Re: [PATCH] Fake NUMA emulation for PowerPC (Take 2)
Balbir Singh writes: Here's a better and more complete fix for the problem. Could you please see if it works for you? I tested it on a real NUMA box and it seemed to work fine there. There are a couple of other changes in behaviour that your patch introduces, and I'd like to understand them better before taking the patch. First, with your patch we don't set nodes online if they end up having no memory in them because of the memory limit, whereas previously we did. Secondly, in the case where we don't have NUMA information, we now set node 0 online after adding each LMB, whereas previously we only set it online once. If in fact these changes are benign, then your patch description should mention them and explain why they are benign. Paul. ___ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
Re: [PATCH] Fake NUMA emulation for PowerPC (Take 2)
* Paul Mackerras [EMAIL PROTECTED] [2008-01-27 22:55:43]: Balbir Singh writes: Here's a better and more complete fix for the problem. Could you please see if it works for you? I tested it on a real NUMA box and it seemed to work fine there. There are a couple of other changes in behaviour that your patch introduces, and I'd like to understand them better before taking the patch. First, with your patch we don't set nodes online if they end up having no memory in them because of the memory limit, whereas previously we did. Secondly, in the case where we don't have NUMA information, we now set node 0 online after adding each LMB, whereas previously we only set it online once. If in fact these changes are benign, then your patch description should mention them and explain why they are benign. Yes, they are. I'll try and justify the changes with a good detailed changelog. If people prefer it, I can hide fake NUMA nodes under a config option, so that it does not come enabled by default. Thanks for keeping me honest. Paul. ___ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev -- Warm Regards, Balbir Singh Linux Technology Center IBM, ISTL ___ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
Re: [PATCH] Fake NUMA emulation for PowerPC (Take 2)
On 1/27/08, Balbir Singh [EMAIL PROTECTED] wrote: * Paul Mackerras [EMAIL PROTECTED] [2008-01-27 22:55:43]: Balbir Singh writes: Here's a better and more complete fix for the problem. Could you please see if it works for you? I tested it on a real NUMA box and it seemed to work fine there. There are a couple of other changes in behaviour that your patch introduces, and I'd like to understand them better before taking the patch. First, with your patch we don't set nodes online if they end up having no memory in them because of the memory limit, whereas previously we did. Secondly, in the case where we don't have NUMA information, we now set node 0 online after adding each LMB, whereas previously we only set it online once. If in fact these changes are benign, then your patch description should mention them and explain why they are benign. Yes, they are. I'll try and justify the changes with a good detailed changelog. If people prefer it, I can hide fake NUMA nodes under a config option, so that it does not come enabled by default. Sigh, there already *is* a fake NUMA config option: CONFIG_NUMA_EMU. CONFIG_NUMA_EMU: Enable NUMA emulation. A flat machine will be split into virtual nodes when booted with numa=fake=N, where N is the number of nodes. This is only useful for debugging. I have to assume your patch is implementing the same feature for powerpc (really just extending the x86_64 one), and thus should share the config option. Any chance you can just make some of that code common? Maybe as a follow-on patch. I expect that some of Mel's (added to Cc) work to allow NUMA to be set on x86 more easily will flow quite simply into adding fake NUMA support there as well. So moving the code to a common place (at least the parsing) makes sense. I also feel like you want to be able to online memoryless nodes -- that's where we've been hitting a number of bugs lately in the VM. I can't tell from Paul's comment if your patch prevents that from being faked or not. Thanks, Nish ___ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
Re: [PATCH] Fake NUMA emulation for PowerPC (Take 2)
* Michael Ellerman [EMAIL PROTECTED] [2008-01-18 16:44:58]:
This fixes it, although I'm a little worried about some of the
removals/movings of node_set_online() in the patch.
diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c
index 1666e7d..dcedc26 100644
--- a/arch/powerpc/mm/numa.c
+++ b/arch/powerpc/mm/numa.c
@@ -49,7 +49,6 @@ static int __cpuinit fake_numa_create_new_node(unsigned
long end_pfn,
static unsigned int fake_nid = 0;
static unsigned long long curr_boundary = 0;
- *nid = fake_nid;
if (!p)
return 0;
@@ -60,6 +59,7 @@ static int __cpuinit fake_numa_create_new_node(unsigned
long end_pfn,
if (mem curr_boundary)
return 0;
+ *nid = fake_nid;
curr_boundary = mem;
if ((end_pfn PAGE_SHIFT) mem) {
Hi, Michael,
Here's a better and more complete fix for the problem. Could you
please see if it works for you? I tested it on a real NUMA box and it
seemed to work fine there.
