On 02-Jul-18 6:27 PM, Alejandro Lucero wrote:
Linux kernel uses a really high address as starting address for
serving mmaps calls. If there exists addressing limitations and
IOVA mode is VA, this starting address is likely too high for
those devices. However, it is possible to use a lower address in
the process virtual address space as with 64 bits there is a lot
of available space.
This patch adds an address hint as starting address for 64 bits
systems.
Signed-off-by: Alejandro Lucero <alejandro.luc...@netronome.com>
---
<snip>
long aligned_addr;
- if (internal_config.base_virtaddr != 0) {
- addr = (void*) (uintptr_t) (internal_config.base_virtaddr +
- baseaddr_offset);
- }
- else addr = NULL;
-
RTE_LOG(DEBUG, EAL, "Ask a virtual area of 0x%zx bytes\n", *size);
fd = open("/dev/zero", O_RDONLY);
@@ -278,7 +289,22 @@
return NULL;
}
do {
- addr = mmap(addr,
+ if (internal_config.base_virtaddr != 0) {
+ addr_hint = (void *) (uintptr_t)
+ (internal_config.base_virtaddr +
+ baseaddr_offset);
+ }
+#ifdef RTE_ARCH_64
+ else {
+ addr_hint = (void *) (uintptr_t) (baseaddr +
+ baseaddr_offset);
+ }
+#else
+ else {
+ addr_hint = NULL;
+ }
+#endif
If my understanding is correct, calculations are all done on static
variables, only the result is assigned to addr_hint which is local. Can
we move this into a function and put these #ifdefs there, while keeping
this code clean?
+ addr = mmap(addr_hint,
(*size) + hugepage_sz, PROT_READ,
#ifdef RTE_ARCH_PPC_64
MAP_PRIVATE | MAP_ANONYMOUS | MAP_HUGETLB,
@@ -286,8 +312,14 @@
MAP_PRIVATE,
#endif
fd, 0);
- if (addr == MAP_FAILED)
+ if (addr == MAP_FAILED) {
+ /* map failed. Let's try with less memory */
*size -= hugepage_sz;
+ } else if (addr_hint && addr != addr_hint) {
+ /* map not using hint. Let's try with another offset */
Comment is slightly misleading - "map not using hint" implies we are
about to map something without using hint. Suggested rewording:
suggested address hint was not used, try with another offset
+ addr = MAP_FAILED;
+ baseaddr_offset += 0x100000000;
+ }
} while (addr == MAP_FAILED && *size > 0);
if (addr == MAP_FAILED) {
--
Thanks,
Anatoly
