Commit Graph

87 Commits

Author SHA1 Message Date
Stephen Hemminger
c0c055f5f7 ring: fix an error message
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>
2019-04-03 18:39:16 +02:00
Gavin Hu
85cffb2ecc ring: enforce reading tail before slots
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>
2019-03-28 01:22:04 +01:00
Gavin Hu
49594a6314 ring/c11: relax ordering for load and store of the head
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>
2018-11-13 17:00:58 +01:00
Gavin Hu
86757c2c3e ring/c11: keep deterministic order allowing retry to work
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>
2018-11-13 16:57:58 +01:00
Gavin Hu
047adc1724 ring/c11: move atomic load of head above the loop
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>
2018-11-05 14:34:27 +01:00
Gavin Hu
9ed8770628 ring/c11: synchronize load and store of the tail
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>
2018-11-05 14:34:19 +01:00
Phil Yang
ede56cc18d config: rename option for C11 memory model
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>
2018-10-26 18:09:22 +02:00
Ferruh Yigit
73aa5c1332 ring: add library version to meson build
Fixes: a3d6026711 ("ring: relax alignment constraint on ring structure")
Cc: stable@dpdk.org

Signed-off-by: Ferruh Yigit <ferruh.yigit@intel.com>
Acked-by: Luca Boccassi <bluca@debian.org>
2018-10-25 14:30:05 +02:00
Honnappa Nagarahalli
4a6e683c4c ring: clarify preemptible nature of algorithm
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>
2018-08-05 20:06:10 +02:00
Andy Green
ea771bc2a9 ring: fix sign conversion warning
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>
2018-07-26 16:11:51 +02:00
Andy Green
44c41b8577 ring: fix declaration after statement
On gcc 5.4.0 / native aarch64 from Ubuntu 16.04:

In function '__rte_ring_move_prod_head':
rte_ring_c11_mem.h:69:3: 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_c11_mem.h:136:3: warning:
ISO C90 forbids mixed declarations and code
[-Wdeclaration-after-statement]
   const uint32_t prod_tail = r->prod.tail;
   ^

Fixes: 39368ebfc6 ("ring: introduce C11 memory model barrier option")
Cc: stable@dpdk.org

Signed-off-by: Andy Green <andy@warmcat.com>
Acked-by: Olivier Matz <olivier.matz@6wind.com>
2018-07-26 16:11:51 +02:00
Andy Green
e8ed5056c8 ring: remove signed type flip-flopping
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>
2018-05-21 00:20:16 +02:00
Andy Green
712a3db0b5 ring: remove useless variables
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>
2018-05-21 00:20:12 +02:00
Olivier Matz
a3d6026711 ring: relax alignment constraint on ring structure
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>
2018-04-18 00:24:22 +02:00
Pavan Nikhilesh
3e8ea3d3d4 lib: remove unused map symbols
Signed-off-by: Pavan Nikhilesh <pbhagavatula@caviumnetworks.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Hemant Agrawal <hemant.agrawal@nxp.com>
Acked-by: Ferruh Yigit <ferruh.yigit@intel.com>
2018-02-13 14:55:01 +01:00
Jia He
9ffdaaa122 ring: convert license headers to SPDX tags
Signed-off-by: Jia He <jia.he@hxt-semitech.com>
Acked-by: Hemant Agrawal <hemant.agrawal@nxp.com>
2018-02-01 01:46:45 +01:00
Bruce Richardson
6c9457c279 build: replace license text with SPDX tag
Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
Reviewed-by: Luca Boccassi <bluca@debian.org>
2018-01-30 21:58:59 +01:00
Bruce Richardson
5b9656b157 lib: build with meson
Add non-EAL libraries to DPDK build. The compat lib is a special case,
along with the previously-added EAL, but all other libs can be build using
the same set of commands, where the individual meson.build files only need
to specify their dependencies, source files, header files and ABI versions.

Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
Reviewed-by: Harry van Haaren <harry.van.haaren@intel.com>
Acked-by: Keith Wiles <keith.wiles@intel.com>
Acked-by: Luca Boccassi <luca.boccassi@gmail.com>
2018-01-30 17:49:16 +01:00
Jia He
39368ebfc6 ring: introduce C11 memory model barrier option
This patch is to support C11 memory model barrier in librte_ring.

There are 2 barrier implementation options in librte_ring (suggested
by Jerin).
1. use rte_smp_rmb
2. use load_acquire/store_release(refer to [1]).
The reason why providing 2 options is the performance benchmark
difference in different arm machines, refer to [2].