Description
---
This patch provides a fix for the problem found by
Michael Ellerman [EMAIL PROTECTED] while using fake NUMA nodes
on a cell box. The code modifies node id iff (as in if and only if)
fake NUMA nodes are created.
Signed-off-by: Balbir Singh [EMAIL PROTECTED]
---
arch/powerpc/mm/numa.c |7 ++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff -puN arch/powerpc/mm/numa.c~fix-fake-numa-nid-on-numa
arch/powerpc/mm/numa.c
--- linux-2.6.24-rc8/arch/powerpc/mm/numa.c~fix-fake-numa-nid-on-numa
2008-01-26 12:20:29.0 +0530
+++ linux-2.6.24-rc8-balbir/arch/powerpc/mm/numa.c 2008-01-26
12:27:53.0 +0530
@@ -49,7 +49,12 @@ static int __cpuinit fake_numa_create_ne
static unsigned int fake_nid = 0;
static unsigned long long curr_boundary = 0;
- *nid = fake_nid;
+ /*
+* If we did enable fake nodes and cross a node,
+* remember the last node and start from there.
+*/
+ if (fake_nid)
+ *nid = fake_nid;
if (!p)
return 0;
_
--
Warm Regards,
Balbir Singh
Linux Technology Center
IBM, ISTL
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Re: [PATCH] Fake NUMA emulation for PowerPC (Take 2)
* Michael Ellerman [EMAIL PROTECTED] [2008-01-18 16:44:58]:
On Fri, 2008-01-18 at 16:34 +1100, Michael Ellerman wrote:
On Sat, 2007-12-08 at 04:07 +0530, Balbir Singh wrote:
Changelog
1. Get rid of the constant 5 (based on comments from
[EMAIL PROTECTED])
2. Implement suggestions from Olof Johannson
3. Check if cmdline is NULL in fake_numa_create_new_node()
Tested with additional parameters from Olof
numa=debug,fake=
numa=foo,fake=bar
I'm not sure why yet, but git bisect tells me it's this patch that's
causing the for-2.6.25 tree to explode on boot on cell machines.
This fixes it, although I'm a little worried about some of the
removals/movings of node_set_online() in the patch.
diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c
index 1666e7d..dcedc26 100644
--- a/arch/powerpc/mm/numa.c
+++ b/arch/powerpc/mm/numa.c
@@ -49,7 +49,6 @@ static int __cpuinit fake_numa_create_new_node(unsigned
long end_pfn,
static unsigned int fake_nid = 0;
static unsigned long long curr_boundary = 0;
- *nid = fake_nid;
if (!p)
return 0;
@@ -60,6 +59,7 @@ static int __cpuinit fake_numa_create_new_node(unsigned
long end_pfn,
if (mem curr_boundary)
return 0;
+ *nid = fake_nid;
curr_boundary = mem;
if ((end_pfn PAGE_SHIFT) mem) {
This patch makes sense, ideally fake_numa_create_new_node() should
just be a no-op in the case of machines with real NUMA nodes.
--
Warm Regards,
Balbir Singh
Linux Technology Center
IBM, ISTL
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Re: [PATCH] Fake NUMA emulation for PowerPC (Take 2)
* Michael Ellerman [EMAIL PROTECTED] [2008-01-18 16:55:03]:
On Sat, 2007-12-08 at 04:07 +0530, Balbir Singh wrote:
Here's a dumb simple implementation of fake NUMA nodes for PowerPC. Fake
NUMA nodes can be specified using the following command line option
Comments are as always welcome!
Here's some :)
Thanks!
diff -puN arch/powerpc/mm/numa.c~ppc-fake-numa-easy arch/powerpc/mm/numa.c
--- linux-2.6.24-rc4-mm1/arch/powerpc/mm/numa.c~ppc-fake-numa-easy
2007-12-07 21:25:55.0 +0530
+++ linux-2.6.24-rc4-mm1-balbir/arch/powerpc/mm/numa.c 2007-12-08
03:19:46.0 +0530
@@ -24,6 +24,8 @@
static int numa_enabled = 1;
+static char *cmdline __initdata;
Can you call this fake_numa_args or something, cmdline is a bit generic.
