rte_timer_subsystem_init() may return -EALREADY if it has been already
initialized. Therefore put explicitly into doxygen that this is not a
failure for the application.
Signed-off-by: Stanislaw Kardach <kda@semihalf.com>
Reviewed-by: Michal Krawczyk <mk@semihalf.com>
Acked-by: Erik Gabriel Carrillo <erik.g.carrillo@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>
If a timer's callback function calls rte_timer_reset_sync() or
rte_timer_stop_sync() on another timer that is in the RUNNING state and
owned by the current lcore, the *_sync() calls will loop indefinitely.
Relatedly, if a timer's callback function calls *_sync() on another
timer that is in the RUNNING state and is owned by a different lcore,
but a timer callback function runs on that different lcore and calls
*_sync() on a timer that is in the RUNNING state and owned by the
current lcore, the two lcores will loop indefinitely.
Add a note in the rte_timer_stop_sync and rte_timer_reset_sync
documentation that indicates that these APIs should not be used inside
timer callback functions in order to avoid the hangs described above,
and suggests an alternative.
Bugzilla ID: 491
Cc: stable@dpdk.org
Signed-off-by: Erik Gabriel Carrillo <erik.g.carrillo@intel.com>
Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
Some new APIs were added to the timer library in the 19.05 release, and
there have been no changes to their interfaces since then. These
functions can be considered stable enough to remove their 'experimental'
tag.
Signed-off-by: Erik Gabriel Carrillo <erik.g.carrillo@intel.com>
Acked-by: Ray Kinsella <mdr@ashroe.eu>
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>
Volatile has no ordering semantics. The rte_timer structure defines
timer status as a volatile variable and uses the rte_r/wmb barrier
to guarantee inter-thread visibility.
This patch optimized the volatile operation with c11 atomic operations
and one-way barrier to save the performance penalty. According to the
timer_perf_autotest benchmarking results, this patch can uplift 10%~16%
timer appending performance, 3%~20% timer resetting performance and 45%
timer callbacks scheduling performance on aarch64 and no loss in
performance for x86.
Suggested-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
Signed-off-by: Phil Yang <phil.yang@arm.com>
Reviewed-by: Gavin Hu <gavin.hu@arm.com>
Acked-by: Erik Gabriel Carrillo <erik.g.carrillo@intel.com>
rte_timer_subsystem_initialized is a global variable that can be
accessed by multiple processes simultaneously. Hence, any access
to rte_timer_subsystem_initialized should be protected by
rte_mcfg_timer_lock.
Fixes: f9d6cd8bfe ("timer: fix resource leak in finalize")
Cc: stable@dpdk.org
Signed-off-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
Reviewed-by: Gavin Hu <gavin.hu@arm.com>
Reviewed-by: Phil Yang <phil.yang@arm.com>
Acked-by: Erik Gabriel Carrillo <erik.g.carrillo@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>
Timer, LPM and Distributor libraries no longer use function versioning
and therefore do not need separate build for static and shared version
of libraries.
This patch removes use_function_versioning from their meson build files
and corresponding include from the sources.
Fixes: f2fb215843 ("timer: remove deprecated code")
Fixes: 6e5b516761 ("distributor: remove deprecated code")
Fixes: c381a8d554 ("lpm: remove deprecated code")
Cc: stable@dpdk.org
Signed-off-by: Andrzej Ostruszka <aostruszka@marvell.com>
Acked-by: Bruce Richardson <bruce.richardson@intel.com>
Acked-by: David Marchand <david.marchand@redhat.com>
It is useful to know when the next timer will expire when
using rte_epoll_wait (or sleep when idle). This experimental
API provides a hook to query the number of ticks remaining.
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Acked-by: Erik Gabriel Carrillo <erik.g.carrillo@intel.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>
Remove code for old ABI versions ahead of ABI version bump.
Signed-off-by: Marcin Baran <marcinx.baran@intel.com>
Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
Acked-by: Bruce Richardson <bruce.richardson@intel.com>
Acked-by: Erik Gabriel Carrillo <erik.g.carrillo@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>
Every implementation of a particular version of given symbol needs to be
marked in its declaration as such (using `__vsym` macro). This patch
fixes this and also clarifies the documentation about that.
