To verify that all DPDK headers are ok for inclusion directly in a C file,
and are not missing any other pre-requisite headers, we can auto-generate
for each header an empty C file that includes that header. Compiling these
files will throw errors if any header has unmet dependencies.
For some libraries, there may be some header files which are not for direct
inclusion, but rather are to be included via other header files. To allow
later checking of these files for missing includes, we separate out the
indirect include files from the direct ones.
To ensure ongoing compliance, we enable this build test as part of the
default x86 build in "test-meson-builds.sh".
Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
For legacy modes, rename ring_generic/c11 to ring_generic/c11_pvt.
Furthermore, add new file ring_elem_pvt.h which includes ring_do_eq/deq
and ring element copy/delete APIs.
The update_tail internal helper has been prefixed with the library prefix.
For other modes, rename xx_c11_mem to xx_elem_pvt. Move all private APIs
into these new header files.
Finally, the external APIs and internal APIs will be separated from each
other. This can remind users not to use internal APIs and make ring
library easier to maintain.
Suggested-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
Signed-off-by: Feifei Wang <feifei.wang2@arm.com>
Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
Acked-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
Add zero-copy APIs. These APIs provide the capability to
copy the data to/from the ring memory directly, without
having a temporary copy (for ex: an array of mbufs on
the stack). Use cases that involve copying large amount
of data to/from the ring can benefit from these APIs.
Signed-off-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
Reviewed-by: Dharmik Thakkar <dharmik.thakkar@arm.com>
Acked-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
Since each version map file is contained in the subdirectory of the library
it refers to, there is no need to include the library name in the filename.
This makes things simpler in case of library renaming.
Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
Acked-by: Luca Boccassi <bluca@debian.org>
Acked-by: Andrew Rybchenko <andrew.rybchenko@oktetlabs.ru>
Acked-by: Rosen Xu <rosen.xu@intel.com>
Make is not supported for compiling DPDK, the config files are no
longer needed.
Signed-off-by: Ciara Power <ciara.power@intel.com>
Signed-off-by: Thomas Monjalon <thomas@monjalon.net>
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>
Start a new release cycle with empty release notes.
The ABI version becomes 21.0.
The ABI major is back to normal, having only one number (21 vs 20.0).
The map files are updated to the new ABI major number (21).
The ABI exceptions are dropped.
Travis ABI check is disabled because compatibility is not preserved.
Signed-off-by: Thomas Monjalon <thomas@monjalon.net>
Acked-by: Ray Kinsella <mdr@ashroe.eu>
Use rte_ring_xxx_elem_xxx APIs to replace legacy API implementation.
This reduces code duplication and improves code maintenance.
Tests done on Arm, x86 [1] and PPC [2] do not indicate performance
degradation.
[1] https://mails.dpdk.org/archives/dev/2020-July/173780.html
[2] https://mails.dpdk.org/archives/dev/2020-July/173863.html
Signed-off-by: Feifei Wang <feifei.wang2@arm.com>
Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
Tested-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
Tested-by: David Christensen <drc@linux.vnet.ibm.com>
Acked-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
Remove the experimental tag for rte_ring_xxx_elem APIs that have been
around for 2 releases.
Signed-off-by: Feifei Wang <feifei.wang2@arm.com>
Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
Acked-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
Remove the experimental tag for rte_ring_reset API that have been around
for 4 releases.
Signed-off-by: Feifei Wang <feifei.wang2@arm.com>
Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
Testing if the ring is empty is as simple as comparing the producer and
consumer pointers.
In theory, this optimization reduces the number of potential cache misses
from 3 to 2 by not having to read r->mask in rte_ring_count().
The modification of this function were also discussed in the RFC here:
https://mails.dpdk.org/archives/dev/2020-April/165752.html
Signed-off-by: Morten Brørup <mb@smartsharesystems.com>
Acked-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
Fix coding style violations that checkpatch will complain about.
Add missing "int" after "unsigned".
Add missing spaces around "+=" and "+".
Remove superfluous type cast of numerical constant.
Suggested-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
Signed-off-by: Morten Brørup <mb@smartsharesystems.com>
Acked-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
The value of *tail should be the prod->tail not prod->head. After
modification, it can record 'tail' so head/tail can be updated
accordingly.