I could if it makes code easier to understand. Will put it in my TODO
list.
@@ -39,6 +41,43 @@ static bootmem_data_t __initdata plat_no
static int min_common_depth;
static int n_mem_addr_cells, n_mem_size_cells;
+static int __cpuinit fake_numa_create_new_node(unsigned long end_pfn,
+ unsigned int *nid)
+{
+ unsigned long long mem;
+ char *p = cmdline;
+ static unsigned int fake_nid = 0;
+ static unsigned long long curr_boundary = 0;
+
+ *nid = fake_nid;
As I mentioned in my other email I think this is broken, you
unconditionally overwrite *nid, even if no fake numa was specified?
Aah.. OK.. looks like a BUG. I'll also respond to your other email.
+ if (!p)
+ return 0;
+
+ mem = memparse(p, p);
+ if (!mem)
+ return 0;
+
+ if (mem curr_boundary)
+ return 0;
+
+ curr_boundary = mem;
+
+ if ((end_pfn PAGE_SHIFT) mem) {
+ /*
+* Skip commas and spaces
+*/
+ while (*p == ',' || *p == ' ' || *p == '\t')
+ p++;
+
+ cmdline = p;
+ fake_nid++;
+ *nid = fake_nid;
+ dbg(created new fake_node with id %d\n, fake_nid);
+ return 1;
+ }
+ return 0;
+}
+
static void __cpuinit map_cpu_to_node(int cpu, int node)
{
numa_cpu_lookup_table[cpu] = node;
@@ -344,12 +383,14 @@ static void __init parse_drconf_memory(s
if (nid == 0x || nid = MAX_NUMNODES)
nid = default_nid;
}
- node_set_online(nid);
size = numa_enforce_memory_limit(start, lmb_size);
if (!size)
continue;
+ fake_numa_create_new_node(((start + size) PAGE_SHIFT), nid);
+ node_set_online(nid);
I can't convince myself that this is 100% ok, the moving of
node_set_online(). At the very least it's a change in behaviour,
previously we would online the node regardless of the memory limit.
Hmm.. this can be reverted, but do we gain anything by enabling nodes,
even though we are over the memory limit?
add_active_range(nid, start PAGE_SHIFT,
(start PAGE_SHIFT) + (size PAGE_SHIFT));
}
@@ -429,7 +470,6 @@ new_range:
nid = of_node_to_nid_single(memory);
if (nid 0)
nid = default_nid;
- node_set_online(nid);
if (!(size = numa_enforce_memory_limit(start, size))) {
if (--ranges)
@@ -438,6 +478,9 @@ new_range:
continue;
}
+ fake_numa_create_new_node(((start + size) PAGE_SHIFT), nid);
+ node_set_online(nid);
Ditto previous comment.
Yes, point noted.
Thanks for your review and problem report.
