This patch adds the implementation of the 128-bit atomic compare
exchange API on aarch64. Using 64-bit 'ldxp/stxp' instructions
can perform this operation. Moreover, on the LSE atomic extension
accelerated platforms, it is implemented by 'casp' instructions for
better performance.
Since the '__ARM_FEATURE_ATOMICS' flag only supports GCC-9, this
patch adds a new config flag 'RTE_ARM_FEATURE_ATOMICS' to enable
the 'cas' version on older version compilers.
For octeontx2, we make sure that the lse (and other) extensions are
enabled even if the compiler does not know of the octeontx2 target
cpu.
Since direct x0 register used in the code and cas_op_name() and
rte_atomic128_cmp_exchange() is inline function, based on parent
function load, it may corrupt x0 register aka break aarch64 ABI.
Define CAS operations as rte_noinline functions to avoid an ABI
break [1].
1: https://git.dpdk.org/dpdk/commit/?id=5b40ec6b9662
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>
Reviewed-by: David Marchand <david.marchand@redhat.com>
This ensures secondary processes never have to calculate the TSC rate
themselves, which can be noticeable in VMs that don't have access to
arch-specific detection mechanism (such as CPUID leaf 0x15 or MSR 0xCE
on x86).
Since rte_mem_config is now internal to the EAL library, we can add
tsc_hz without ABI breakage concerns.
Reduces rte_eal_init() execution time in a secondary process from 165ms
to 66ms on my test system.
Signed-off-by: Jim Harris <james.r.harris@intel.com>
Acked-by: Bruce Richardson <bruce.richardson@intel.com>
For a valid service, the core mask of the service
is checked against the current core and the corresponding
entry in the active_on_lcore array is set or reset.
Upto 8 cores share the same cache line for their
service active_on_lcore array entries since each entry is a uint8_t.
Some number of these entries also share the cache line with
the internal_flags member of struct rte_service_spec_impl,
hence this false sharing also makes the service_valid() check
expensive.
Eliminate false sharing by moving the active_on_lcore array to
a per-core data structure. The array is now indexed by service id.
Signed-off-by: Nikhil Rao <nikhil.rao@intel.com>
Acked-by: Gage Eads <gage.eads@intel.com>
Acked-by: Harry van Haaren <harry.van.haaren@intel.com>
The rte_atomic64_exchange operation for ppc_64 incorrectly linked
back to a 32 bit generic operation (__atomic_exchange_4) rather than
the 64 bit generic operation (__atomic_exchange_8). As a result,
applications that used rte_eth_link_get_nowait() would only receive
the link speed, they would not receive the link state, link duplex,
or link autoneg properties.
Fixes: ff2863570fcc ("eal: introduce atomic exchange operation")
Cc: stable@dpdk.org
Signed-off-by: David Christensen <drc@linux.vnet.ibm.com>
Reviewed-by: David Marchand <david.marchand@redhat.com>
EAL should always use rte_log instead of putting errors to
stderr (which maybe redirected to /dev/null in a daemon).
Also checks for null before rte_free are unnecessary.
Minor code consistency improvements.
Fixes: 21698354c832 ("service: introduce service cores concept")
Cc: stable@dpdk.org
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Harry van Haaren <harry.van.haaren@intel.com>
Acked-by: Harry van Haaren <harry.van.haaren@intel.com>
Restrict this header inclusion to its real users.
Fixes: 028669bc9f0d ("eal: hide shared memory config")
Cc: stable@dpdk.org
Signed-off-by: David Marchand <david.marchand@redhat.com>
Acked-by: Anatoly Burakov <anatoly.burakov@intel.com>
ARM is supporting maximum 4 hugepage sizes (64K, 2M, 32M
and 1G) when granule is 4KB since very long and DPDK
support maximum 3 hugepage sizes.
With all 4 hugepage sizes enabled, applications and some
stacks like VPP which are working over DPDK and using
"in-memory" eal option, or using separate mount points
on ARM based platform, fails at huge page initialization,
reporting error messages from eal:
EAL: FATAL: Cannot get hugepage information.