Fixes: 664ff4b172 ("ring: introduce peek style API")
Signed-off-by: Feifei Wang <feifei.wang2@arm.com>
Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
Acked-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
Remove the unwanted call to "_rte_ring_do_enqueue_elem" to allow for
correct handling of RTS/HTS modes.
Fixes: e6ba4731c0 ("ring: introduce RTS ring mode")
Signed-off-by: Feifei Wang <feifei.wang2@arm.com>
Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
Acked-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
Acked-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
All API's should check that they support the flag values passed.
These checks ensure that the extra bits can safely be used
without risk of ABI breakage.
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
Acked-by: Bruce Richardson <bruce.richardson@intel.com>
Acked-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
Can be reproduced with "make EXTRA_CFLAGS='-O1'" command using
gcc (GCC) 9.3.1 20200408 (Red Hat 9.3.1-2)
Two build errors:
1)
In file included from .../build/include/rte_ring_elem.h:1093,
from .../lib/librte_rcu/rte_rcu_qsbr.c:21:
../lib/librte_rcu/rte_rcu_qsbr.c: In function ‘rte_rcu_qsbr_dq_reclaim’:
.../build/include/rte_ring_peek.h:282:22:
error: ‘avail’ may be used uninitialized in this function
[-Werror=maybe-uninitialized]
282 | *available = avail - n;
| ~~~~~~^~~
./build/include/rte_ring_peek.h:259:11: note: ‘avail’ was declared here
259 | uint32_t avail, head, next;
| ^~~~~
2)
In file included from .../build/include/rte_ring_elem.h:1093,
from .../build/include/rte_ring.h:405,
from .../app/test/test_ring_stress.h:13,
from .../app/test/test_ring_stress_impl.h:5,
from .../app/test/test_ring_peek_stress.c:5:
.../app/test/test_ring_peek_stress.c: In function ‘_st_ring_enqueue_bulk’:
.../build/include/rte_ring_peek.h:80:22:
error: ‘free’ may be used uninitialized in this function
[-Werror=maybe-uninitialized]
80 | *free_space = free - n;
| ~~~~~^~~
.../build/include/rte_ring_peek.h:60:11: note: ‘free’ was declared here
60 | uint32_t free, head, next;
| ^~~~
The cases shouldn't be hit, and it looks like there is already logic
error if it has been hit, but assigning 'avail' & 'free' to '0' to fix
the build error.
Signed-off-by: Ferruh Yigit <ferruh.yigit@intel.com>
Acked-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
Some popular vswitch implementation might use a gcc option that
complains about missing enums in switch statements.
Fix this by listing all possible values.
Fixes: 664ff4b172 ("ring: introduce peek style API")
Signed-off-by: David Marchand <david.marchand@redhat.com>
Acked-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
For rings with producer/consumer in RTE_RING_SYNC_ST, RTE_RING_SYNC_MT_HTS
mode, provide an ability to split enqueue/dequeue operation
into two phases:
- enqueue/dequeue start
- enqueue/dequeue finish
That allows user to inspect objects in the ring without removing
them from it (aka MT safe peek).
Signed-off-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
Acked-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
Introduce head/tail sync mode for MT ring synchronization.
In that mode enqueue/dequeue operation is fully serialized:
only one thread at a time is allowed to perform given op.
Suppose to reduce stall times in case when ring is used on
overcommitted cpus (multiple active threads on the same cpu).
Signed-off-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
Acked-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
Introduce relaxed tail sync (RTS) mode for MT ring synchronization.
Aim to reduce stall times in case when ring is used on
overcommited cpus (multiple active threads on the same cpu).
The main difference from original MP/MC algorithm is that
tail value is increased not by every thread that finished enqueue/dequeue,
but only by the last one.
That allows threads to avoid spinning on ring tail value,
leaving actual tail value change to the last thread in the update queue.
Signed-off-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
Acked-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
To make these preparations two main things are done:
- Change from *single* to *sync_type* to allow different
synchronisation schemes to be applied.
Mark *single* as deprecated in comments.
Add new functions to allow user to query ring sync types.
Replace direct access to *single* with appropriate function call.
- Move actual rte_ring and related structures definitions into a
separate file: <rte_ring_core.h>. It allows to refer contents
of <rte_ring_elem.h> from <rte_ring.h> without introducing a
circular dependency.