cheers
--
Michael Ellerman
OzLabs, IBM Australia Development Lab
wwweb: http://michael.ellerman.id.au
phone: +61 2 6212 1183 (tie line 70 21183)
We do not inherit the earth from our ancestors,
we borrow it from our children. - S.M.A.R.T Person
--
Warm Regards,
Balbir Singh
Linux Technology Center
IBM, ISTL
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Re: [PATCH] Fake NUMA emulation for PowerPC (Take 2)
* Michael Ellerman [EMAIL PROTECTED] [2008-01-18 16:34:53]: On Sat, 2007-12-08 at 04:07 +0530, Balbir Singh wrote: Changelog 1. Get rid of the constant 5 (based on comments from [EMAIL PROTECTED]) 2. Implement suggestions from Olof Johannson 3. Check if cmdline is NULL in fake_numa_create_new_node() Tested with additional parameters from Olof numa=debug,fake= numa=foo,fake=bar I'm not sure why yet, but git bisect tells me it's this patch that's causing the for-2.6.25 tree to explode on boot on cell machines. Hi, Do you boot with numa=options on your machine? Could I have your machine configuration? Any OOPS/log would be helpful. -- Warm Regards, Balbir Singh Linux Technology Center IBM, ISTL ___ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
Re: [PATCH] Fake NUMA emulation for PowerPC (Take 2)
On Sat, 2007-12-08 at 04:07 +0530, Balbir Singh wrote: Changelog 1. Get rid of the constant 5 (based on comments from [EMAIL PROTECTED]) 2. Implement suggestions from Olof Johannson 3. Check if cmdline is NULL in fake_numa_create_new_node() Tested with additional parameters from Olof numa=debug,fake= numa=foo,fake=bar I'm not sure why yet, but git bisect tells me it's this patch that's causing the for-2.6.25 tree to explode on boot on cell machines. cheers -- Michael Ellerman OzLabs, IBM Australia Development Lab wwweb: http://michael.ellerman.id.au phone: +61 2 6212 1183 (tie line 70 21183) We do not inherit the earth from our ancestors, we borrow it from our children. - S.M.A.R.T Person signature.asc Description: This is a digitally signed message part ___ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
Re: [PATCH] Fake NUMA emulation for PowerPC (Take 2)
On Fri, 2008-01-18 at 16:34 +1100, Michael Ellerman wrote:
On Sat, 2007-12-08 at 04:07 +0530, Balbir Singh wrote:
Changelog
1. Get rid of the constant 5 (based on comments from
[EMAIL PROTECTED])
2. Implement suggestions from Olof Johannson
3. Check if cmdline is NULL in fake_numa_create_new_node()
Tested with additional parameters from Olof
numa=debug,fake=
numa=foo,fake=bar
I'm not sure why yet, but git bisect tells me it's this patch that's
causing the for-2.6.25 tree to explode on boot on cell machines.
This fixes it, although I'm a little worried about some of the
removals/movings of node_set_online() in the patch.
diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c
index 1666e7d..dcedc26 100644
--- a/arch/powerpc/mm/numa.c
+++ b/arch/powerpc/mm/numa.c
@@ -49,7 +49,6 @@ static int __cpuinit fake_numa_create_new_node(unsigned long
end_pfn,
static unsigned int fake_nid = 0;
static unsigned long long curr_boundary = 0;
- *nid = fake_nid;
if (!p)
return 0;
@@ -60,6 +59,7 @@ static int __cpuinit fake_numa_create_new_node(unsigned long
end_pfn,
if (mem curr_boundary)
return 0;
+ *nid = fake_nid;
curr_boundary = mem;
if ((end_pfn PAGE_SHIFT) mem) {
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Re: [PATCH] Fake NUMA emulation for PowerPC (Take 2)
On Sat, 2007-12-08 at 04:07 +0530, Balbir Singh wrote:
Here's a dumb simple implementation of fake NUMA nodes for PowerPC. Fake
NUMA nodes can be specified using the following command line option
Comments are as always welcome!
Here's some :)
diff -puN arch/powerpc/mm/numa.c~ppc-fake-numa-easy arch/powerpc/mm/numa.c
--- linux-2.6.24-rc4-mm1/arch/powerpc/mm/numa.c~ppc-fake-numa-easy
2007-12-07 21:25:55.0 +0530
+++ linux-2.6.24-rc4-mm1-balbir/arch/powerpc/mm/numa.c2007-12-08
03:19:46.0 +0530
@@ -24,6 +24,8 @@
static int numa_enabled = 1;
+static char *cmdline __initdata;
Can you call this fake_numa_args or something, cmdline is a bit generic.
@@ -39,6 +41,43 @@ static bootmem_data_t __initdata plat_no
static int min_common_depth;
static int n_mem_addr_cells, n_mem_size_cells;
+static int __cpuinit fake_numa_create_new_node(unsigned long end_pfn,
+ unsigned int *nid)
+{
+ unsigned long long mem;
+ char *p = cmdline;
+ static unsigned int fake_nid = 0;
+ static unsigned long long curr_boundary = 0;
+
+ *nid = fake_nid;
As I mentioned in my other email I think this is broken, you
unconditionally overwrite *nid, even if no fake numa was specified?