Signed-off-by: Andrzej Ostruszka <aostruszka@marvell.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Any file with ABI versioned functions needs different macros for shared and
static builds, so we need to accommodate that. Rather than building
everything twice, we just flag to the build system which libraries need
that handling, by setting use_function_versioning in the meson.build files.
To ensure we don't get silent errors at build time due to this meson flag
being missed, we add an explicit error to the function versioning header
file if a known C macro is not defined. Since "make" builds always only
build one of shared or static libraries, this define can be always set, and
so is added to the global CFLAGS. For meson, the build flag - and therefore
the C define - is set for the three libraries that need the function
versioning: "distributor", "lpm" and "timer".
Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
Acked-by: Stephen Hemminger <stephen@networkplumber.org>
Tested-by: Andrzej Ostruszka <amo@semihalf.com>
Reviewed-by: Andrzej Ostruszka <amo@semihalf.com>
The compat.h header file provided macros for two purposes:
1. it provided the macros for marking functions as rte_experimental
2. it provided the macros for doing function versioning
Although these were in the same file, #1 is something that is for use by
public header files, which #2 is for internal use only. Therefore, we can
split these into two headers, keeping #1 in rte_compat.h and #2 in a new
file rte_function_versioning.h. For "make" builds, since internal objects
pick up the headers from the "include/" folder, we need to add the new
header to the installation list, but for "meson" builds it does not need to
be installed as it's not for public use.
The rework also serves to allow the use of the function versioning macros
to files that actually need them, so the use of experimental functions does
not need including of the versioning code.
Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
Acked-by: Stephen Hemminger <stephen@networkplumber.org>
Reviewed-by: Andrzej Ostruszka <amo@semihalf.com>
If the timer subsystem is not initialized before rte_timer_manage (for
example) is invoked, a pointer to a shared hugepage memory region will
still be null and dereferenced when it is checked for validity; handle
this case.
Fixes: c0749f7096 ("timer: allow management in shared memory")
Cc: stable@dpdk.org
Signed-off-by: Erik Gabriel Carrillo <erik.g.carrillo@intel.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: c0749f7096 ("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>
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>
Now that some of the symbols in the timer lib are versioned, the
Doxygen documentation that is generated is incorrect. Group all
versioned symbols, listing the generic name first, and remove comments
for older versions of symbols.
Fixes: c0749f7096 ("timer: allow management in shared memory")
Signed-off-by: Erik Gabriel Carrillo <erik.g.carrillo@intel.com>
Since memzones can be reserved from secondary processes as well as
primary processes, if the first call to the timer subsystem init
function occurs in a secondary process, we should allow it to succeed.
Fixes: c0749f7096 ("timer: allow management in shared memory")
Signed-off-by: Erik Gabriel Carrillo <erik.g.carrillo@intel.com>
The rte_timer_alt_manage function should track which is the running
timer and whether or not it was updated by a callback in the priv_timer
structure that corresponds to the running lcore, so that restarting
or stopping the timer from the callback works correctly.
Fixes: c0749f7096 ("timer: allow management in shared memory")
Signed-off-by: Erik Gabriel Carrillo <erik.g.carrillo@intel.com>
A null array is allowed to be passed as one of the parameters to
rte_timer_alt_manage() as a convenience. When that happened, an
anonymous array was created using compound literal syntax, and Coverity
detected that the object was out of scope in later uses of it. Create
an object in the proper scope instead.
Coverity issue: 337919
Fixes: c0749f7096 ("timer: allow management in shared memory")
Signed-off-by: Erik Gabriel Carrillo <erik.g.carrillo@intel.com>
This commit adds an autotest which exercises new timer reset/stop APIs
in a secondary process. Timers are created, and sometimes stopped, in
the secondary process, and their expiration is checked for and handled
in the primary process.
Signed-off-by: Erik Gabriel Carrillo <erik.g.carrillo@intel.com>
Add a function to the timer API that allows a caller to traverse a
specified set of timer lists, stopping each timer in each list,
and invoking a callback function.
Signed-off-by: Erik Gabriel Carrillo <erik.g.carrillo@intel.com>
Currently, the timer library uses a per-process table of structures to
manage skiplists of timers presumably because timers contain arbitrary
function pointers whose value may not resolve properly in other
processes.
