The stack library was first released in 19.05, and its interfaces have been
stable since their initial introduction. This commit promotes the full
interface to stable, starting with the 20.11 major version.
Signed-off-by: Gage Eads <gage.eads@intel.com>
Acked-by: David Marchand <david.marchand@redhat.com>
This patch fixes an issue that uninitialized 'success'
is used to be compared with '0'.
Coverity issue: 337676
Fixes: 3340202f59 ("stack: add lock-free implementation")
Cc: stable@dpdk.org
Signed-off-by: Yunjian Wang <wangyunjian@huawei.com>
Reviewed-by: David Marchand <david.marchand@redhat.com>
Replace the store-release by relaxed for the CAS success at the end of
pop. Release isn't needed, because there is not write to data that need
to be synchronized.
The only preceding write is when the length is decreased, but the length
CAS loop already ensures the right synchronization.
The situation to avoid is when a thread sees the old length but the new
list, that doesn't have enough items for pop to success.
But the CAS success on length before the pop loop ensures any core reads
and updates the latest length, preventing this situation.
The store-release is also used to make sure that the items are read
before the head is updated, in order to prevent a core in pop to read an
incorrect value because another core rewrites it with push.
But this isn't needed, because items are read only when removed from the
used list. Right after this, they are pushed to the free list, and the
store-release in push makes sure the items are read before they are
visible in the free list.
Signed-off-by: Steven Lariau <steven.lariau@arm.com>
Reviewed-by: Dharmik Thakkar <dharmik.thakkar@arm.com>
Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
Acked-by: Gage Eads <gage.eads@intel.com>
List head must be loaded right before continue (when failed to
find the new head).
Without this, one thread might keep trying and failing to pop items
without ever loading the new correct head.
Fixes: 7e6e609939 ("stack: add C11 atomic implementation")
Cc: gage.eads@intel.com
Cc: stable@dpdk.org
Signed-off-by: Steven Lariau <steven.lariau@arm.com>
Reviewed-by: Dharmik Thakkar <dharmik.thakkar@arm.com>
Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
Acked-by: Gage Eads <gage.eads@intel.com>
The load-acquire of list->len on pop function is redundant.
Only the CAS success needs to be load-acquire.
It synchronizes with the store release in push, to ensure that the
updated head is visible when the new length is visible.
Without this, one thread in pop could see the increased length but the
old list, which doesn't have enough items yet for pop to succeed.
Signed-off-by: Steven Lariau <steven.lariau@arm.com>
Reviewed-by: Dharmik Thakkar <dharmik.thakkar@arm.com>
Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
Acked-by: Gage Eads <gage.eads@intel.com>
An acquire fence is used to make sure loads after the fence can observe
all store operations before a specific store-release.
But push doesn't read any data, except for the head which is part of a
CAS operation (the items on the list are not read).
So there is no need for the acquire barrier.
Signed-off-by: Steven Lariau <steven.lariau@arm.com>
Reviewed-by: Dharmik Thakkar <dharmik.thakkar@arm.com>
Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
Acked-by: Gage Eads <gage.eads@intel.com>
Fix cmpexchange usage of weak / strong.
The generated code is the same on x86 and ARM (there is no weak
cmpexchange), but the old usage was inconsistent.
For push and pop update size, weak is used because cmpexchange is inside
a loop.
For pop update root, strong is used even though cmpexchange is inside a
loop, because there may be a lot of operations to do in a loop iteration
(locate the new head).
Signed-off-by: Steven Lariau <steven.lariau@arm.com>
Reviewed-by: Dharmik Thakkar <dharmik.thakkar@arm.com>
Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
Acked-by: Gage Eads <gage.eads@intel.com>
A decision was made [1] to no longer support Make in DPDK, this patch
removes all Makefiles that do not make use of pkg-config, along with
the mk directory previously used by make.
[1] https://mails.dpdk.org/archives/dev/2020-April/162839.html
Signed-off-by: Ciara Power <ciara.power@intel.com>
Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
Signed-off-by: Thomas Monjalon <thomas@monjalon.net>
The following libraries are experimental, all of their functions can
be changed or removed:
- librte_bbdev
- librte_bpf
- librte_compressdev
- librte_fib
- librte_flow_classify
- librte_graph
- librte_ipsec
- librte_node
- librte_rcu
- librte_rib
- librte_stack
- librte_telemetry
Their status is properly announced in MAINTAINERS.