Signed-off-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
Acked-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.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>
The 32-bit arm machine doesn't support unaligned memory access. It
will cause a bus error on aarch32 with the custom element size ring.
Thread 1 "test" received signal SIGBUS, Bus error.
__rte_ring_enqueue_elems_64 (n=1, obj_table=0xf5edfe41, prod_head=0, \
r=0xf5edfb80) at /build/dpdk/build/include/rte_ring_elem.h:177
177 ring[idx++] = obj[i++];
Fixes: cc4b218790 ("ring: support configurable element size")
Signed-off-by: Phil Yang <phil.yang@arm.com>
Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
Correct the documentation for obj_table in rte_ring_xxx_elem APIs.
Fixes: cc4b218790 ("ring: support configurable element size")
Signed-off-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
Reviewed-by: Gavin Hu <gavin.hu@arm.com>
When adding custom element size feature, some internal inline functions
were added in a public header without rte_ prefix.
It is fixed by adding __rte_ring_.
Fixes: cc4b218790 ("ring: support configurable element size")
Reported-by: David Marchand <david.marchand@redhat.com>
Signed-off-by: Thomas Monjalon <thomas@monjalon.net>
Acked-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
Acked-by: Olivier Matz <olivier.matz@6wind.com>
Current APIs assume ring elements to be pointers. However, in many
use cases, the size can be different. Add new APIs to support
configurable ring element sizes.
Signed-off-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
Reviewed-by: Dharmik Thakkar <dharmik.thakkar@arm.com>
Reviewed-by: Gavin Hu <gavin.hu@arm.com>
Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
Acked-by: Olivier Matz <olivier.matz@6wind.com>
Merge all versions in linker version script files to DPDK_20.0.
This commit was generated by running the following command:
:~/DPDK$ buildtools/update-abi.sh 20.0
Signed-off-by: Pawel Modrak <pawelx.modrak@intel.com>
Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
Acked-by: Bruce Richardson <bruce.richardson@intel.com>
Acked-by: Thomas Monjalon <thomas@monjalon.net>
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>
Currently, the flush is done by dequeuing the ring in a while loop. It is
much simpler to flush the queue by resetting the head and tail indices.
Signed-off-by: Gavin Hu <gavin.hu@arm.com>
Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
Acked-by: Olivier Matz <olivier.matz@6wind.com>
Now that everything that has ever accessed the shared memory
config is doing so through the public API's, we can make it
internal. Since we're removing quite a few headers from
rte_eal_memconfig.h, we need to add them back in places
where this header is used.
This bumps the ABI, so also change all build files and make
update documentation.
Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
Acked-by: Stephen Hemminger <stephen@networkplumber.org>
Acked-by: David Marchand <david.marchand@redhat.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>
As memzone.h is introduced by
commit 38c9817ee1 ("mempool: adjust name size in related data types"),
forward declaration for rte_memzone is no longer needed.
Signed-off-by: Xiaolong Ye <xiaolong.ye@intel.com>
Acked-by: Olivier Matz <olivier.matz@6wind.com>
For files that already have rte_string_fns.h included in them, we can
do a straight replacement of snprintf(..."%s",...) with strlcpy. The
changes in this patch were auto-generated via command:
spatch --sp-file devtools/cocci/strlcpy-with-header.cocci --dir . --in-place
Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
'/**<' style comments apply to the previous member, which caused doxygen to
emit the RTE_RING_NAMESIZE documentation for RTE_RING_MZ_PREFIX.
Fixes: 38c9817ee1 ("mempool: adjust name size in related data types")
Cc: stable@dpdk.org
Signed-off-by: Gage Eads <gage.eads@intel.com>
Log message should end with newline.
Fixes: 4e32101f9b ("ring: support freeing")
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Reviewed-by: Rami Rosen <ramirose@gmail.com>
In weak memory models, like arm64, reading the prod.tail may get
reordered after reading the ring slots, which corrupts the ring and
stale data is observed.
This issue was reported by NXP on 8-A72 DPAA2 board. The problem is most
likely caused by missing the acquire semantics when reading
prod.tail (in SC dequeue) which makes it possible to read a
stale value from the ring slots.
For MP (and MC) case, rte_atomic32_cmpset() already provides the required
ordering. For SP case, the control depependency between if-statement (which
depends on the read of r->cons.tail) and the later stores to the ring slots
make RMB unnecessary. About the control dependency, read more at:
https://www.cl.cam.ac.uk/~pes20/ppc-supplemental/test7.pdf
This patch is adding the required read barrier to prevent reading the ring
slots get reordered before reading prod.tail for SC case.
