[v16,0/9] eal: Add EAL API for threading
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Return-Path: <dev-bounces@dpdk.org> X-Original-To: patchwork@inbox.dpdk.org Delivered-To: patchwork@inbox.dpdk.org Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id AE800A0C41; Sat, 9 Oct 2021 09:42:08 +0200 (CEST) Received: from [217.70.189.124] (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 3219D40142; Sat, 9 Oct 2021 09:42:08 +0200 (CEST) Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by mails.dpdk.org (Postfix) with ESMTP id 7497440040 for <dev@dpdk.org>; Sat, 9 Oct 2021 09:42:06 +0200 (CEST) Received: by linux.microsoft.com (Postfix, from userid 1059) id BE9BE20B8008; Sat, 9 Oct 2021 00:42:05 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com BE9BE20B8008 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1633765325; bh=gFPSCDkrXEI+X4O3fIwny7Zc9FVumPpowKOLinzJRXs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=N6PZbdqo53TGqycvgIi3W3tqB2v/mGqoBxLZ55oXrMxvk292fpyzj5xFSIui0sCgF mQfKvTPIrYo2NMt7unT6CVGmdfwGKJ1ohGQVHbN1N2fYZXZxvuM2tWD9owbv33ppdy KVuuWauRGxIxL7UxU/HyIsvnUBlyAcShCtlyPQKo= From: Narcisa Ana Maria Vasile <navasile@linux.microsoft.com> To: dev@dpdk.org, thomas@monjalon.net, dmitry.kozliuk@gmail.com, khot@microsoft.com, navasile@microsoft.com, dmitrym@microsoft.com, roretzla@microsoft.com, talshn@nvidia.com, ocardona@microsoft.com Cc: bruce.richardson@intel.com, david.marchand@redhat.com, pallavi.kadam@intel.com Date: Sat, 9 Oct 2021 00:41:49 -0700 Message-Id: <1633765318-28356-1-git-send-email-navasile@linux.microsoft.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1633732841-17873-1-git-send-email-navasile@linux.microsoft.com> References: <1633732841-17873-1-git-send-email-navasile@linux.microsoft.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Subject: [dpdk-dev] [PATCH v16 0/9] eal: Add EAL API for threading X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK patches and discussions <dev.dpdk.org> List-Unsubscribe: <https://mails.dpdk.org/options/dev>, <mailto:dev-request@dpdk.org?subject=unsubscribe> List-Archive: <http://mails.dpdk.org/archives/dev/> List-Post: <mailto:dev@dpdk.org> List-Help: <mailto:dev-request@dpdk.org?subject=help> List-Subscribe: <https://mails.dpdk.org/listinfo/dev>, <mailto:dev-request@dpdk.org?subject=subscribe> Errors-To: dev-bounces@dpdk.org Sender: "dev" <dev-bounces@dpdk.org> |
Message
Narcisa Ana Maria Vasile
Oct. 9, 2021, 7:41 a.m. UTC
From: Narcisa Vasile <navasile@microsoft.com>
EAL thread API
**Problem Statement**
DPDK currently uses the pthread interface to create and manage threads.
Windows does not support the POSIX thread programming model,
so it currently
relies on a header file that hides the Windows calls under
pthread matched interfaces. Given that EAL should isolate the environment
specifics from the applications and libraries and mediate
all the communication with the operating systems, a new EAL interface
is needed for thread management.
**Goals**
* Introduce a generic EAL API for threading support that will remove
the current Windows pthread.h shim.
* Replace references to pthread_* across the DPDK codebase with the new
RTE_THREAD_* API.
* Allow users to choose between using the RTE_THREAD_* API or a
3rd party thread library through a configuration option.
**Design plan**
New API main files:
* rte_thread.h (librte_eal/include)
* rte_thread.c (librte_eal/windows)
* rte_thread.c (librte_eal/common)
**A schematic example of the design**
--------------------------------------------------
lib/librte_eal/include/rte_thread.h
int rte_thread_create();
lib/librte_eal/common/rte_thread.c
int rte_thread_create()
{
return pthread_create();
}
lib/librte_eal/windows/rte_thread.c
int rte_thread_create()
{
return CreateThread();
}
-----------------------------------------------------
**Thread attributes**
When or after a thread is created, specific characteristics of the thread
can be adjusted. Given that the thread characteristics that are of interest
for DPDK applications are affinity and priority, the following structure
that represents thread attributes has been defined:
typedef struct
{
enum rte_thread_priority priority;
rte_cpuset_t cpuset;
} rte_thread_attr_t;
The *rte_thread_create()* function can optionally receive
an rte_thread_attr_t
object that will cause the thread to be created with the
affinity and priority
described by the attributes object. If no rte_thread_attr_t is passed
(parameter is NULL), the default affinity and priority are used.
An rte_thread_attr_t object can also be set to the default values
by calling *rte_thread_attr_init()*.
*Priority* is represented through an enum that currently advertises
two values for priority:
- RTE_THREAD_PRIORITY_NORMAL
- RTE_THREAD_PRIORITY_REALTIME_CRITICAL
The enum can be extended to allow for multiple priority levels.
rte_thread_set_priority - sets the priority of a thread
rte_thread_get_priority - retrieves the priority of a thread
from the OS
rte_thread_attr_set_priority - updates an rte_thread_attr_t object
with a new value for priority
The user can choose thread priority through an EAL parameter,
when starting an application. If EAL parameter is not used,
the per-platform default value for thread priority is used.