However, if the same callback is used handle all timers, and that
callback is only invoked in one process, then it woud be safe to allow
the data structures to be allocated in shared memory, and to allow
secondary processes to modify the timer lists. This would let timers be
used in more multi-process scenarios.
The library's global variables are wrapped with a struct, and an array
of these structures is created in shared memory. The original APIs
are updated to reference the zeroth entry in the array. This maintains
the original behavior for both primary and secondary processes since
the set intersection of their coremasks should be empty [1]. New APIs
are introduced to enable the allocation/deallocation of other entries
in the array.
New variants of the APIs used to start and stop timers are introduced;
they allow a caller to specify which array entry should be used to
locate the timer list to insert into or delete from.
Finally, a new variant of rte_timer_manage() is introduced, which
allows a caller to specify which array entry should be used to locate
the timer lists to process; it can also process multiple timer lists per
invocation.
[1] https://doc.dpdk.org/guides/prog_guide/multi_proc_support.html#multi-process-limitations
Signed-off-by: Erik Gabriel Carrillo <erik.g.carrillo@intel.com>
rte_timer_manage() adds expired timers to a "run list", and walks the
list, transitioning each timer from the PENDING to the RUNNING state.
If another lcore resets or stops the timer at precisely this
moment, the timer state would instead be set to CONFIG by that other
lcore, which would cause timer_manage() to skip over it. This is
expected behavior.
However, if a timer expires quickly enough, there exists the
following race condition that causes the timer_manage() routine to
misinterpret a timer in CONFIG state, resulting in lost timers:
- Thread A:
- starts a timer with rte_timer_reset()
- the timer is moved to CONFIG state
- the spinlock associated with the appropriate skiplist is acquired
- timer is inserted into the skiplist
- the spinlock is released
- Thread B:
- executes rte_timer_manage()
- find above timer as expired, add it to run list
- walk run list, see above timer still in CONFIG state, unlink it from
run list and continue on
- Thread A:
- move timer to PENDING state
- return from rte_timer_reset()
- timer is now in PENDING state, but not actually linked into a
pending list or a run list and will never get processed further
by rte_timer_manage()
This commit fixes this race condition by only releasing the spinlock
after the timer state has been transitioned from CONFIG to PENDING,
which prevents rte_timer_manage() from seeing an incorrect state.
Fixes: 9b15ba895b ("timer: use a skip list")
Cc: stable@dpdk.org
Signed-off-by: Erik Gabriel Carrillo <erik.g.carrillo@intel.com>
Reviewed-by: Gavin Hu <gavin.hu@arm.com>
rte_lcore_has_role() returns 0 if role of lcore matches requested
role. The return value of the API is confusing, and this is a known
problem with a deprecation notice announcing the change to more
intuitive semantics:
Commit 064518f68d ("doc: announce EAL API change to lcore role function")
Implement changes announced in the deprecation notice, and remove it.
Also, fix usages of this API to reflect the change. Control thread patches
expected new behavior and were broken before, now they are fixed as well.
Fixes: d651ee4919 ("eal: set affinity for control threads")
Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
Signed-off-by: Erik Gabriel Carrillo <erik.g.carrillo@intel.com>
Signed-off-by: Thomas Monjalon <thomas@monjalon.net>
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>
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>
The return value of rte_lcore_has_role is misinterpreted in the timer
reset function. The return values of rte_lcore_has_role will be changed
in a future DPDK release, but this commit fixes this call site until
that happens.
Fixes: 351f463456 ("timer: allow reset on service cores")
Cc: stable@dpdk.org
Signed-off-by: Erik Gabriel Carrillo <erik.g.carrillo@intel.com>
Acked-by: Pavan Nikhilesh <pbhagavatula@caviumnetworks.com>
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>
The memzone header is often included without good reason.
Signed-off-by: Thomas Monjalon <thomas@monjalon.net>
Acked-by: Bruce Richardson <bruce.richardson@intel.com>
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>
64bit load and store will be an atomic operation on all the
64bit processors.
Change RTE_ARCH_X86_64 to RTE_ARCH_64 to reflect the case.