CONFIG_RTE_RING_USE_C11_MEM_MODEL is provided, and by default it is "n"
on any architectures and only "y" on arm64 so far.

[1] https://github.com/freebsd/freebsd/blob/master/sys/sys/buf_ring.h#L170
[2] http://dpdk.org/ml/archives/dev/2017-October/080861.html

Suggested-by: Jerin Jacob <jerin.jacob@caviumnetworks.com>
Signed-off-by: Jia He <jia.he@hxt-semitech.com>
Acked-by: Jerin Jacob <jerin.jacob@caviumnetworks.com>
Acked-by: Olivier Matz <olivier.matz@6wind.com>
Acked-by: Jianbo Liu <jianbo.liu@arm.com>
Acked-by: Hemant Agrawal <hemant.agrawal@nxp.com>
2018-01-29 16:10:20 +01:00
Jia He
c9fb3c6289 ring: move code in a new header file
Move the common part of rte_ring.h into rte_ring_generic.h.
Move the memory barrier part into update_tail().

No functional changes here.

Suggested-by: Jerin Jacob <jerin.jacob@caviumnetworks.com>
Suggested-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
Signed-off-by: Jia He <jia.he@hxt-semitech.com>
Acked-by: Jerin Jacob <jerin.jacob@caviumnetworks.com>
Acked-by: Olivier Matz <olivier.matz@6wind.com>
Acked-by: Hemant Agrawal <hemant.agrawal@nxp.com>
2018-01-29 16:04:43 +01:00
Adrien Mazarguil
0d440d081c lib: fix missing includes in exported headers
Many exported headers rely on definitions found in rte_config.h without
including it, as shown by the following command:

 grep -L '^#include <rte_config.h>' -- \
  $(grep -Rl \
    $(sed -n '/^#define \([^ ]\+\).*$/{s//\1/;H;};${x;s/\n//;s/\n/\\|/g;p;}' \
      build/include/rte_config.h) \
    -- build/include/)

We cannot assume external applications will include rte_config.h on their
own, neither directly nor through a -include parameter like DPDK does
internally.

This not only causes obvious compilation failures that can be reproduced
with check-includes.sh such as:

 [...]/rte_memory.h:88:43: error: ‘RTE_CACHE_LINE_SIZE’ was not declared in
     this scope
  #define __rte_cache_aligned __rte_aligned(RTE_CACHE_LINE_SIZE)
                                            ^

It also results in less visible issues, for instance rte_hash_crc.h relying
on RTE_ARCH_X86_64's presence to provide dedicated inline functions.

This patch partially reverts the commit below and adds missing include
lines to the remaining files.

Fixes: f1a7a5c5f4 ("remove include of generated config header")
Cc: stable@dpdk.org

Signed-off-by: Adrien Mazarguil <adrien.mazarguil@6wind.com>
Acked-by: Thomas Monjalon <thomas@monjalon.net>
2018-01-17 00:31:05 +01:00
Bruce Richardson
369991d997 lib: use SPDX tag for Intel copyright files
Replace the BSD license header with the SPDX tag for files
with only an Intel copyright on them.

Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
2018-01-04 22:41:39 +01:00
Jia He
9bc2cbb007 ring: guarantee load/load order in enqueue and dequeue
We watched a rte panic of mbuf_autotest in our qualcomm arm64 server
(Amberwing).

Root cause:
In __rte_ring_move_cons_head()
...
        do {
                /* Restore n as it may change every loop */
                n = max;

                *old_head = r->cons.head;                //1st load
                const uint32_t prod_tail = r->prod.tail; //2nd load

In weak memory order architectures (powerpc,arm), the 2nd load might be
reodered before the 1st load, that makes *entries is bigger than we wanted.
This nasty reording messed enque/deque up.

cpu1(producer)          cpu2(consumer)          cpu3(consumer)
                        load r->prod.tail
in enqueue:
load r->cons.tail
load r->prod.head

store r->prod.tail

                                                load r->cons.head
                                                load r->prod.tail
                                                ...
                                                store r->cons.{head,tail}
                        load r->cons.head

Then, r->cons.head will be bigger than prod_tail, then make *entries very
big and the consumer will go forward incorrectly.

After this patch, the old cons.head will be recaculated after failure of
rte_atomic32_cmpset

There is no such issue on X86, because X86 is strong memory order model.
But rte_smp_rmb() doesn't have impact on runtime performance on X86, so
keep the same code without architectures specific concerns.

