Hi Dmitry, On 2022/10/11 23:58, Dmitry Kozlyuk wrote: > 2022-10-11 12:17 (UTC+0000), Chengwen Feng: > [...] >> diff --git a/doc/guides/prog_guide/memarea_lib.rst >> b/doc/guides/prog_guide/memarea_lib.rst >> new file mode 100644 >> index 0000000000..85ad57145f >> --- /dev/null >> +++ b/doc/guides/prog_guide/memarea_lib.rst >> @@ -0,0 +1,39 @@ >> +.. SPDX-License-Identifier: BSD-3-Clause >> + Copyright(c) 2022 HiSilicon Limited >> + >> +Memarea Library >> +=============== >> + >> +Introduction >> +------------ >> + >> +The memarea library provides an allocator of variable-size objects, it is >> +oriented towards the application layer, which could provides 'region-based >> +memory management' function [1]. >> + >> +The main features are as follows: >> + >> +* The allocated object aligned at ``RTE_CACHE_LINE_SIZE`` default. > > Isn't this an implementation detail? > Stating it in the API description limits optimization opportunities. > Cache line alignment is good in many cases, > but it can also be a waste of space, > e.g. for a thread-unsafe region for small objects. > Can this limitation only (temporarily?) apply to user memory? > Or can the minimal alignment be a property of memarea?
You are right, to be more general, I'll add the align parameter to rte_memarea_alloc instead of stating it here. > >> + >> +* The memory region can be initialized from the following memory sources: >> + a) HEAP: e.g. invoke ``rte_malloc_socket``. b) LIBC: e.g. invoke >> + posix_memalign to obtain. c) User memory: it can be from e.g. >> rte_extmem_xxx >> + as long as it is available. d) Another memarea: it can be allocated from >> + another memarea. > > I think mentioning rte_extmem_xxx() is bogus > because user memory does not need to be registered with DPDK > (I understand it's an example, but still an unrelated reference). > Please format as a list. okay > >> + >> +* It provides refcnt feature which could be useful in multi-reader scenario. >> + >> +* It supports MT-safe as long as it's specified at creation time. >> + >> +Library API Overview >> +-------------------- >> + >> +The ``rte_memarea_create()`` function is used to create a memarea, the >> function >> +returns the pointer to the created memarea or ``NULL`` if the creation >> failed. >> + >> +The ``rte_memarea_destroy()`` function is used to destroy a memarea. >> + >> +Reference >> +--------- >> + >> +[1] https://en.wikipedia.org/wiki/Region-based_memory_management >> diff --git a/doc/guides/rel_notes/release_22_11.rst >> b/doc/guides/rel_notes/release_22_11.rst >> index 2da8bc9661..f5a67cec7b 100644 >> --- a/doc/guides/rel_notes/release_22_11.rst >> +++ b/doc/guides/rel_notes/release_22_11.rst >> @@ -63,6 +63,12 @@ New Features >> In theory this implementation should work with any target based on >> ``LoongArch`` ISA. >> >> +* **Added memarea library.** >> + >> + The memarea library is an allocator of variable-size objects, it is >> oriented >> + towards the application layer, which could provides 'region-based memory >> + management' function. > > "which could provides" -> "providing" okay > >> + >> * **Added support for multiple mbuf pools per ethdev Rx queue.** >> >> The capability allows application to provide many mempools > [...] > . >