Fixes: c9fb3c6289 ("ring: move code in a new header file")
Cc: stable@dpdk.org
Signed-off-by: Gavin Hu <gavin.hu@arm.com>
Reviewed-by: Ola Liljedahl <ola.liljedahl@arm.com>
Tested-by: Nipun Gupta <nipun.gupta@nxp.com>
Acked-by: Nipun Gupta <nipun.gupta@nxp.com>
Acked-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
When calling __atomic_compare_exchange_n, use relaxed ordering for the
success case, as multiple producers/consumers do not release updates to
each other so no need for acquire or release ordering.
Because the thread fence in place, ordering for the first iteration can
be relaxed.
Run the ring perf test on the following testbed:
HW: ThunderX2 B0 CPU CN9975 v2.0, 2 sockets, 28core,4 threads/core,2.5GHz
OS: Ubuntu 16.04.5 LTS, Kernel: 4.15.0-36-generic
DPDK: 18.08, Configuration: arm64-armv8a-linuxapp-gcc
gcc: 8.1.0
$sudo ./test/test/test -l 16-19,44-47,72-75,100-103 -n 4 \
--socket-mem=1024 -- -i
Without the patch:
*** Testing using two physical cores ***
SP/SC bulk enq/dequeue (size: 8): 5.75
MP/MC bulk enq/dequeue (size: 8): 10.18
SP/SC bulk enq/dequeue (size: 32): 1.80
MP/MC bulk enq/dequeue (size: 32): 2.34
With the patch:
*** Testing using two physical cores ***
SP/SC bulk enq/dequeue (size: 8): 5.59
MP/MC bulk enq/dequeue (size: 8): 10.54
SP/SC bulk enq/dequeue (size: 32): 1.73
MP/MC bulk enq/dequeue (size: 32): 2.38
No significant improvement, nor regression was seen, as the optimisation
is not at the critical path.
Fixes: 39368ebfc6 ("ring: introduce C11 memory model barrier option")
Cc: stable@dpdk.org
Signed-off-by: Gavin Hu <gavin.hu@arm.com>
Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
Reviewed-by: Steve Capper <steve.capper@arm.com>
Reviewed-by: Ola Liljedahl <ola.liljedahl@arm.com>
Use case scenario:
1) Thread 1 is enqueuing. It reads prod.head and gets stalled for some
reasons (running out of cpu time, preempted,...)
2) Thread 2 is enqueuing. It succeeds in enqueuing and moves prod.head
forward.
3) Thread 3 is dequeuing. It succeeds in dequeuing and moves the cons.tail
beyond the prod.head read by thread 1.
4) Thread 1 is re-scheduled. It reads cons.tail.
cpu1(producer) cpu2(producer) cpu3(consumer)
load r->prod.head
^ load r->prod.head
| load r->cons.tail
| store r->prod.head(+n)
stalled <-- enqueue ----->
| store r->prod.tail(+n)
| load r->cons.head
| load r->prod.tail
| store r->cons.head(+n)
| <...dequeue.....>
v store r->cons.tail(+n)
load r->cons.tail
For thread 1, the __atomic_compare_exchange_n detects the outdated
prod.head and retry the flow with the new one. This retry flow works ok on
strong ordering platform(eg:x86). But for weak ordering platforms(arm,
ppc), loading cons.tail and prod.head might be re-ordered, prod.head is new
but cons.tail becomes too old, the retry flow, based on the detection of
outdated head, does not trigger as expected, thus the outdate cons.tail
causes wrong free_entries.
Similarly, for dequeuing, outdated prod.tail leads to wrong avail_entries.
The fix is to keep the deterministic order of two loads allowing the retry
to work.