Fixes: 50d7690548 ("ring: add burst API")
Cc: stable@dpdk.org

Signed-off-by: Jia He <jia.he@hxt-semitech.com>
Signed-off-by: Jie Liu <jie2.liu@hxt-semitech.com>
Signed-off-by: Bing Zhao <bing.zhao@hxt-semitech.com>
Acked-by: Jerin Jacob <jerin.jacob@caviumnetworks.com>
Acked-by: Jianbo Liu <jianbo.liu@arm.com>
2017-11-12 18:59:14 +01:00
Olivier Matz
cbc12b0a96 mk: do not generate LDLIBS from directory dependencies
The list of libraries in LDLIBS was generated from the DEPDIRS-xyz
variable. This is valid when the subdirectory name match the library
name, but it's not always the case, especially for PMDs.

The patches removes this feature and explicitly adds the proper
libraries in LDLIBS.

Some DEPDIRS-xyz variables become useless, remove them.

Reported-by: Gage Eads <gage.eads@intel.com>
Signed-off-by: Olivier Matz <olivier.matz@6wind.com>
Reviewed-by: Gage Eads <gage.eads@intel.com>
2017-10-24 02:14:57 +02:00
Olivier Matz
72ca23c1ce ring: increase maximum ring size
There is no reason to prevent ring from being larger than 0x0FFFFFFF.
Increase the maximum size to 0x7FFFFFFF, which is the maximum possible
without changing the code and the structure definition (size is stored
on a uint32_t).

Link: http://dpdk.org/ml/archives/dev/2017-September/074701.html

Suggested-by: Venkatesh Nuthula <venki497@gmail.com>
Signed-off-by: Olivier Matz <olivier.matz@6wind.com>
Reviewed-by: Anatoly Burakov <anatoly.burakov@intel.com>
2017-10-05 23:23:12 +02:00
Bruce Richardson
b744611555 ring: allow non power-of-2 sizes
The rte_rings traditionally have only supported having ring sizes as powers
of 2, with the actual usable space being the size - 1. In some cases, for
example, with an eventdev where we want to precisely control queue depths
for latency, we need to allow ring sizes which are not powers of two so we
add in an additional ring capacity value to allow that. For existing rings,
this value will be size-1, i.e. the same as the mask, but if the new
EXACT_SZ flag is passed on ring creation, the ring will have exactly the
usable space requested, although the underlying memory size may be bigger.

Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
Acked-by: Olivier Matz <olivier.matz@6wind.com>
2017-07-07 09:29:17 +02:00
Jerin Jacob
577329e66b eal: switch to architecture specific pause function
Remove rte_pause() definition from rte_common.h and
switchover to architecture specific rte_pause.h

Signed-off-by: Jerin Jacob <jerin.jacob@caviumnetworks.com>
2017-07-03 23:58:51 +02:00
Daniel Verkamp
aae9817d5d ring: use aligned memzone allocation
rte_memzone_reserve() provides cache line alignment, but
struct rte_ring may require more than cache line alignment: on x86-64,
it needs 128-byte alignment due to PROD_ALIGN and CONS_ALIGN, which are
128 bytes, but cache line size is 64 bytes.

Fixes runtime warnings with UBSan enabled.

Fixes: d9f0d3a1ff ("ring: remove split cacheline build setting")
Cc: stable@dpdk.org

Signed-off-by: Daniel Verkamp <daniel.verkamp@intel.com>
2017-07-01 13:26:18 +02:00
Anand B Jyoti
077d248889 ring: fix return value for dequeue
The error return code for rte_ring_sc_dequeue_bulk() and
rte_ring_mc_dequeue_bulk() function should be -ENOENT rather
than -ENOBUFS as described in the function description.

Fixes: cfa7c9e6fc ("ring: make bulk and burst return values consistent")
Cc: stable@dpdk.org

Signed-off-by: Anand B Jyoti <anand.b.jyoti@intel.com>
Acked-by: Olivier Matz <olivier.matz@6wind.com>
2017-06-23 14:45:28 +02:00
Jerin Jacob
c0583d98a9 eal: introduce macro for always inline
Different drivers use internal macros like force_inline for compiler
always inline feature.
Standardizing it through __rte_always_inline macro.

Verified the change by comparing the output binary file.
No difference found in the output binary file with this change.

Signed-off-by: Jerin Jacob <jerin.jacob@caviumnetworks.com>
Acked-by: Bruce Richardson <bruce.richardson@intel.com>
2017-06-06 17:21:55 +02:00
Bruce Richardson
fc0ddc6848 ring: fix return value for single dequeue
The error return code for rte_ring_dequeue() function should be -ENOENT
rather than -ENOBUFS (which is the error value from the enqueue() fn).