Otherwise administrator has an option to set one of available options:
--thread-prio normal
--thread-prio realtime
Example:
./dpdk-l2fwd -l 0-3 -n 4 –thread-prio normal -- -q 8 -p ffff
*Affinity* is described by the already known “rte_cpuset_t” type.
rte_thread_attr_set/get_affinity - sets/gets the affinity field in a
rte_thread_attr_t object
rte_thread_set/get_affinity – sets/gets the affinity of a thread
**Errors**
A translation function that maps Windows error codes to errno-style
error codes is provided.
**Future work**
The long term plan is for EAL to provide full threading support:
* Add support for conditional variables
* Additional functionality offered by pthread_*
(such as pthread_setname_np, etc.)
v16:
- Fix warning on freebsd by adding cast
- Change affinity unit test to consider ases when the requested CPU
are not available on the system.
- Fix priority unit test to avoid termination of thread before the
priority is checked.
v15:
- Add try_lock mutex functionality. If the mutex is already owned by a
different thread, the function returns immediately. Otherwise,
the mutex will be acquired.
- Add function for getting the priority of a thread.
An auxiliary function that translates the OS priority to the
EAL accepted ones is added.
- Fix unit tests logging, add descriptive asserts that mark test failures.
Verify mutex locking, verify barrier return values. Add test for
statically initialized mutexes.
- Fix Alpine build by removing the use of pthread_attr_set_affinity() and
using pthread_set_affinity() after the thread is created.
v14:
- Remove patch "eal: add EAL argument for setting thread priority"
This will be added later when enabling the new threading API.
- Remove priority enum value "_UNDEFINED". NORMAL is used
as the default.
- Fix issue with thread return value.
v13:
- Fix syntax error in unit tests
v12:
- Fix freebsd warning about initializer in unit tests
v11:
- Add unit tests for thread API
- Rebase
v10:
- Remove patch no. 10. It will be broken down in subpatches
and sent as a different patchset that depends on this one.
This is done due to the ABI breaks that would be caused by patch 10.
- Replace unix/rte_thread.c with common/rte_thread.c
- Remove initializations that may prevent compiler from issuing useful
warnings.
- Remove rte_thread_types.h and rte_windows_thread_types.h
- Remove unneeded priority macros (EAL_THREAD_PRIORITY*)
- Remove functions that retrieves thread handle from process handle
- Remove rte_thread_cancel() until same behavior is obtained on
all platforms.
- Fix rte_thread_detach() function description,
return value and remove empty line.
- Reimplement mutex functions. Add compatible representation for mutex
identifier. Add macro to replace static mutex initialization instances.
- Fix commit messages (lines too long, remove unicode symbols)
v9:
- Sign patches
v8:
- Rebase
- Add rte_thread_detach() API
- Set default priority, when user did not specify a value
v7:
Based on DmitryK's review:
- Change thread id representation
- Change mutex id representation
- Implement static mutex inititalizer for Windows
- Change barrier identifier representation
- Improve commit messages
- Add missing doxygen comments
- Split error translation function
- Improve name for affinity function
- Remove cpuset_size parameter
- Fix eal_create_cpu_map function
- Map EAL priority values to OS specific values
- Add thread wrapper for start routine
- Do not export rte_thread_cancel() on Windows
- Cleanup, fix comments, fix typos.
v6:
- improve error-translation function
- call the error translation function in rte_thread_value_get()
v5:
- update cover letter with more details on the priority argument
v4:
- fix function description
- rebase
v3:
- rebase
v2:
- revert changes that break ABI
- break up changes into smaller patches
- fix coding style issues
- fix issues with errors
- fix parameter type in examples/kni.c
Narcisa Vasile (9):
eal: add basic threading functions
eal: add thread attributes
eal/windows: translate Windows errors to errno-style errors
eal: implement functions for thread affinity management
eal: implement thread priority management functions
eal: add thread lifetime management
eal: implement functions for mutex management
eal: implement functions for thread barrier management
Add unit tests for thread API
app/test/meson.build | 2 +
app/test/test_threads.c | 372 ++++++++++++++++++
lib/eal/common/meson.build | 1 +
lib/eal/common/rte_thread.c | 497 ++++++++++++++++++++++++
lib/eal/include/rte_thread.h | 435 ++++++++++++++++++++-
lib/eal/unix/meson.build | 1 -
lib/eal/unix/rte_thread.c | 92 -----
lib/eal/version.map | 22 ++
lib/eal/windows/eal_lcore.c | 176 ++++++---
lib/eal/windows/eal_windows.h | 10 +
lib/eal/windows/include/sched.h | 2 +-
lib/eal/windows/rte_thread.c | 656 ++++++++++++++++++++++++++++++--
12 files changed, 2093 insertions(+), 173 deletions(-)
create mode 100644 app/test/test_threads.c
create mode 100644 lib/eal/common/rte_thread.c
delete mode 100644 lib/eal/unix/rte_thread.c