On 25-May-20 1:37 AM, Dmitry Kozlyuk wrote:
Introduce OS-independent wrappers for memory management operations used
across DPDK and specifically in common code of EAL:
* rte_mem_map()
* rte_mem_unmap()
* rte_get_page_size()
* rte_mem_lock()
Windows uses different APIs for memory mapping and reservation, while
Unices reserve memory by mapping it. Introduce EAL private functions to
support memory reservation in common code:
* eal_mem_reserve()
* eal_mem_free()
* eal_mem_set_dump()
Wrappers follow POSIX semantics limited to DPDK tasks, but their
signatures deliberately differ from POSIX ones to be more safe and
expressive.
Signed-off-by: Dmitry Kozlyuk <dmitry.kozl...@gmail.com>
---
<snip>
- page_sz = sysconf(_SC_PAGESIZE);
+ page_sz = rte_get_page_size();
if (page_sz == (size_t)-1) {
free(ma);
return -1;
@@ -754,9 +751,11 @@ rte_fbarray_init(struct rte_fbarray *arr, const char
*name, unsigned int len,
if (internal_config.no_shconf) {
/* remap virtual area as writable */
- void *new_data = mmap(data, mmap_len, PROT_READ | PROT_WRITE,
- MAP_FIXED | MAP_PRIVATE | MAP_ANONYMOUS, fd, 0);
- if (new_data == MAP_FAILED) {
+ static const int flags = RTE_MAP_FORCE_ADDRESS |
+ RTE_MAP_PRIVATE | RTE_MAP_ANONYMOUS;
+ void *new_data = rte_mem_map(data, mmap_len,
+ RTE_PROT_READ | RTE_PROT_WRITE, flags, fd, 0);
+ if (new_data == NULL) {
RTE_LOG(DEBUG, EAL, "%s(): couldn't remap anonymous memory:
%s\n",
__func__, strerror(errno));
I believe this should be rte_strerror(rte_errno) instead of strerror(errno).
goto fail;
@@ -821,7 +820,7 @@ rte_fbarray_init(struct rte_fbarray *arr, const char *name,
unsigned int len,
return 0;
fail:
if (data)
- munmap(data, mmap_len);
+ rte_mem_unmap(data, mmap_len);
if (fd >= 0)
close(fd);
free(ma);
@@ -859,7 +858,7 @@ rte_fbarray_attach(struct rte_fbarray *arr)
return -1;
<snip>
+/**
+ * Memory protection flags.
+ */
+enum rte_mem_prot {
+ RTE_PROT_READ = 1 << 0, /**< Read access. */
+ RTE_PROT_WRITE = 1 << 1, /**< Write access. */
+ RTE_PROT_EXECUTE = 1 << 2 /**< Code execution. */
+};
+
+/**
+ * Additional flags for memory mapping.
+ */
+enum rte_map_flags {
+ /** Changes to the mapped memory are visible to other processes. */
+ RTE_MAP_SHARED = 1 << 0,
+ /** Mapping is not backed by a regular file. */
+ RTE_MAP_ANONYMOUS = 1 << 1,
+ /** Copy-on-write mapping, changes are invisible to other processes. */
+ RTE_MAP_PRIVATE = 1 << 2,
+ /**
+ * Force mapping to the requested address. This flag should be used
+ * with caution, because to fulfill the request implementation
+ * may remove all other mappings in the requested region. However,
+ * it is not required to do so, thus mapping with this flag may fail.
+ */
+ RTE_MAP_FORCE_ADDRESS = 1 << 3
+};
I have no strong opinion on this, but it feels like the fact that these
are enums is a relic from the times where you used enum everywhere :) i
have a feeling that DPDK codebase prefers #define's for this usage,
while what you have here is more of a C++ thing.
--
Thanks,
Anatoly
