On 03-Jul-18 1:09 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>
+static void *
+get_addr_hint(void)
+{
+ if (internal_config.base_virtaddr != 0) {
+ return (void *) (uintptr_t)
+ (internal_config.base_virtaddr +
+ baseaddr_offset);
+ }
+#ifdef RTE_ARCH_64
+ else {
+ return (void *) (uintptr_t) (baseaddr +
+ baseaddr_offset);
+ }
+#else
+ else {
+ return NULL;
+ }
+#endif
Nitpicking, but probably ifdefs should be inside else clause? Two else's
look weird.
+}
+
/*
* Try to mmap *size bytes in /dev/zero. If it is successful, return the
* pointer to the mmap'd area and keep *size unmodified. Else, retry
@@ -260,16 +297,10 @@
static void *
get_virtual_area(size_t *size, size_t hugepage_sz)
{
<snip>
- addr = mmap(addr,
+ addr_hint = get_addr_hint();
+
+ addr = mmap(addr_hint,
(*size) + hugepage_sz, PROT_READ,
#ifdef RTE_ARCH_PPC_64
MAP_PRIVATE | MAP_ANONYMOUS | MAP_HUGETLB,
@@ -286,8 +319,15 @@
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) {
+ /* hint was not used. Try with another offset */
+ munmap(addr, (*size) + hugepage_sz);
Maybe store mapping size in a variable.
Otherwise,
Acked-by: Anatoly Burakov <anatoly.bura...@intel.com>
--
Thanks,
Anatoly