Run the ring perf test on the following testbed:
HW: ThunderX2 B0 CPU CN9975 v2.0, 2 sockets, 28core, 4 threads/core, 2.5GHz
OS: Ubuntu 16.04.5 LTS, Kernel: 4.15.0-36-generic
DPDK: 18.08, Configuration: arm64-armv8a-linuxapp-gcc
gcc: 8.1.0
$sudo ./test/test/test -l 16-19,44-47,72-75,100-103 -n 4 \
--socket-mem=1024 -- -i
Without the patch:
*** Testing using two physical cores ***
SP/SC bulk enq/dequeue (size: 8): 5.64
MP/MC bulk enq/dequeue (size: 8): 9.58
SP/SC bulk enq/dequeue (size: 32): 1.98
MP/MC bulk enq/dequeue (size: 32): 2.30
With the patch:
*** Testing using two physical cores ***
SP/SC bulk enq/dequeue (size: 8): 5.75
MP/MC bulk enq/dequeue (size: 8): 10.18
SP/SC bulk enq/dequeue (size: 32): 1.80
MP/MC bulk enq/dequeue (size: 32): 2.34
The results showed the thread fence degrade the performance slightly, but
it is required for correctness.
Fixes: 39368ebfc6 ("ring: introduce C11 memory model barrier option")
Cc: stable@dpdk.org
Signed-off-by: Gavin Hu <gavin.hu@arm.com>
Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
Reviewed-by: Steve Capper <steve.capper@arm.com>
Reviewed-by: Ola Liljedahl <ola.liljedahl@arm.com>
In __rte_ring_move_prod_head, move the __atomic_load_n up and out of
the do {} while loop as upon failure the old_head will be updated,
another load is costly and not necessary.
This helps a little on the latency,about 1~5%.
Test result with the patch(two cores):
SP/SC bulk enq/dequeue (size: 8): 5.64
MP/MC bulk enq/dequeue (size: 8): 9.58
SP/SC bulk enq/dequeue (size: 32): 1.98
MP/MC bulk enq/dequeue (size: 32): 2.30
Fixes: 39368ebfc6 ("ring: introduce C11 memory model barrier option")
Cc: stable@dpdk.org
Signed-off-by: Gavin Hu <gavin.hu@arm.com>
Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
Reviewed-by: Steve Capper <steve.capper@arm.com>
Reviewed-by: Ola Liljedahl <ola.liljedahl@arm.com>
Reviewed-by: Jia He <justin.he@arm.com>
Acked-by: Jerin Jacob <jerin.jacob@caviumnetworks.com>
Tested-by: Jerin Jacob <jerin.jacob@caviumnetworks.com>
Acked-by: Olivier Matz <olivier.matz@6wind.com>
Synchronize the load-acquire of the tail and the store-release
within update_tail, the store release ensures all the ring operations,
enqueue or dequeue, are seen by the observers on the other side as soon
as they see the updated tail. The load-acquire is needed here as the
data dependency is not a reliable way for ordering as the compiler might
break it by saving to temporary values to boost performance.
When computing the free_entries and avail_entries, use atomic semantics
to load the heads and tails instead.
The patch was benchmarked with test/ring_perf_autotest and it decreases
the enqueue/dequeue latency by 5% ~ 27.6% with two lcores, the real gains
are dependent on the number of lcores, depth of the ring, SPSC or MPMC.
For 1 lcore, it also improves a little, about 3 ~ 4%.
It is a big improvement, in case of MPMC, with two lcores and ring size
of 32, it saves latency up to (3.26-2.36)/3.26 = 27.6%.
This patch is a bug fix, while the improvement is a bonus. In our analysis
the improvement comes from the cacheline pre-filling after hoisting load-
acquire from _atomic_compare_exchange_n up above.
The test command:
$sudo ./test/test/test -l 16-19,44-47,72-75,100-103 -n 4 --socket-mem=\
1024 -- -i
Test result with this patch(two cores):
SP/SC bulk enq/dequeue (size: 8): 5.86
MP/MC bulk enq/dequeue (size: 8): 10.15
SP/SC bulk enq/dequeue (size: 32): 1.94
MP/MC bulk enq/dequeue (size: 32): 2.36
In comparison of the test result without this patch:
SP/SC bulk enq/dequeue (size: 8): 6.67
MP/MC bulk enq/dequeue (size: 8): 13.12
SP/SC bulk enq/dequeue (size: 32): 2.04
MP/MC bulk enq/dequeue (size: 32): 3.26
Fixes: 39368ebfc6 ("ring: introduce C11 memory model barrier option")
Cc: stable@dpdk.org
Signed-off-by: Gavin Hu <gavin.hu@arm.com>
Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
Reviewed-by: Steve Capper <steve.capper@arm.com>
Reviewed-by: Ola Liljedahl <ola.liljedahl@arm.com>
Reviewed-by: Jia He <justin.he@arm.com>
Acked-by: Jerin Jacob <jerin.jacob@caviumnetworks.com>
Tested-by: Jerin Jacob <jerin.jacob@caviumnetworks.com>
Acked-by: Olivier Matz <olivier.matz@6wind.com>
Keep only single config option RTE_USE_C11_MEM_MODEL for C11 memory
model, so all modules can leverage C11 atomic extension by enable this
option.