+ if (!p)
+ return 0;
+
+ mem = memparse(p, p);
+ if (!mem)
+ return 0;
+
+ if (mem curr_boundary)
+ return 0;
+
+ curr_boundary = mem;
+
+ if ((end_pfn PAGE_SHIFT) mem) {
+ /*
+ * Skip commas and spaces
+ */
+ while (*p == ',' || *p == ' ' || *p == '\t')
+ p++;
+
+ cmdline = p;
+ fake_nid++;
+ *nid = fake_nid;
+ dbg(created new fake_node with id %d\n, fake_nid);
+ return 1;
+ }
+ return 0;
+}
+
static void __cpuinit map_cpu_to_node(int cpu, int node)
{
numa_cpu_lookup_table[cpu] = node;
@@ -344,12 +383,14 @@ static void __init parse_drconf_memory(s
if (nid == 0x || nid = MAX_NUMNODES)
nid = default_nid;
}
- node_set_online(nid);
size = numa_enforce_memory_limit(start, lmb_size);
if (!size)
continue;
+ fake_numa_create_new_node(((start + size) PAGE_SHIFT), nid);
+ node_set_online(nid);
I can't convince myself that this is 100% ok, the moving of
node_set_online(). At the very least it's a change in behaviour,
previously we would online the node regardless of the memory limit.
add_active_range(nid, start PAGE_SHIFT,
(start PAGE_SHIFT) + (size PAGE_SHIFT));
}
@@ -429,7 +470,6 @@ new_range:
nid = of_node_to_nid_single(memory);
if (nid 0)
nid = default_nid;
- node_set_online(nid);
if (!(size = numa_enforce_memory_limit(start, size))) {
if (--ranges)
@@ -438,6 +478,9 @@ new_range:
continue;
}
+ fake_numa_create_new_node(((start + size) PAGE_SHIFT), nid);
+ node_set_online(nid);
Ditto previous comment.
cheers
--
Michael Ellerman
OzLabs, IBM Australia Development Lab
wwweb: http://michael.ellerman.id.au
phone: +61 2 6212 1183 (tie line 70 21183)
We do not inherit the earth from our ancestors,
we borrow it from our children. - S.M.A.R.T Person
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Re: [PATCH] Fake NUMA emulation for PowerPC (Take 2)
Balbir Singh wrote:
Changelog
1. Get rid of the constant 5 (based on comments from
[EMAIL PROTECTED])
2. Implement suggestions from Olof Johannson
3. Check if cmdline is NULL in fake_numa_create_new_node()
Tested with additional parameters from Olof
numa=debug,fake=
numa=foo,fake=bar
Here's a dumb simple implementation of fake NUMA nodes for PowerPC. Fake
NUMA nodes can be specified using the following command line option
numa=fake=node range
node range is of the format range1,range2,...rangeN
Each of the rangeX parameters is passed using memparse(). I find the patch
useful for fake NUMA emulation on my simple PowerPC machine. I've tested it
on a non-numa box with the following arguments
numa=fake=1G
numa=fake=1G,2G
name=fake=1G,512M,2G
numa=fake=1500M,2800M mem=3500M
numa=fake=1G mem=512M
numa=fake=1G mem=1G
This patch applies on top of 2.6.24-rc4.
All though I've tried my best to handle some of the architecture specific
details of PowerPC, I might have overlooked something obvious, like the usage
of an API or some architecture tweaks. The patch depends on CONFIG_NUMA and
I decided against creating a separate config option for fake NUMA to keep
the code simple.
Comments are as always welcome!
