DPDK patches and discussions
 help / color / mirror / Atom feed
From: Suanming Mou <suanmingm@nvidia.com>
To: Dmitry Kozlyuk <dmitry.kozliuk@gmail.com>
Cc: Narcisa Ana Maria Vasile <navasile@linux.microsoft.com>,
	Dmitry Malloy <dmitrym@microsoft.com>,
	Pallavi Kadam <pallavi.kadam@intel.com>,
	"dev@dpdk.org" <dev@dpdk.org>
Subject: Re: [dpdk-dev] [PATCH 1/2] eal/windows: add pthread mutex lock
Date: Mon, 28 Sep 2020 02:30:37 +0000
Message-ID: <MN2PR12MB3550C8B9B2099DBCB36A66EFC1350@MN2PR12MB3550.namprd12.prod.outlook.com> (raw)
In-Reply-To: <20200927185657.6bbfdc1b@sovereign>

Hi Dmitry,

> -----Original Message-----
> From: Dmitry Kozlyuk <dmitry.kozliuk@gmail.com>
> Sent: Sunday, September 27, 2020 11:57 PM
> To: Suanming Mou <suanmingm@nvidia.com>
> Cc: Narcisa Ana Maria Vasile <navasile@linux.microsoft.com>; Dmitry Malloy
> <dmitrym@microsoft.com>; Pallavi Kadam <pallavi.kadam@intel.com>;
> dev@dpdk.org
> Subject: Re: [PATCH 1/2] eal/windows: add pthread mutex lock
> 
> Hi Suanming,
> 
> There's a remark in patch 2/2 and cover letter:
> 
> > If no lock contention
> > with the added rte flow level mutex, the mutex only does the atomic
> > increasing in pthread_mutex_lock() and decreasing in
> > pthread_mutex_unlock(). No futex() syscall will be involved.
> 
> Is this property important? To get the described behavior on Windows, you
> should've used CRITICAL_SECTION (preferably wrapped in a struct). Mutexes are
> kernel objects on Windows and always require syscalls. Otherwise, if mutexes
> are sufficient, see a comment inline.

The description was valid only for the standard posix pthread functions. Good to know that there are similar functions on Windows.
I will prefer to change it to CRICTIAL_SECTION functions, in this case the pthread wrap functions on Windows will also have less impact with the current applications.
Thank you very much for the information.

> 
> > Add pthread mutex lock as it is needed for the thread safe rte flow
> > functions.
> >
> > Signed-off-by: Suanming Mou <suanmingm@nvidia.com>
> > ---
> >  lib/librte_eal/windows/include/pthread.h | 46
> > ++++++++++++++++++++++++++++++++
> >  1 file changed, 46 insertions(+)
> >
> > diff --git a/lib/librte_eal/windows/include/pthread.h
> > b/lib/librte_eal/windows/include/pthread.h
> > index 99013dc..4e2e0b3 100644
> > --- a/lib/librte_eal/windows/include/pthread.h
> > +++ b/lib/librte_eal/windows/include/pthread.h
> > @@ -28,6 +28,10 @@
> >  /* defining pthread_attr_t type on Windows since there is no in
> > Microsoft libc*/  typedef void *pthread_attr_t;
> >
> > +typedef void *pthread_mutexattr_t;
> > +
> > +typedef HANDLE pthread_mutex_t;
> > +
> >  typedef SYNCHRONIZATION_BARRIER pthread_barrier_t;
> >
> >  #define pthread_barrier_init(barrier, attr, count) \ @@ -139,6
> > +143,48 @@
> >  	return 0;
> >  }
> >
> > +static inline int
> > +pthread_mutex_init(pthread_mutex_t *mutex,
> > +		   __rte_unused pthread_mutexattr_t *attr) {
> > +	*mutex = CreateMutex(NULL, FALSE, NULL);
> > +	if (*mutex == NULL) {
> > +		RTE_LOG_WIN32_ERR("CreateMutex()");
> > +		return -1;
> > +	}
> > +	return 0;
> > +}
> > +
> > +static inline int
> > +pthread_mutex_lock(pthread_mutex_t *mutex) {
> > +	if (WaitForSingleObject(*mutex, INFINITE) != WAIT_OBJECT_0) {
> > +		RTE_LOG_WIN32_ERR("WaitForSingleObject()");
> > +		return -1;
> 
> A relevant error code must be returned according to POSIX. Searching the code
> for pthread_mutex_lock() calls, I can see that hinic PMD checks for
> EOWNERDEAD (corresponding to WAIT_OBJECT_ABANDONED in Windows) and
> failsafe PMD supplies return value of pthread_mutex_unlock() to strerror(), i.e. it
> should be an errno. Same applies to other functions.

These PMDs should not be valid on Windows now, or the build will be failed as no pthread_mutex on Windows.
I guess we will have a much general solution with the posix APIs support on Windows?
Now the wrap functions solution is much like a WA to fix the build.

