mm 2/7] x86_64: split remaining fake nodes equally

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Thu, 1 Mar 2007 09:13:00 -0800 (PST)
From:	David Rientjes <rientjes@...gle.com>
To:	Andrew Morton <akpm@...ux-foundation.org>
cc:	Andi Kleen <ak@...e.de>, linux-kernel@...r.kernel.org
Subject: [patch -mm 2/7] x86_64: split remaining fake nodes equally

Extends the numa=fake x86_64 command-line option to split the remaining
system memory into equal-sized nodes.

For example:
numa=fake=2*512,4*	gives two 512M nodes and the remaining system
			memory is split into four approximately equal
			chunks.

This is beneficial for systems where the exact size of RAM is unknown or
not necessarily relevant, but the granularity with which nodes shall be
allocated is known.

Cc: Andi Kleen <ak@...e.de>
Signed-off-by: David Rientjes <rientjes@...gle.com>
---
 Documentation/x86_64/boot-options.txt |    4 +++-
 arch/x86_64/mm/numa.c                 |   22 ++++++++++++++++++----
 2 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/Documentation/x86_64/boot-options.txt b/Documentation/x86_64/boot-options.txt
--- a/Documentation/x86_64/boot-options.txt
+++ b/Documentation/x86_64/boot-options.txt
@@ -155,7 +155,9 @@ NUMA
 		depending on the sizes and coefficients listed.  For example:
 			numa=fake=2*512,1024,4*256
 		gives two 512M nodes, a 1024M node, and four 256M nodes.  The
-		remaining system RAM is allocated to an additional node.
+		remaining system RAM is allocated to an additional node.  If
+		the last character of CMDLINE is a *, the remaining system RAM
+		is instead divided up equally among its coefficient.
 
   numa=hotadd=percent
 		Only allow hotadd memory to preallocate page structures upto
diff --git a/arch/x86_64/mm/numa.c b/arch/x86_64/mm/numa.c
--- a/arch/x86_64/mm/numa.c
+++ b/arch/x86_64/mm/numa.c
@@ -421,11 +421,25 @@ static int __init numa_emulation(unsigned long start_pfn, unsigned long end_pfn)
 done:
 	if (!num_nodes)
 		return -1;
-	/* Fill remainder of system RAM with a final node, if appropriate. */
+	/* Fill remainder of system RAM, if appropriate. */
 	if (addr < max_addr) {
-		setup_node_range(num_nodes, nodes, &addr, max_addr - addr,
-				 max_addr);
-		num_nodes++;
+		switch (*(cmdline - 1)) {
+		case '*':
+			/* Split remaining nodes into coeff chunks */
+			if (coeff <= 0)
+				break;
+			num_nodes += split_nodes_equally(nodes, &addr, max_addr,
+							 num_nodes, coeff);
+			break;
+		case ',':
+			/* Do not allocate remaining system RAM */
+			break;
+		default:
+			/* Give one final node */
+			setup_node_range(num_nodes, nodes, &addr,
+					 max_addr - addr, max_addr);
+			num_nodes++;
+		}
 	}
 out:
 	memnode_shift = compute_hash_shift(nodes, num_nodes);
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/