Signed-off-by: Balbir Singh [EMAIL PROTECTED]
---
arch/powerpc/mm/numa.c | 59
-
1 file changed, 54 insertions(+), 5 deletions(-)
diff -puN arch/powerpc/mm/numa.c~ppc-fake-numa-easy arch/powerpc/mm/numa.c
--- linux-2.6.24-rc4-mm1/arch/powerpc/mm/numa.c~ppc-fake-numa-easy
2007-12-07 21:25:55.0 +0530
+++ linux-2.6.24-rc4-mm1-balbir/arch/powerpc/mm/numa.c2007-12-08
03:19:46.0 +0530
@@ -24,6 +24,8 @@
static int numa_enabled = 1;
+static char *cmdline __initdata;
+
static int numa_debug;
#define dbg(args...) if (numa_debug) { printk(KERN_INFO args); }
@@ -39,6 +41,43 @@ static bootmem_data_t __initdata plat_no
static int min_common_depth;
static int n_mem_addr_cells, n_mem_size_cells;
+static int __cpuinit fake_numa_create_new_node(unsigned long end_pfn,
+ unsigned int *nid)
+{
+ unsigned long long mem;
+ char *p = cmdline;
+ static unsigned int fake_nid = 0;
+ static unsigned long long curr_boundary = 0;
+
+ *nid = fake_nid;
+ if (!p)
+ return 0;
+
+ mem = memparse(p, p);
+ if (!mem)
+ return 0;
+
+ if (mem curr_boundary)
+ return 0;
+
+ curr_boundary = mem;
+
+ if ((end_pfn PAGE_SHIFT) mem) {
+ /*
+ * Skip commas and spaces
+ */
+ while (*p == ',' || *p == ' ' || *p == '\t')
+ p++;
+
+ cmdline = p;
+ fake_nid++;
+ *nid = fake_nid;
+ dbg(created new fake_node with id %d\n, fake_nid);
+ return 1;
+ }
+ return 0;
+}
+
static void __cpuinit map_cpu_to_node(int cpu, int node)
{
numa_cpu_lookup_table[cpu] = node;
@@ -344,12 +383,14 @@ static void __init parse_drconf_memory(s
if (nid == 0x || nid = MAX_NUMNODES)
nid = default_nid;
}
- node_set_online(nid);
size = numa_enforce_memory_limit(start, lmb_size);
if (!size)
continue;
+ fake_numa_create_new_node(((start + size) PAGE_SHIFT), nid);
+ node_set_online(nid);
+
add_active_range(nid, start PAGE_SHIFT,
(start PAGE_SHIFT) + (size PAGE_SHIFT));
}
@@ -429,7 +470,6 @@ new_range:
nid = of_node_to_nid_single(memory);
if (nid 0)
nid = default_nid;
- node_set_online(nid);
if (!(size = numa_enforce_memory_limit(start, size))) {
if (--ranges)
@@ -438,6 +478,9 @@ new_range:
continue;
}
+ fake_numa_create_new_node(((start + size) PAGE_SHIFT), nid);
+ node_set_online(nid);
+
add_active_range(nid, start PAGE_SHIFT,
(start PAGE_SHIFT) + (size PAGE_SHIFT));
@@ -461,7 +504,7 @@ static void __init setup_nonnuma(void)
unsigned long top_of_ram = lmb_end_of_DRAM();
unsigned long total_ram = lmb_phys_mem_size();
unsigned long start_pfn, end_pfn;
- unsigned int i;
+ unsigned int i, nid = 0;
printk(KERN_DEBUG Top of RAM: 0x%lx, Total RAM: 0x%lx\n,
top_of_ram, total_ram);
@@ -471,9 +514,11 @@ static void __init setup_nonnuma(void)
for (i = 0; i lmb.memory.cnt; ++i) {
start_pfn = lmb.memory.region[i].base PAGE_SHIFT;
end_pfn = start_pfn +
Re: [PATCH] Fake NUMA emulation for PowerPC (Take 2)
On Sat, Dec 08, 2007 at 04:07:14AM +0530, Balbir Singh wrote: Signed-off-by: Balbir Singh [EMAIL PROTECTED] Looks good to me. Sure, it could be fleshed out to something more generic and in common code, but this is small and simple and doesn't bloat the kernel much as it stands, and it has value for debugging. Acked-by: Olof Johansson [EMAIL PROTECTED] ___ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
[PATCH] Fake NUMA emulation for PowerPC (Take 2)
Changelog
1. Get rid of the constant 5 (based on comments from
[EMAIL PROTECTED])
2. Implement suggestions from Olof Johannson
3. Check if cmdline is NULL in fake_numa_create_new_node()
Tested with additional parameters from Olof
numa=debug,fake=
numa=foo,fake=bar
Here's a dumb simple implementation of fake NUMA nodes for PowerPC. Fake
NUMA nodes can be specified using the following command line option
numa=fake=node range
node range is of the format range1,range2,...rangeN
Each of the rangeX parameters is passed using memparse(). I find the patch
useful for fake NUMA emulation on my simple PowerPC machine. I've tested it
on a non-numa box with the following arguments
numa=fake=1G
numa=fake=1G,2G
name=fake=1G,512M,2G
numa=fake=1500M,2800M mem=3500M
numa=fake=1G mem=512M
numa=fake=1G mem=1G
This patch applies on top of 2.6.24-rc4.