> 
> > +	}
> > +	return 0;
> > +}
> > +
> > +static inline int
> > +pthread_mutex_unlock(pthread_mutex_t *mutex) {
> > +	if (!ReleaseMutex(*mutex)) {
> > +		RTE_LOG_WIN32_ERR("ReleaseMutex()");
> > +		return -1;
> > +	}
> > +	return 0;
> > +}
> > +
> > +static inline int
> > +pthread_mutex_destroy(pthread_mutex_t *mutex) {
> > +	if (!CloseHandle(*mutex)) {
> > +		RTE_LOG_WIN32_ERR("CloseHandle()");
> > +		return -1;
> > +	}
> > +	return 0;
> > +}
> > +
> >  #ifdef __cplusplus
> >  }
> >  #endif


  reply	other threads:[~2020-09-28  2:31 UTC|newest]

Thread overview: 40+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-27  8:20 [dpdk-dev] [PATCH 0/2] ethdev: make rte flow API thread safe Suanming Mou
2020-09-27  8:20 ` [dpdk-dev] [PATCH 1/2] eal/windows: add pthread mutex lock Suanming Mou
2020-09-27 15:56   ` Dmitry Kozlyuk
2020-09-28  2:30     ` Suanming Mou [this message]
2020-09-27  8:20 ` [dpdk-dev] [PATCH 2/2] ethdev: make rte flow API thread safe Suanming Mou
2020-09-30 10:56   ` Ori Kam
2020-10-04 23:44     ` Suanming Mou
2020-10-04 23:48 ` [dpdk-dev] [PATCH v2 0/2] ethdev: make rte_flow " Suanming Mou
2020-10-04 23:48   ` [dpdk-dev] [PATCH v2 1/2] eal/windows: add pthread mutex lock Suanming Mou
2020-10-04 23:48   ` [dpdk-dev] [PATCH v2 2/2] ethdev: make rte_flow API thread safe Suanming Mou
2020-10-05 11:28     ` Ori Kam
2020-10-06 23:18       ` Ajit Khaparde
2020-10-07  0:50         ` Suanming Mou
2020-10-07  6:33           ` Ori Kam
2020-10-07 14:17 ` [dpdk-dev] [PATCH v3 0/2] " Suanming Mou
2020-10-07 14:17   ` [dpdk-dev] [PATCH v3 1/2] eal/windows: add pthread mutex lock Suanming Mou
2020-10-07 16:53     ` Dmitry Kozlyuk
2020-10-08  2:46       ` Suanming Mou
2020-10-14 10:02         ` Tal Shnaiderman
2020-10-07 14:17   ` [dpdk-dev] [PATCH v3 2/2] ethdev: make rte_flow API thread safe Suanming Mou
2020-10-07 14:42     ` Ajit Khaparde
2020-10-07 16:37       ` Ori Kam
2020-10-07 20:10     ` Matan Azrad
2020-10-08  2:56       ` Suanming Mou
2020-10-09  1:17 ` [dpdk-dev] [PATCH v4 0/2] " Suanming Mou
2020-10-09  1:17   ` [dpdk-dev] [PATCH v4 1/2] eal/windows: add pthread mutex lock Suanming Mou
2020-10-09  9:19     ` Tal Shnaiderman
2020-10-14 16:45     ` Ranjit Menon
2020-10-15  2:15     ` Narcisa Ana Maria Vasile
2020-10-15  2:18       ` Suanming Mou
2020-10-09  1:17   ` [dpdk-dev] [PATCH v4 2/2] ethdev: make rte_flow API thread safe Suanming Mou
2020-10-14 10:19     ` Thomas Monjalon
2020-10-14 10:41       ` Suanming Mou
2020-10-15  1:07 ` [dpdk-dev] [PATCH v5 0/2] " Suanming Mou
2020-10-15  1:07   ` [dpdk-dev] [PATCH v5 1/2] eal/windows: add pthread mutex lock Suanming Mou
2020-10-15  2:22     ` Narcisa Ana Maria Vasile
2020-10-15  1:07   ` [dpdk-dev] [PATCH v5 2/2] ethdev: make rte_flow API thread safe Suanming Mou
2020-10-15  8:28     ` Thomas Monjalon
2020-10-15  8:52       ` Andrew Rybchenko
2020-10-15 22:43   ` [dpdk-dev] [PATCH v5 0/2] " Thomas Monjalon

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=MN2PR12MB3550C8B9B2099DBCB36A66EFC1350@MN2PR12MB3550.namprd12.prod.outlook.com \
    --to=suanmingm@nvidia.com \
    --cc=dev@dpdk.org \
    --cc=dmitry.kozliuk@gmail.com \
    --cc=dmitrym@microsoft.com \
    --cc=navasile@linux.microsoft.com \
    --cc=pallavi.kadam@intel.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

DPDK patches and discussions

This inbox may be cloned and mirrored by anyone:

	git clone --mirror https://inbox.dpdk.org/dev/0 dev/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 dev dev/ https://inbox.dpdk.org/dev \
		dev@dpdk.org
	public-inbox-index dev

Example config snippet for mirrors.
Newsgroup available over NNTP:
	nntp://inbox.dpdk.org/inbox.dpdk.dev


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git