diff options
Diffstat (limited to 'drivers/misc/sgi-xp/xp.h')
-rw-r--r-- | drivers/misc/sgi-xp/xp.h | 11 |
1 files changed, 3 insertions, 8 deletions
diff --git a/drivers/misc/sgi-xp/xp.h b/drivers/misc/sgi-xp/xp.h index 955b5b913235..0ca81f16646f 100644 --- a/drivers/misc/sgi-xp/xp.h +++ b/drivers/misc/sgi-xp/xp.h | |||
@@ -21,7 +21,7 @@ | |||
21 | #include <asm/sn/arch.h> | 21 | #include <asm/sn/arch.h> |
22 | #endif | 22 | #endif |
23 | 23 | ||
24 | /* >>> Add this #define to some linux header file some day. */ | 24 | /* ??? Add this #define to some linux header file some day? */ |
25 | #define BYTES_PER_WORD sizeof(void *) | 25 | #define BYTES_PER_WORD sizeof(void *) |
26 | 26 | ||
27 | #ifdef USE_DBUG_ON | 27 | #ifdef USE_DBUG_ON |
@@ -65,18 +65,13 @@ | |||
65 | * other partition that is currently up. Over these channels, kernel-level | 65 | * other partition that is currently up. Over these channels, kernel-level |
66 | * `users' can communicate with their counterparts on the other partitions. | 66 | * `users' can communicate with their counterparts on the other partitions. |
67 | * | 67 | * |
68 | >>> The following described limitation of a max of eight channels possible | ||
69 | >>> pertains only to ia64-sn2. THIS ISN'T TRUE SINCE I'M PLANNING TO JUST | ||
70 | >>> TIE INTO THE EXISTING MECHANISM ONCE THE CHANNEL MESSAGES ARE RECEIVED. | ||
71 | >>> THE 128-BYTE CACHELINE PERFORMANCE ISSUE IS TIED TO IA64-SN2. | ||
72 | * | ||
73 | * If the need for additional channels arises, one can simply increase | 68 | * If the need for additional channels arises, one can simply increase |
74 | * XPC_MAX_NCHANNELS accordingly. If the day should come where that number | 69 | * XPC_MAX_NCHANNELS accordingly. If the day should come where that number |
75 | * exceeds the absolute MAXIMUM number of channels possible (eight), then one | 70 | * exceeds the absolute MAXIMUM number of channels possible (eight), then one |
76 | * will need to make changes to the XPC code to accommodate for this. | 71 | * will need to make changes to the XPC code to accommodate for this. |
77 | * | 72 | * |
78 | * The absolute maximum number of channels possible is currently limited to | 73 | * The absolute maximum number of channels possible is limited to eight for |
79 | * eight for performance reasons. The internal cross partition structures | 74 | * performance reasons on sn2 hardware. The internal cross partition structures |
80 | * require sixteen bytes per channel, and eight allows all of this | 75 | * require sixteen bytes per channel, and eight allows all of this |
81 | * interface-shared info to fit in one 128-byte cacheline. | 76 | * interface-shared info to fit in one 128-byte cacheline. |
82 | */ | 77 | */ |