Fixes: 9b15ba895b ("timer: use a skip list")
Cc: stable@dpdk.org
Signed-off-by: Jerin Jacob <jerin.jacob@caviumnetworks.com>
The rte_timer_reset function should be able to register timers on service
lcores as they are EAL threads.
Signed-off-by: Pavan Nikhilesh <pbhagavatula@caviumnetworks.com>
Acked-by: Harry van Haaren <harry.van.haaren@intel.com>
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>
Fixing typos across dpdk source code using codespell utility.
Skipped the ethdev driver's base code fixes to keep the base
code intact.
Signed-off-by: Jerin Jacob <jerin.jacob@caviumnetworks.com>
Acked-by: John McNamara <john.mcnamara@intel.com>
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>
For periodic timers, if the lag gets introduced, the current code
added additional delay when the next peridoc timer was initialized
by not taking into account the delay added, with this fix the code
would start the next occurrence of timer keeping in account the
lag added. Corrected the behavior.
Fixes: 9b15ba89 ("timer: use a skip list")
Signed-off-by: Karmarkar Suyash <skarmarkar@sonusnet.com>
Acked-by: Robert Sanford <rsanford@akamai.com>
Exported header files used by applications should allow the strictest
compiler flags. Language extensions used in many places must be explicitly
marked to avoid warnings and compilation failures.
Unnamed structs/unions are allowed since C11, however many compiler
versions do not use this mode by default.
This commit prevents the following errors:
error: ISO C99 doesn't support unnamed structs/unions
error: struct has no named members
Signed-off-by: Adrien Mazarguil <adrien.mazarguil@6wind.com>
When timer_cb resets another running timer on the same lcore,
the list of expired timers is chained to the pending-list.
This commit prevents a running timer from being reset
by not its own timer_cb.
Fixes: a4b7a5a45c ("timer: fix race condition")
Signed-off-by: Hiroyuki Mikita <h.mikita89@gmail.com>
Acked-by: Robert Sanford <rsanford@akamai.com>
When timer_set_running_state() fails in rte_timer_manage(),
the failed timer is put back on pending-list.
In this case, another core tries to reset or stop the timer.
It does not need to be on pending-list.
Fixes: a4b7a5a45c ("timer: fix race condition")
Signed-off-by: Hiroyuki Mikita <h.mikita89@gmail.com>
Acked-by: Robert Sanford <rsanford@akamai.com>
This commit fixes incorrect pending-list manipulation
when getting list of expired timers in rte_timer_manage().
When timer_get_prev_entries() sets pending_head on prev,
the pending-list is broken.
The next of pending_head always becomes NULL.
In this depth level, it is not need to manipulate the list.
Fixes: 9b15ba895b ("timer: use a skip list")
Signed-off-by: Hiroyuki Mikita <h.mikita89@gmail.com>
Acked-by: Robert Sanford <rsanford@akamai.com>
Eliminate problematic race condition in rte_timer_manage() that can
lead to corruption of per-lcore pending-lists (implemented as
skip-lists). The race condition occurs when rte_timer_manage() expires
multiple timers on lcore A, while lcore B simultaneously invokes
rte_timer_reset() for one of the expiring timers (other than the first
one).
Lcore A splits its pending-list, creating a local list of expired timers
linked through their sl_next[0] pointers, and sets the first expired
timer to the RUNNING state, all during one list-lock round trip.
Lcore A then unlocks the list-lock to run the first callback, and that
is when A and B can have different interpretations of the subsequent
expired timers' true state. Lcore B sees an expired timer still in the
PENDING state, atomically changes the timer to the CONFIG state, locks
lcore A's list-lock, and reinserts the timer into A's pending-list.
The two lcores try to use the same next-pointers to maintain both lists!
Our solution is to remove expired timers from the pending-list and try
to set them all to the RUNNING state in one atomic step, i.e.,
rte_timer_manage() should perform these two actions within one
ownership of the list-lock.
After splitting the pending-list at the current point in time and trying
to set all expired timers to the RUNNING state, we must put back into
the pending-list any timers that we failed to set to the RUNNING state,
all while still holding the list-lock. It is then safe to release the
lock and run the callback functions for all expired timers that remain
on our local run-list.
Signed-off-by: Robert Sanford <rsanford@akamai.com>