EAL: Cannot get hugepage information.
EAL: Error - exiting with code: 1
This issue is originated from Linux 5.0
(a21b0b78eaf7 "arm64: hugetlb: Register hugepages during arch init")
where kernel is by default creating directories for each supported
hugepage size in /sys/kernel/mm/hugepages/
On earlier Stable Kernel LTR's, the directories visible in
/sys/kernel/mm/hugepages/ were dependent upon what hugepage
sizes are configured at boot time.
This change increases the maximum supported hugepage sizes
to 4 for ARM based platforms.
Cc: stable@dpdk.org
Signed-off-by: Gagandeep Singh <g.singh@nxp.com>
Signed-off-by: Nipun Gupta <nipun.gupta@nxp.com>
This function has never been used outside of this code unit.
Mark it static and remove it from the eal internal header.
Fixes: 9e29251b2afa ("eal: thread affinity API")
Cc: stable@dpdk.org
Signed-off-by: David Marchand <david.marchand@redhat.com>
When using --no-huge mode, dynamic allocation is not supported.
Because of this limitation, the option --legacy-mem is implied
and -m may be needed to specify the amount of memory to allocate.
Otherwise the default amount MEMSIZE_IF_NO_HUGE_PAGE will be allocated.
The option --socket-mem can also be used with --legacy-mem
when hugepages are supported.
Signed-off-by: Thomas Monjalon <thomas@monjalon.net>
Acked-by: Anatoly Burakov <anatoly.burakov@intel.com>
The ctrl thread cpu affinity setting has been broken when using --lcores.
Using -l/-c options makes each lcore associated to a physical cpu in a 1:1
fashion.
On the contrary, when using --lcores, each lcore cpu affinity can be set
to a list of any online cpu on the system.
To handle both cases, each lcore cpu affinity is considered and removed
from the process startup cpu affinity.
Introduced macros to manipulate dpdk cpu sets in both Linux and FreeBSD.
Examples on a 8 cores Linux system:
$ cd /sys/fs/cgroup/cpuset/
$ mkdir dpdk
$ cd dpdk
$ echo 4-7 > cpuset.cpus
$ echo 0 > cpuset.mems
$ echo $$ > tasks
Before the fix:
$ ./master/app/testpmd --master-lcore 0 --lcores '(0,7)@(7,4,5)' \
--no-huge --no-pci -m 512 -- -i --total-num-mbufs=2048
8427 cpu_list=4-5,7 testpmd
8428 cpu_list=4-6 eal-intr-thread
8429 cpu_list=4-6 rte_mp_handle
8430 cpu_list=4-5,7 lcore-slave-7
$ taskset -c 7 \
./master/app/testpmd --master-lcore 0 --lcores '(0,7)@(7,4,5)' \
--no-huge --no-pci -m 512 -- -i --total-num-mbufs=2048
EAL: Detected 8 lcore(s)
EAL: Detected 1 NUMA nodes
EAL: Failed to create thread for interrupt handling
EAL: FATAL: Cannot init interrupt-handling thread
EAL: Cannot init interrupt-handling thread
PANIC in main():
Cannot init EAL
After the fix:
$ ./master/app/testpmd --master-lcore 0 --lcores '(0,7)@(7,4,5)' \
--no-huge --no-pci -m 512 -- -i --total-num-mbufs=2048
15214 cpu_list=4-5,7 testpmd
15215 cpu_list=6 eal-intr-thread
15216 cpu_list=6 rte_mp_handle
15217 cpu_list=4-5,7 lcore-slave-7
$ taskset -c 7 \
./master/app/testpmd --master-lcore 0 --lcores '(0,7)@(7,4,5)' \
--no-huge --no-pci -m 512 -- -i --total-num-mbufs=2048
15297 cpu_list=4-5,7 testpmd
15298 cpu_list=4-5,7 eal-intr-thread
15299 cpu_list=4-5,7 rte_mp_handle
15300 cpu_list=4-5,7 lcore-slave-7
Bugzilla ID: 322
Fixes: c3568ea37670 ("eal: restrict control threads to startup CPU affinity")
Cc: stable@dpdk.org
Reported-by: Johan Källström <johan.kallstrom@ericsson.com>
Signed-off-by: David Marchand <david.marchand@redhat.com>
This was missed when promoting this API to stable.