Fixes: cfa7c9e6fc ("ring: make bulk and burst return values consistent")

Reported-by: Zhihong Wang <zhihong.wang@intel.com>
Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
2017-04-13 17:18:27 +02:00
Ed Czeck
65d9e621fa ring: fix C++ cast error
build error:
include/rte_ring.h:459:22: error: invalid conversion from ‘void*’
to ‘void**’ [-fpermissive]
  ENQUEUE_PTRS(r, &r[1], prod_head, obj_table, n, void *);

Implicit casts of void* to void** are considered warnings in some
compilers.  E.g. g++ version 5.8.  Cast directly to object types

Fixes: a6619414 ("ring: make struct and macros type agnostic")

Signed-off-by: Ed Czeck <ed.czeck@atomicrules.com>
Acked-by: Olivier Matz <olivier.matz@6wind.com>
2017-04-06 17:55:54 +02:00
Ferruh Yigit
3061d0d961 ring: fix build with icc
build error:
In file included from .../lib/librte_ring/rte_ring.c(90):
.../lib/librte_ring/rte_ring.h(162):
error #1366: a reduction in alignment without the "packed" attribute
is ignored
  } __rte_cache_aligned;
      ^

Alignment attribute moved to first element of the struct

Fixes: a6619414e0 ("ring: make struct and macros type agnostic")

Signed-off-by: Ferruh Yigit <ferruh.yigit@intel.com>
Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
2017-04-05 18:20:42 +02:00
Bruce Richardson
a6619414e0 ring: make struct and macros type agnostic
Modify the enqueue and dequeue macros to support copying any type of
object by passing in the exact object type. Rather than using the "ring"
structure member of rte_ring, which is of type "array of void *", instead
have the macros take the start of the ring a a pointer value, thereby
leaving the rte_ring structure as purely a header value. This allows it
to be reused by other future ring types which can add on extra fields if
they want, or even to have the actual ring elements, of whatever type
stored separate from the ring header.

Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
Reviewed-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Acked-by: Olivier Matz <olivier.matz@6wind.com>
2017-03-29 22:32:20 +02:00
Bruce Richardson
6a68df7f23 ring: create common function for updating tail index
Both producer and consumer use the same logic for updating the tail
index so merge into a single function.

Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
Reviewed-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Acked-by: Olivier Matz <olivier.matz@6wind.com>
2017-03-29 22:32:20 +02:00
Bruce Richardson
0dfc98c507 ring: separate out head index manipulation
We can write a single common function for head manipulation for enq
and a common one for deq, allowing us to have a single worker function
for enq and deq, rather than two of each. Update all other inline
functions to use the new functions.

Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
Reviewed-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Acked-by: Olivier Matz <olivier.matz@6wind.com>
2017-03-29 22:32:20 +02:00
Bruce Richardson
3fe963a85a ring: reduce scope of local variables
The local variable i is only used for loop control so define it in
the enqueue and dequeue blocks directly, rather than at the function
level.

Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
Reviewed-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Acked-by: Olivier Matz <olivier.matz@6wind.com>
2017-03-29 22:32:20 +02:00
Bruce Richardson
ecaed092b6 ring: return remaining entry count when dequeuing
Add an extra parameter to the ring dequeue burst/bulk functions so that
those functions can optionally return the amount of remaining objs in the
ring. This information can be used by applications in a number of ways,
for instance, with single-consumer queues, it provides a max
dequeue size which is guaranteed to work.

Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
Reviewed-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Acked-by: Olivier Matz <olivier.matz@6wind.com>
2017-03-29 22:32:20 +02:00
Bruce Richardson
14fbffb0aa ring: return free space when enqueuing
Add an extra parameter to the ring enqueue burst/bulk functions so that
those functions can optionally return the amount of free space in the
ring. This information can be used by applications in a number of ways,
for instance, with single-producer queues, it provides a max
enqueue size which is guaranteed to work. It can also be used to
implement watermark functionality in apps, replacing the older
functionality with a more flexible version, which enables apps to
implement multiple watermark thresholds, rather than just one.

Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
Reviewed-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Acked-by: Olivier Matz <olivier.matz@6wind.com>
2017-03-29 22:32:04 +02:00
Bruce Richardson
cfa7c9e6fc ring: make bulk and burst return values consistent
The bulk fns for rings returns 0 for all elements enqueued and negative
for no space. Change that to make them consistent with the burst functions
in returning the number of elements enqueued/dequeued, i.e. 0 or N.
This change also allows the return value from enq/deq to be used directly
without a branch for error checking.

Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
Reviewed-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Acked-by: Olivier Matz <olivier.matz@6wind.com>
2017-03-29 22:25:37 +02:00
Bruce Richardson
77dd306427 ring: remove watermark support
Remove the watermark support. A future commit will add support for having
enqueue functions return the amount of free space in the ring, which will
allow applications to implement their own watermark checks, while also
being more useful to the app.

Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
Reviewed-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Acked-by: Olivier Matz <olivier.matz@6wind.com>
2017-03-29 22:25:34 +02:00
Bruce Richardson
82cb88375c ring: remove the yield when waiting for tail update
There was a compile time setting to enable a ring to yield when
it entered a loop in mp or mc rings waiting for the tail pointer update.
Build time settings are not recommended for enabling/disabling features,
and since this was off by default, remove it completely. If needed, a
runtime enabled equivalent can be used.

Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
Reviewed-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Acked-by: Olivier Matz <olivier.matz@6wind.com>
2017-03-29 22:25:29 +02:00
Bruce Richardson
8c82198978 ring: remove debug setting
The debug option only provided statistics to the user, most of
which could be tracked by the application itself. Remove this as a
compile time option, and feature, simplifying the code.

Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
Reviewed-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Acked-by: Olivier Matz <olivier.matz@6wind.com>
2017-03-29 22:25:27 +02:00
Bruce Richardson
d1e138e1b0 ring: eliminate duplication of size and mask fields
The size and mask fields are duplicated in both the producer and
consumer data structures. Move them out of that into the top level
structure so they are not duplicated.

Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
Reviewed-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Acked-by: Olivier Matz <olivier.matz@6wind.com>
2017-03-29 22:25:23 +02:00
Bruce Richardson
8526571400 ring: create common structure for prod and cons metadata
create a common structure to hold the metadata for the producer and
the consumer, since both need essentially the same information - the
head and tail values, the ring size and mask.

Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
Reviewed-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Acked-by: Olivier Matz <olivier.matz@6wind.com>
2017-03-29 22:25:13 +02:00
Bruce Richardson
d9f0d3a1ff ring: remove split cacheline build setting
Users compiling DPDK should not need to know or care about the arrangement
of cachelines in the rte_ring structure.  Therefore just remove the build
option and set the structures to be always split. On platforms with 64B
cachelines, for improved performance use 128B rather than 64B alignment
since it stops the producer and consumer data being on adjacent cachelines.

Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
Reviewed-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Acked-by: Olivier Matz <olivier.matz@6wind.com>
2017-03-29 22:21:51 +02:00
Olivier Matz
feb9f680cd mk: optimize directory dependencies
Before this patch, the management of dependencies between directories
had several issues:

- the generation of .depdirs, done at configuration is slow: it can take
  more than one minute on some slow targets (usually ~10s on a standard
  PC without -j).

- for instance, it is possible to express a dependency like:
  - app/foo depends on lib/librte_foo
  - and lib/librte_foo depends on app/bar
  But this won't work because the directories are traversed with a
  depth-first algorithm, so we have to choose between doing 'app' before
  or after 'lib'.

- the script depdirs-rule.sh is too complex.

- we cannot use "make -d" for debug, because the output of make is used for
  the generation of .depdirs.

This patch moves the DEPDIRS-* variables in the upper Makefile, making
the dependencies much easier to calculate. A DEPDIRS variable is still
used to process library dependencies in LDLIBS.

After this commit, "make config" is almost immediate.

Signed-off-by: Olivier Matz <olivier.matz@6wind.com>
Tested-by: Robin Jarry <robin.jarry@6wind.com>
Tested-by: Jerin Jacob <jerin.jacob@caviumnetworks.com>
2017-03-27 23:28:43 +02:00
Bruce Richardson
03437f2947 ring: add a function to return the ring size
Applications and other libraries should not be reading inside the
rte_ring structure directly to get the ring size. Instead add a fn
to allow it to be queried.

Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
Acked-by: Olivier Matz <olivier.matz@6wind.com>
2017-03-08 16:05:19 +01:00
Yong Wang
247bde5231 doc: fix typos in code comments
Signed-off-by: Yong Wang <wang.yong19@zte.com.cn>
Acked-by: John McNamara <john.mcnamara@intel.com>
2016-12-06 15:25:01 +01:00
Mauricio Vasquez B
29f1cb4b38 doc: fix file argument of debug functions
Previous patch updated the functions without updating all the comments.

Fixes: 591a9d7985 ("add FILE argument to debug functions")

Signed-off-by: Mauricio Vasquez B <mauricio.vasquez@polito.it>
Acked-by: John McNamara <john.mcnamara@intel.com>
2016-10-13 21:25:53 +02:00