diff options
| -rw-r--r-- | arch/ia64/include/asm/io.h | 24 |
1 files changed, 0 insertions, 24 deletions
diff --git a/arch/ia64/include/asm/io.h b/arch/ia64/include/asm/io.h index 7f257507cd86..0d9d16e2d949 100644 --- a/arch/ia64/include/asm/io.h +++ b/arch/ia64/include/asm/io.h | |||
| @@ -434,28 +434,4 @@ extern void memset_io(volatile void __iomem *s, int c, long n); | |||
| 434 | 434 | ||
| 435 | # endif /* __KERNEL__ */ | 435 | # endif /* __KERNEL__ */ |
| 436 | 436 | ||
| 437 | /* | ||
| 438 | * Enabling BIO_VMERGE_BOUNDARY forces us to turn off I/O MMU bypassing. It is said that | ||
| 439 | * BIO-level virtual merging can give up to 4% performance boost (not verified for ia64). | ||
| 440 | * On the other hand, we know that I/O MMU bypassing gives ~8% performance improvement on | ||
| 441 | * SPECweb-like workloads on zx1-based machines. Thus, for now we favor I/O MMU bypassing | ||
| 442 | * over BIO-level virtual merging. | ||
| 443 | */ | ||
| 444 | extern unsigned long ia64_max_iommu_merge_mask; | ||
| 445 | #if 1 | ||
| 446 | #define BIO_VMERGE_BOUNDARY 0 | ||
| 447 | #else | ||
| 448 | /* | ||
| 449 | * It makes no sense at all to have this BIO_VMERGE_BOUNDARY macro here. Should be | ||
| 450 | * replaced by dma_merge_mask() or something of that sort. Note: the only way | ||
| 451 | * BIO_VMERGE_BOUNDARY is used is to mask off bits. Effectively, our definition gets | ||
| 452 | * expanded into: | ||
| 453 | * | ||
| 454 | * addr & ((ia64_max_iommu_merge_mask + 1) - 1) == (addr & ia64_max_iommu_vmerge_mask) | ||
| 455 | * | ||
| 456 | * which is precisely what we want. | ||
| 457 | */ | ||
| 458 | #define BIO_VMERGE_BOUNDARY (ia64_max_iommu_merge_mask + 1) | ||
| 459 | #endif | ||
| 460 | |||
| 461 | #endif /* _ASM_IA64_IO_H */ | 437 | #endif /* _ASM_IA64_IO_H */ |