Fixes: 7a0ac7cdb454 ("service: promote experimental functions to stable")
Signed-off-by: David Marchand <david.marchand@redhat.com>
Acked-by: Gage Eads <gage.eads@intel.com>
This reverts commit debacba0297fbe214b4185a9791e6a9fdf6642ba.
Reverting this patch as it currently breaks the initialization of
telemetry, more investigation is ongoing to fix the issue for the
printed error message for unrecognized argument.
Fixes: debacba0297f ("eal: fix parsing option --telemetry")
Cc: stable@dpdk.org
Signed-off-by: Sean Morrissey <sean.morrissey@intel.com>
Add new ack interrupt API to avoid using
VFIO_IRQ_SET_ACTION_TRIGGER(rte_intr_enable()) for
acking interrupt purpose for VFIO based interrupt handlers.
This implementation is specific to Linux.
Using rte_intr_enable() for acking interrupt has below issues
* Time consuming to do for every interrupt received as it will
free_irq() followed by request_irq() and all other initializations
* A race condition because of a window between free_irq() and
request_irq() with packet reception still on and device still
enabled and would throw warning messages like below.
[158764.159833] do_IRQ: 9.34 No irq handler for vector
In this patch, rte_intr_ack() is a no-op for VFIO_MSIX/VFIO_MSI interrupts
as they are edge triggered and kernel would not mask the interrupt before
delivering the event to userspace and we don't need to ack.
Signed-off-by: Nithin Dabilpuram <ndabilpuram@marvell.com>
Signed-off-by: Jerin Jacob <jerinj@marvell.com>
Tested-by: Shahed Shaikh <shshaikh@marvell.com>
Signed-off-by: David Marchand <david.marchand@redhat.com>
Added telemetry to EAL long options so that when
--telemetry is passed as an EAL arg that there is
no unrecognized argument error message printed.
Fixes: 8877ac688b52 ("telemetry: introduce infrastructure")
Cc: stable@dpdk.org
Signed-off-by: Sean Morrissey <sean.morrissey@intel.com>
Tested-by: John OLoughlin <john.oloughlin@intel.com>
Acked-by: Kevin Laatz <kevin.laatz@intel.com>
The incriminated commit broke the use of RTE_PCI_DRV_IOVA_AS_VA which
was intended to mean "driver only supports VA" but had been understood
as "driver supports both PA and VA" by most net drivers and used to let
dpdk processes to run as non root (which do not have access to physical
addresses on recent kernels).
The check on physical addresses actually closed the gap for those
drivers. We don't need to mark them with RTE_PCI_DRV_IOVA_AS_VA and this
flag can retain its intended meaning.
Document explicitly its meaning.
We can check that a driver requirement wrt to IOVA mode is fulfilled
before trying to probe a device.
Finally, document the heuristic used to select the IOVA mode and hope
that we won't break it again.
Fixes: 703458e19c16 ("bus/pci: consider only usable devices for IOVA mode")
Signed-off-by: David Marchand <david.marchand@redhat.com>
Reviewed-by: Jerin Jacob <jerinj@marvell.com>
Tested-by: Jerin Jacob <jerinj@marvell.com>
Acked-by: Anatoly Burakov <anatoly.burakov@intel.com>
This reverts commit 0cb86518db57d35e0abc14d6703fad561a0310e2.
The PCI bus now reports DC when faced with a device bound to an unknown
driver and, in such a case, the IOVA mode is selected against physical
address availability.
As a consequence, there is no reason for this special case for Mellanox
drivers.
Fixes: 703458e19c16 ("bus/pci: consider only usable devices for IOVA mode")
Signed-off-by: David Marchand <david.marchand@redhat.com>
Reviewed-by: Jerin Jacob <jerinj@marvell.com>
The old comment, on top of the function rte_eal_has_hugepages(),
is really outdated and not generic enough.
