On 4/16/2015 3:41 PM, David Miller wrote:
From: David Miller <davem@xxxxxxxxxxxxx>
Date: Thu, 09 Apr 2015 19:06:47 -0400 (EDT)
How will this work on T3, T2, and T1 which all neither have the
"socket" mdesc nodes nor level 3 caches?
I'm still waiting for you to resolve this Chris.
I don't think it's much effort to make this change back down
to using the level=2 cache if no level=3 cache is found. Please
implement that and resubmit.
So that does appear to work. This is not the patch. I will send that out shortly but I thought I'd give you a chance to
provide feedback while I'm getting that ready.
Here is what I see on a T2.
before:
-----------------
tct2000-52> lscpu
Architecture: sparc64
CPU op-mode(s): 32-bit, 64-bit
Byte Order: Big Endian
CPU(s): 32
On-line CPU(s) list: 0-31
Thread(s) per core: 4
Core(s) per socket: 1
Socket(s): 8
after:
----------------------
tct2000-52> lscpu
Architecture: sparc64
CPU op-mode(s): 32-bit, 64-bit
Byte Order: Big Endian
CPU(s): 32
On-line CPU(s) list: 0-31
Thread(s) per core: 4
Core(s) per socket: 8
Socket(s): 1
Diff from the prior patch (I also see some cleanup here I will do):
diff --git a/arch/sparc/kernel/mdesc.c b/arch/sparc/kernel/mdesc.c
index 78beb94..75e2890 100644
--- a/arch/sparc/kernel/mdesc.c
+++ b/arch/sparc/kernel/mdesc.c
@@ -694,23 +694,26 @@ static void set_core_ids(struct mdesc_handle *hp)
}
}
-static void set_sock_ids_by_cache(struct mdesc_handle *hp, u64 mp)
+static int set_sock_ids_by_cache(struct mdesc_handle *hp, u64 mp, int level)
{
int idx = 1;
+ int fnd = 0;
/* Identify unique sockets by looking for cpus backpointed to by
- * level 3 caches.
+ * shared level n caches.
*/
mdesc_for_each_node_by_name(hp, mp, "cache") {
- const u64 *level;
+ const u64 *cur_lvl;
- level = mdesc_get_property(hp, mp, "level", NULL);
- if (*level != 3)
+ cur_lvl = mdesc_get_property(hp, mp, "level", NULL);
+ if (*cur_lvl != level)
continue;
mark_sock_ids(hp, mp, idx);
idx++;
+ fnd = 1;
}
+ return fnd;
}
static void set_sock_ids_by_socket(struct mdesc_handle *hp, u64 mp)
@@ -742,11 +745,12 @@ static void set_sock_ids(struct mdesc_handle *hp)
u64 mp;
/* If machine description exposes sockets data use it.
- * Otherwise fallback to use L3 cache
+ * Otherwise fallback to use shared L3 or L2 caches
*/
mp = mdesc_node_by_name(hp, MDESC_NODE_NULL, "sockets");
if (mp == MDESC_NODE_NULL)
- return set_sock_ids_by_cache(hp, mp);
+ if (!set_sock_ids_by_cache(hp, mp, 3))
+ set_sock_ids_by_cache(hp, mp, 2);
return set_sock_ids_by_socket(hp, mp);
}
--
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