Remind this status in their headers in a common fashion (aligned to ABI
docs).
Cc: stable@dpdk.org
Signed-off-by: David Marchand <david.marchand@redhat.com>
Acked-by: Bruce Richardson <bruce.richardson@intel.com>
Introduce the RTE_LOG_REGISTER macro to avoid the code duplication
in the logtype registration process.
It is a wrapper macro for declaring the logtype, registering it and
setting its level in the constructor context.
Signed-off-by: Jerin Jacob <jerinj@marvell.com>
Acked-by: Adam Dybkowski <adamx.dybkowski@intel.com>
Acked-by: Sachin Saxena <sachin.saxena@nxp.com>
Acked-by: Akhil Goyal <akhil.goyal@nxp.com>
All API's should check that they support the flag values
passed. If an application passes an invalid flag it could
cause problems in later ABI.
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Acked-by: Bruce Richardson <bruce.richardson@intel.com>
Acked-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
Acked-by: Gage Eads <gage.eads@intel.com>
Remove setting ALLOW_EXPERIMENTAL_API individually for each Makefile and
meson.build. Instead, enable ALLOW_EXPERIMENTAL_API flag across app, lib
and drivers.
This changes reduces the clutter across the project while still
maintaining the functionality of ALLOW_EXPERIMENTAL_API i.e. warning
external applications about experimental API usage.
Signed-off-by: Pavan Nikhilesh <pbhagavatula@marvell.com>
Acked-by: Hemant Agrawal <hemant.agrawal@nxp.com>
Signed-off-by: David Marchand <david.marchand@redhat.com>
Since the library versioning for both stable and experimental ABI's is
now managed globally, the LIBABIVER and version variables no longer
serve any useful purpose, and can be removed.
The replacement in Makefiles was done using the following regex:
^(#.*\n)?LIBABIVER\s*:=\s*\d+\n(\s*\n)?
(LIBABIVER := numbers, optionally preceded by a comment and optionally
succeeded by an empty line)
The replacement for meson files was done using the following regex:
^(#.*\n)?version\s*=\s*\d+\n(\s*\n)?
(version = numbers, optionally preceded by a comment and optionally
succeeded by an empty line)
[David]: those variables are manually removed for the files:
- drivers/common/qat/Makefile
- lib/librte_eal/meson.build
[David]: the LIBABIVER is restored for the external ethtool example
library.
Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
Signed-off-by: David Marchand <david.marchand@redhat.com>
Acked-by: Thomas Monjalon <thomas@monjalon.net>
Some of the internal header files have 'rte_' prefix
and some don't.
Remove 'rte_' prefix from all internal header files.
Suggested-by: Thomas Monjalon <thomas@monjalon.net>
Signed-off-by: Dharmik Thakkar <dharmik.thakkar@arm.com>
Reviewed-by: Phil Yang <phil.yang@arm.com>
Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
Enable both C11 atomic and non C11 atomic lock-free stack for aarch64.
Introduced a new header to reduce the ifdef clutter across generic and C11
files. The rte_stack_lf_stubs.h contains stub implementations of
__rte_stack_lf_count, __rte_stack_lf_push_elems and
__rte_stack_lf_pop_elems.
Suggested-by: Gage Eads <gage.eads@intel.com>
Suggested-by: Jerin Jacob <jerinj@marvell.com>
Signed-off-by: Phil Yang <phil.yang@arm.com>
Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
Tested-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
Acked-by: Jerin Jacob <jerinj@marvell.com>
Currently, locking/unlocking the TAILQ list requires direct
access to the shared memory config. Add an API to do the same,
and search-and-replace all usages.
Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
Acked-by: Stephen Hemminger <stephen@networkplumber.org>
Acked-by: David Marchand <david.marchand@redhat.com>
Putting a '__attribute__((deprecated))' in the middle of a function
prototype does not result in the expected result with gcc (while clang
is fine with this syntax).
$ cat deprecated.c
void * __attribute__((deprecated)) incorrect() { return 0; }
__attribute__((deprecated)) void *correct(void) { return 0; }
int main(int argc, char *argv[]) { incorrect(); correct(); return 0; }
$ gcc -o deprecated.o -c deprecated.c
deprecated.c: In function ‘main’:
deprecated.c:3:1: warning: ‘correct’ is deprecated (declared at
deprecated.c:2) [-Wdeprecated-declarations]
int main(int argc, char *argv[]) { incorrect(); correct(); return 0; }
^
Move the tag on a separate line and make it the first thing of function
prototypes.