Signed-off-by: Thomas Monjalon <thomas@monjalon.net>
Acked-by: Anatoly Burakov <anatoly.burakov@intel.com>
Currently, when fbarray is destroyed, the fbarray structure is not
zeroed out, which leads to stale data being there and confusing
secondary process init in legacy mem mode. Fix it by always
memsetting the fbarray to zero when destroying it.
Fixes: 5b61c62cfd76 ("fbarray: add internal tailq for mapped areas")
Cc: stable@dpdk.org
Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
The functions rte_service_may_be_active(), rte_service_lcore_attr_get(),
and rte_service_attr_reset_all() were introduced nearly a year ago in DPDK
18.08. They can be considered non-experimental for the 19.08 release.
rte_service_may_be_active() is used by the sw PMD, and this commit allows
it to not need any experimental API.
Signed-off-by: Gage Eads <gage.eads@intel.com>
If there are multiple threads contending, they all attempt to take the
spinlock lock at the same time once it is released. This results in a
huge amount of processor bus traffic, which is a huge performance
killer. Thus, if we somehow order the lock-takers so that they know who
is next in line for the resource we can vastly reduce the amount of bus
traffic.
This patch added MCS lock library. It provides scalability by spinning
on a CPU/thread local variable which avoids expensive cache bouncings.
It provides fairness by maintaining a list of acquirers and passing the
lock to each CPU/thread in the order they acquired the lock.
Signed-off-by: Phil Yang <phil.yang@arm.com>
Reviewed-by: Steve Capper <steve.capper@arm.com>
Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
Reviewed-by: Gavin Hu <gavin.hu@arm.com>
Currently, whenever timer library is initialized, the memory
is leaked because there is no telling when primary or secondary
processes get to use the state, and there is no way to
initialize/deinitialize timer library state without race
conditions [1] because the data itself must live in shared memory.
Add a spinlock to the shared mem config to have a way to
exclusively initialize/deinitialize the timer library without
any races, and implement the synchronization mechanism based
on this lock in the timer library.
Also, update the API doc. Note that the behavior of the API
itself did not change - the requirement to call init in every
process was simply not documented explicitly.
[1] See the following email thread:
https://mails.dpdk.org/archives/dev/2019-May/131498.html
Fixes: c0749f7096c7 ("timer: allow management in shared memory")
Cc: stable@dpdk.org
Signed-off-by: Erik Gabriel Carrillo <erik.g.carrillo@intel.com>
Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
Acked-by: Erik Gabriel Carrillo <erik.g.carrillo@intel.com>
Reviewed-by: David Marchand <david.marchand@redhat.com>
Currently, nothing stops DPDK to attempt to run primary and
secondary processes while having different versions. This
can lead to all sorts of weird behavior and makes it harder
to maintain compatibility without breaking ABI every once
in a while.
Fix it by explicitly disallowing running different DPDK
versions as primary and secondary processes.
Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
Acked-by: David Marchand <david.marchand@redhat.com>
Currently, each EAL will update internal/shared config in their
own way at init, resulting in needless duplication of code and
OS-dependent behavior. Move the functions to a common file and
add missing FreeBSD steps.
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, mcfg completion function exists in two independent
implementations doing the same thing, which is bug prone.
Unify the two functions and move them into one place.
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, the function to wait until config completion is
static inline for no reason. Move its implementation to
an EAL common file.
Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
Acked-by: Stephen Hemminger <stephen@networkplumber.org>
Acked-by: David Marchand <david.marchand@redhat.com>
There is no reason to pack the memconfig structure, and doing so
gives out warnings in some static analyzers. Fix it by removing
the packed attributed.
Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
Acked-by: Stephen Hemminger <stephen@networkplumber.org>
Acked-by: David Marchand <david.marchand@redhat.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, in order to lock access to the mempool list, a direct
access to the shared memory structure is needed. 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>
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>
Currently, the memory hotplug is locked automatically by all
memory-related _walk() functions, but sometimes locking the
memory subsystem outside of them is needed. There is no
public API to do that, so it creates a dependency on shared
memory config to be public. Fix this by introducing a new
API to lock/unlock the memory hotplug subsystem.
Create a new common file for all things mem config, and a
new API namespace rte_mcfg_*, and search-and-replace all
usages of the locks with the new API.
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, if the bus selects IOVA as PA, the memory init can fail when
lacking access to physical addresses.
This can be quite hard for normal users to understand what is wrong
since this is the default behavior.
Catch this situation earlier in eal init by validating physical addresses
availability, or select IOVA when no clear preferrence had been expressed.
The bus code is changed so that it reports when it does not care about
the IOVA mode and let the eal init decide.
In Linux implementation, rework rte_eal_using_phys_addrs() so that it can
be called earlier but still avoid a circular dependency with
rte_mem_virt2phys().
In FreeBSD implementation, rte_eal_using_phys_addrs() always returns
false, so the detection part is left as is.
If librte_kni is compiled in and the KNI kmod is loaded,
- if the buses requested VA, force to PA if physical addresses are
available as it was done before,
- else, keep iova as VA, KNI init will fail later.
Signed-off-by: Ben Walker <benjamin.walker@intel.com>
Signed-off-by: David Marchand <david.marchand@redhat.com>
Acked-by: Anatoly Burakov <anatoly.burakov@intel.com>
The function rte_malloc_set_limit was defined but never implemented.
Mark it as deprecated for now, and remove in next release.
There is no point in keeping dead code.
"You Aren't Going to Need It"
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Acked-by: Anatoly Burakov <anatoly.burakov@intel.com>
According to API, 'rte_dev_probe()' and 'rte_dev_remove()' must
return 0 or negative error code. Bus code returns positive values
if device wasn't recognized by any driver, so the result of
'bus->plug/unplug()' must be converted. 'local_dev_probe()' and
'local_dev_remove()' also has their internal API, so the conversion
should be done there.
Positive on remove means that device not found by driver.
Positive on probe means that there are no suitable buses/drivers,
i.e. device is not supported.
Users of these API fixed to provide a good example by respecting
DPDK API. This also will allow to catch such issues in the future.
Fixes: a3ee360f4440 ("eal: add hotplug add/remove device")
Fixes: 244d5130719c ("eal: enable hotplug on multi-process")
Cc: stable@dpdk.org
Signed-off-by: Ilya Maximets <i.maximets@samsung.com>
Reviewed-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}' \
$(git grep -l __rte_experimental -- '*.h')
Special mention for rte_mbuf_data_addr_default():
There is either a bug or a (not yet understood) issue with gcc.
gcc won't drop this inline when unused and rte_mbuf_data_addr_default()
calls rte_mbuf_buf_addr() which itself is experimental.
This results in a build warning when not accepting experimental apis
from sources just including rte_mbuf.h.
For this specific case, we hide the call to rte_mbuf_buf_addr() under
the ALLOW_EXPERIMENTAL_API flag.
Signed-off-by: Adrien Mazarguil <adrien.mazarguil@6wind.com>
Signed-off-by: David Marchand <david.marchand@redhat.com>
We had some inconsistencies between functions prototypes and actual
definitions.
Let's avoid this by only adding the experimental tag to the prototypes.
Tests with gcc and clang show it is enough.
git grep -l __rte_experimental |grep \.c$ |while read file; do
sed -i -e '/^__rte_experimental$/d' $file;
sed -i -e 's/ *__rte_experimental//' $file;
sed -i -e 's/__rte_experimental *//' $file;
done
Signed-off-by: David Marchand <david.marchand@redhat.com>
Acked-by: Adrien Mazarguil <adrien.mazarguil@6wind.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
This function is not visible from outside this code unit.
