From 1df21702873dab6ed95cfc5b7828553afd39fcde Mon Sep 17 00:00:00 2001 From: Alejandro Lucero Date: Fri, 5 Oct 2018 13:45:23 +0100 Subject: [PATCH] mem: use address hint for mapping hugepages Linux kernel uses a really high address as starting address for serving mmaps calls. If there exist 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 and increments the hint for next invocations. If the mmap call does not use the hint address, repeat the mmap call using the hint address incremented by page size. Signed-off-by: Alejandro Lucero Reviewed-by: Anatoly Burakov --- lib/librte_eal/common/eal_common_memory.c | 34 ++++++++++++++++++++++- 1 file changed, 33 insertions(+), 1 deletion(-) diff --git a/lib/librte_eal/common/eal_common_memory.c b/lib/librte_eal/common/eal_common_memory.c index a7559b99d3..12dcedf5c4 100644 --- a/lib/librte_eal/common/eal_common_memory.c +++ b/lib/librte_eal/common/eal_common_memory.c @@ -38,6 +38,23 @@ static void *next_baseaddr; static uint64_t system_page_sz; +#ifdef RTE_ARCH_64 +/* + * 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. + * + * Current known limitations are 39 or 40 bits. Setting the starting address + * at 4GB implies there are 508GB or 1020GB for mapping the available + * hugepages. This is likely enough for most systems, although a device with + * addressing limitations should call rte_eal_check_dma_mask for ensuring all + * memory is within supported range. + */ +static uint64_t baseaddr = 0x100000000; +#endif + void * eal_get_virtual_area(void *requested_addr, size_t *size, size_t page_sz, int flags, int mmap_flags) @@ -61,6 +78,11 @@ eal_get_virtual_area(void *requested_addr, size_t *size, rte_eal_process_type() == RTE_PROC_PRIMARY) next_baseaddr = (void *) internal_config.base_virtaddr; +#ifdef RTE_ARCH_64 + if (next_baseaddr == NULL && internal_config.base_virtaddr == 0 && + rte_eal_process_type() == RTE_PROC_PRIMARY) + next_baseaddr = (void *) baseaddr; +#endif if (requested_addr == NULL && next_baseaddr != NULL) { requested_addr = next_baseaddr; requested_addr = RTE_PTR_ALIGN(requested_addr, page_sz); @@ -92,7 +114,17 @@ eal_get_virtual_area(void *requested_addr, size_t *size, mmap_flags, -1, 0); if (mapped_addr == MAP_FAILED && allow_shrink) *size -= page_sz; - } while (allow_shrink && mapped_addr == MAP_FAILED && *size > 0); + + if (mapped_addr != MAP_FAILED && addr_is_hint && + mapped_addr != requested_addr) { + /* hint was not used. Try with another offset */ + munmap(mapped_addr, map_sz); + mapped_addr = MAP_FAILED; + next_baseaddr = RTE_PTR_ADD(next_baseaddr, page_sz); + requested_addr = next_baseaddr; + } + } while ((allow_shrink || addr_is_hint) && + mapped_addr == MAP_FAILED && *size > 0); /* align resulting address - if map failed, we will ignore the value * anyway, so no need to add additional checks. -- 2.20.1