This is not perfect but we will trust reviewers to catch the other not
so easy to detect patterns.
sed -i \
-e '/^\([^#].*\)\?__rte_experimental */{' \
-e 's//\1/; s/ *$//; i\' \
-e __rte_experimental \
-e '/^$/d}' \
$(git grep -l __rte_experimental -- '*.h')
Special mention for rte_mbuf_data_addr_default():
There is either a bug or a (not yet understood) issue with gcc.
gcc won't drop this inline when unused and rte_mbuf_data_addr_default()
calls rte_mbuf_buf_addr() which itself is experimental.
This results in a build warning when not accepting experimental apis
from sources just including rte_mbuf.h.
For this specific case, we hide the call to rte_mbuf_buf_addr() under
the ALLOW_EXPERIMENTAL_API flag.
Signed-off-by: Adrien Mazarguil <adrien.mazarguil@6wind.com>
Signed-off-by: David Marchand <david.marchand@redhat.com>
clang raise 'pointer-sign' warnings in __atomic_compare_exchange
when passing 'uint64_t *' to parameter of type 'int64_t *' converts
between pointers to integer types with different sign.
Fixes: 7e6e609939 ("stack: add C11 atomic implementation")
Cc: stable@dpdk.org
Suggested-by: Gage Eads <gage.eads@intel.com>
Signed-off-by: Phil Yang <phil.yang@arm.com>
Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
Reviewed-by: Gavin Hu <gavin.hu@arm.com>
Acked-by: Gage Eads <gage.eads@intel.com>
Do a global replace of snprintf(..."%s",...) with strlcpy, adding in the
rte_string_fns.h header if needed. The function changes in this patch were
auto-generated via command:
spatch --sp-file devtools/cocci/strlcpy.cocci --dir . --in-place
and then the files edited using awk to add in the missing header:
gawk -i inplace '/include <rte_/ && ! seen { \
print "#include <rte_string_fns.h>"; seen=1} {print}'
Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
This commit adds an implementation of the lock-free stack push, pop, and
length functions that use __atomic builtins, for systems that benefit from
the finer-grained memory ordering control.
Signed-off-by: Gage Eads <gage.eads@intel.com>
Reviewed-by: Olivier Matz <olivier.matz@6wind.com>
Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
This commit adds support for a lock-free (linked list based) stack to the
stack API. This behavior is selected through a new rte_stack_create() flag,
RTE_STACK_F_LF.
The stack consists of a linked list of elements, each containing a data
pointer and a next pointer, and an atomic stack depth counter.
The lock-free push operation enqueues a linked list of pointers by pointing
the tail of the list to the current stack head, and using a CAS to swing
the stack head pointer to the head of the list. The operation retries if it
is unsuccessful (i.e. the list changed between reading the head and
modifying it), else it adjusts the stack length and returns.
The lock-free pop operation first reserves num elements by adjusting the
stack length, to ensure the dequeue operation will succeed without
blocking. It then dequeues pointers by walking the list -- starting from
the head -- then swinging the head pointer (using a CAS as well). While
walking the list, the data pointers are recorded in an object table.
This algorithm stack uses a 128-bit compare-and-swap instruction, which
atomically updates the stack top pointer and a modification counter, to
protect against the ABA problem.
The linked list elements themselves are maintained in a lock-free LIFO
list, and are allocated before stack pushes and freed after stack pops.
Since the stack has a fixed maximum depth, these elements do not need to be
dynamically created.
Signed-off-by: Gage Eads <gage.eads@intel.com>
Reviewed-by: Olivier Matz <olivier.matz@6wind.com>
Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
The rte_stack library provides an API for configuration and use of a
bounded stack of pointers. Push and pop operations are MT-safe, allowing
concurrent access, and the interface supports pushing and popping multiple
pointers at a time.
The library's interface is modeled after another DPDK data structure,
rte_ring, and its lock-based implementation is derived from the stack
mempool handler. An upcoming commit will migrate the stack mempool handler
to rte_stack.
Signed-off-by: Gage Eads <gage.eads@intel.com>
Reviewed-by: Olivier Matz <olivier.matz@6wind.com>
Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