Fixes: 84e7477e10b1 ("mem: add thread unsafe version for DMA mask check")
Cc: stable@dpdk.org
Signed-off-by: David Marchand <david.marchand@redhat.com>
Acked-by: Adrien Mazarguil <adrien.mazarguil@6wind.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
The incriminated commit promoted those symbols as stable but the
prototypes still have the tag.
Fixes: 73eca2f77f4c ("devargs: promote experimental API as stable")
Cc: stable@dpdk.org
Signed-off-by: David Marchand <david.marchand@redhat.com>
Acked-by: Adrien Mazarguil <adrien.mazarguil@6wind.com>
Acked-by: Stephen Hemminger <stephen@networkplumber.org>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
This API was experimental and not properly marked in the map file.
But looking more closely, this is just an internal wrapper for EAL init.
Hide it in the hotplug code.
Fixes: 244d5130719c ("eal: enable hotplug on multi-process")
Cc: stable@dpdk.org
Signed-off-by: David Marchand <david.marchand@redhat.com>
Acked-by: Adrien Mazarguil <adrien.mazarguil@6wind.com>
Acked-by: Stephen Hemminger <stephen@networkplumber.org>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
When seeding the pseudo-random number generator, replace the 64-bit
RDSEED with two 32-bit RDSEED instructions to allow building and
running on 32-bit x86.
Fixes: faf8fd252785 ("eal: improve entropy for initial PRNG seed")
Reported-by: Ferruh Yigit <ferruh.yigit@intel.com>
Signed-off-by: Mattias Rönnblom <mattias.ronnblom@ericsson.com>
Add a function rte_rand_max() which generates an uniformly distributed
pseudo-random number less than a user-specified upper bound.
The commonly used pattern rte_rand() % SOME_VALUE creates biased
results (as in some values in the range are more frequently occurring
than others) if SOME_VALUE is not a power of 2.
Signed-off-by: Mattias Rönnblom <mattias.ronnblom@ericsson.com>
Acked-by: Bruce Richardson <bruce.richardson@intel.com>
Replace the use of rte_get_timer_cycles() with getentropy() for
seeding the pseudo-random number generator. getentropy() provides a
more truly random value.
getentropy() requires glibc 2.25 and Linux kernel 3.17. In case
getentropy() is not found at compile time, or the relevant syscall
fails in runtime, the rdseed machine instruction will be used as a
fallback.
rdseed is only available on x86 (Broadwell or later). In case it is
not present, rte_get_timer_cycles() will be used as a second fallback.
On non-Meson builds, getentropy() will not be used.
Suggested-by: Bruce Richardson <bruce.richardson@intel.com>
Suggested-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Mattias Rönnblom <mattias.ronnblom@ericsson.com>
Acked-by: Bruce Richardson <bruce.richardson@intel.com>
This commit replaces rte_rand()'s use of lrand48() with a DPDK-native
combined Linear Feedback Shift Register (LFSR) (also known as
Tausworthe) pseudo-random number generator.
This generator is faster and produces better-quality random numbers
than the linear congruential generator (LCG) of lib's lrand48(). The
implementation, as opposed to lrand48(), is multi-thread safe in
regards to concurrent rte_rand() calls from different lcore threads.
A LCG is still used, but only to seed the five per-lcore LFSR
sequences.
In addition, this patch also addresses the issue of the legacy
implementation only producing 62 bits of pseudo randomness, while the
API requires all 64 bits to be random.
This pseudo-random number generator is not cryptographically secure -
just like lrand48().
Bugzilla ID: 114
Bugzilla ID: 276
Signed-off-by: Mattias Rönnblom <mattias.ronnblom@ericsson.com>
Acked-by: Bruce Richardson <bruce.richardson@intel.com>
Some helpers in the header file are forced inlined other are
only inlined, this patch forces inline for all.
It will avoid it to be embedded as functions when called multiple
times in the same object file. For example, when we added packed
ring support in vhost-user library, rte_memcpy_generic got no
more inlined.
Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Acked-by: Bruce Richardson <bruce.richardson@intel.com>
Currently, IPC API will silently ignore unsupported IPC.
Fix the API call to explicitly handle unsupported IPC cases.
Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