All though I've tried my best to handle some of the architecture specific
details of PowerPC, I might have overlooked something obvious, like the usage
of an API or some architecture tweaks. The patch depends on CONFIG_NUMA and
I decided against creating a separate config option for fake NUMA to keep
the code simple.
Comments are as always welcome!
Signed-off-by: Balbir Singh [EMAIL PROTECTED]
---
arch/powerpc/mm/numa.c | 59 -
1 file changed, 54 insertions(+), 5 deletions(-)
diff -puN arch/powerpc/mm/numa.c~ppc-fake-numa-easy arch/powerpc/mm/numa.c
--- linux-2.6.24-rc4-mm1/arch/powerpc/mm/numa.c~ppc-fake-numa-easy
2007-12-07 21:25:55.0 +0530
+++ linux-2.6.24-rc4-mm1-balbir/arch/powerpc/mm/numa.c 2007-12-08
03:19:46.0 +0530
@@ -24,6 +24,8 @@
static int numa_enabled = 1;
+static char *cmdline __initdata;
+
static int numa_debug;
#define dbg(args...) if (numa_debug) { printk(KERN_INFO args); }
@@ -39,6 +41,43 @@ static bootmem_data_t __initdata plat_no
static int min_common_depth;
static int n_mem_addr_cells, n_mem_size_cells;
+static int __cpuinit fake_numa_create_new_node(unsigned long end_pfn,
+ unsigned int *nid)
+{
+ unsigned long long mem;
+ char *p = cmdline;
+ static unsigned int fake_nid = 0;
+ static unsigned long long curr_boundary = 0;
+
+ *nid = fake_nid;
+ if (!p)
+ return 0;
+
+ mem = memparse(p, p);
+ if (!mem)
+ return 0;
+
+ if (mem curr_boundary)
+ return 0;
+
+ curr_boundary = mem;
+
+ if ((end_pfn PAGE_SHIFT) mem) {
+ /*
+* Skip commas and spaces
+*/
+ while (*p == ',' || *p == ' ' || *p == '\t')
+ p++;
+
+ cmdline = p;
+ fake_nid++;
+ *nid = fake_nid;
+ dbg(created new fake_node with id %d\n, fake_nid);
+ return 1;
+ }
+ return 0;
+}
+
static void __cpuinit map_cpu_to_node(int cpu, int node)
{
numa_cpu_lookup_table[cpu] = node;
@@ -344,12 +383,14 @@ static void __init parse_drconf_memory(s
if (nid == 0x || nid = MAX_NUMNODES)
nid = default_nid;
}
- node_set_online(nid);
size = numa_enforce_memory_limit(start, lmb_size);
if (!size)
continue;
+ fake_numa_create_new_node(((start + size) PAGE_SHIFT), nid);
+ node_set_online(nid);
+
add_active_range(nid, start PAGE_SHIFT,
(start PAGE_SHIFT) + (size PAGE_SHIFT));
}
@@ -429,7 +470,6 @@ new_range:
nid = of_node_to_nid_single(memory);
if (nid 0)
nid = default_nid;
- node_set_online(nid);
if (!(size = numa_enforce_memory_limit(start, size))) {
if (--ranges)
@@ -438,6 +478,9 @@ new_range:
continue;
}
+ fake_numa_create_new_node(((start + size) PAGE_SHIFT), nid);
+ node_set_online(nid);
+
add_active_range(nid, start PAGE_SHIFT,
(start PAGE_SHIFT) + (size PAGE_SHIFT));
@@ -461,7 +504,7 @@ static void __init setup_nonnuma(void)
unsigned long top_of_ram = lmb_end_of_DRAM();
unsigned long total_ram = lmb_phys_mem_size();
unsigned long start_pfn, end_pfn;
- unsigned int i;
+ unsigned int i, nid = 0;
printk(KERN_DEBUG Top of RAM: 0x%lx, Total RAM: 0x%lx\n,
top_of_ram, total_ram);
@@ -471,9 +514,11 @@ static void __init setup_nonnuma(void)
for (i = 0; i lmb.memory.cnt; ++i) {
start_pfn = lmb.memory.region[i].base PAGE_SHIFT;
end_pfn = start_pfn + lmb_size_pages(lmb.memory, i);
-