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: Jerin Jacob <jerin.jacob@caviumnetworks.com>
Reviewed-by: Ferruh Yigit <ferruh.yigit@intel.com>
Signed-off-by: Thomas Monjalon <thomas@monjalon.net>
rte_ring implementation is not preemptible only under certain
circumstances. This clarification is helpful for data plane and
control plane communication using rte_ring.
Signed-off-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
Reviewed-by: Gavin Hu <gavin.hu@arm.com>
Reviewed-by: Ola Liljedahl <ola.liljedahl@arm.com>
Acked-by: Olivier Matz <olivier.matz@6wind.com>
On gcc 5.4.0 / native aarch64 from Ubuntu 16.04:
In function '__rte_ring_do_dequeue':
rte_ring.h: 385:35: warning:
conversion to 'int' from 'unsigned int' may change
the sign of the result [-Wsign-conversion]
n = __rte_ring_move_cons_head(r, is_sc, n, behavior,
^
Fixes: e8ed5056c8 ("ring: remove signed type flip-flopping")
Cc: stable@dpdk.org
Signed-off-by: Andy Green <andy@warmcat.com>
Acked-by: Olivier Matz <olivier.matz@6wind.com>
GCC 8.1 warns:
rte_ring.h:350:46:
warning: conversion to 'uint32_t' {aka 'unsigned int'}
from 'int' may change the sign of the result
[-Wsign-conversion]
update_tail(&r->prod, prod_head, prod_next, is_sp, 1);
The visible apis take unsigned int, then call a private
api taking an int, which finally calls an api taking an
unsigned int.
Convert the private api to take unsigned int removing
5 x warning similar to that shown above.
Fixes: 0dfc98c507 ("ring: separate out head index manipulation")
Cc: stable@dpdk.org
Signed-off-by: Andy Green <andy@warmcat.com>
Acked-by: Olivier Matz <olivier.matz@6wind.com>
There were warnings with GCC 8.1:
In function '__rte_ring_move_prod_head':
rte_ring_generic.h:76:3:
warning: ISO C90 forbids mixed declarations and code
[-Wdeclaration-after-statement]
const uint32_t cons_tail = r->cons.tail;
^~~~~
In function '__rte_ring_move_cons_head':
rte_ring_generic.h:147:3:
warning: ISO C90 forbids mixed declarations and code
[-Wdeclaration-after-statement]
const uint32_t prod_tail = r->prod.tail;
Fixes: 0dfc98c507 ("ring: separate out head index manipulation")
Cc: stable@dpdk.org
Signed-off-by: Andy Green <andy@warmcat.com>
Acked-by: Olivier Matz <olivier.matz@6wind.com>
The initial objective of
commit d9f0d3a1ff ("ring: remove split cacheline build setting")
was to add an empty cache line between the producer and consumer
data (on platform with cache line size = 64B), preventing from
having them on adjacent cache lines.
Following discussion on the mailing list, it appears that this
also imposes an alignment constraint that is not required.
This patch removes the extra alignment constraint and adds the
empty cache lines using padding fields in the structure. The
size of rte_ring structure and the offset of the fields remain
the same on platforms with cache line size = 64B:
rte_ring = 384
rte_ring.name = 0
rte_ring.flags = 32
rte_ring.memzone = 40
rte_ring.size = 48
rte_ring.mask = 52
rte_ring.prod = 128
rte_ring.cons = 256
But it has an impact on platform where cache line size is 128B:
rte_ring = 384 -> 768
rte_ring.name = 0
rte_ring.flags = 32
rte_ring.memzone = 40
rte_ring.size = 48
rte_ring.mask = 52
rte_ring.prod = 128 -> 256
rte_ring.cons = 256 -> 512
Suggested-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
Signed-off-by: Olivier Matz <olivier.matz@6wind.com>
