From: Thomas Monjalon <thomas.monjalon@6wind.com>
To: jozmarti@cisco.com
Cc: dev@dpdk.org
Subject: Re: [dpdk-dev] [PATCH] rte_delay_us can be replaced with user function
Date: Thu, 22 Sep 2016 17:08:42 +0200 [thread overview]
Message-ID: <4326235.prI1QteV26@xps13> (raw)
In-Reply-To: <3d62cdb3b19648d8a4ed7e0ff4847db5@XCH-RCD-019.cisco.com>
2016-09-22 08:37, Jozef Martiniak -X:
> Hello Thomas,
>
> > First a general comment: please check your patch with scripts/checkpatches.sh.
> Done. checkpath.pl is taken from latest linux kernel...
I can see these warnings:
UNSPECIFIED_INT: Prefer 'unsigned int' to bare use of 'unsigned'
LEADING_SPACE: please, no spaces at the start of a line
> > What will happen if we need to provide more builtin handlers?
> > I still think that rte_delay_us_block can be exported and initialized
> The idea was to make this function simple&&fast as possible. If user needs
> more builtin handlers - he can implement this functionality within his delay
> function.
>
> Btw there is also another patch with the same functionality (uses weak symbols)
> which I would prefer:
> https://git.fd.io/cgit/vpp/tree/dpdk/dpdk-16.04_patches/0005-Allow-applications-to-override-rte_delay_us.patch
I don't like the VPP patch because it is hacky and weak symbols should
be avoided for static linking.
> Do you have any idea how should rte_delay_us_callback_register look like for
> multiple handlers ?
Yes, just as simple as an assignment:
void rte_delay_us_callback_register(void (*func)(unsigned))
{
rte_delay_us = func;
}
We just need to export rte_delay_us_block and call
rte_delay_us_callback_register(rte_delay_us_block)
at EAL initialization or in a constructor.
> Other comments are accepted.
>
> Best regards,
> Jozef
>
> -----Original Message-----
> From: Thomas Monjalon [mailto:thomas.monjalon@6wind.com]
> Sent: Wednesday, September 21, 2016 3:13 PM
> To: Jozef Martiniak -X (jozmarti - PANTHEON TECHNOLOGIES at Cisco) <jozmarti@cisco.com>
> Cc: dev@dpdk.org
> Subject: Re: [dpdk-dev] [PATCH] rte_delay_us can be replaced with user function
>
> Hi,
>
> I think this feature should enter in the release 16.11.
> We just need to make sure it is implemented with the right API.
> Do you have any comment about managing several builtin handlers?
>
>
> 2016-09-13 22:04, Thomas Monjalon:
> > Hi,
> >
> > Sorry for late review.
> > This patch was in a summer hole :/
> >
> > First a general comment: please check your patch with
> > scripts/checkpatches.sh.
> > In order to ease tracking of this patch, please increment the version
> > when sending a new one in the same thread:
> > git send-email -1 -v3 --annotate --to dev@dpdk.org \
> > --in-reply-to 1469016644-6521-1-git-send-email-jozmarti@cisco.com
> >
> > More comments below.
> >
> > 2016-07-20 14:10, jozmarti@cisco.com:
> > > +void rte_delay_us_callback_register(void (*userfunc)(unsigned)) {
> > > + if (userfunc == NULL)
> > > + rte_delay_us = rte_delay_us_block;
> >
> > Here you are creating an exception for rte_delay_us_block which is
> > mapped as a NULL handler.
> > What will happen if we need to provide more builtin handlers?
> > I still think that rte_delay_us_block can be exported and initialized
> > as the default handler. Other opinions are obviously welcome.
> >
> > > + else
> > > + rte_delay_us = userfunc;
> > > +}
> > > +
> > > +static void __attribute__((constructor))
> > > +rte_timer_init(void)
> > > +{
> > > + /* set rte_delay_us_block as a delay function */
> > > + rte_delay_us_callback_register(NULL);
> > > +}
> > > diff --git a/lib/librte_eal/common/include/generic/rte_cycles.h
> > > b/lib/librte_eal/common/include/generic/rte_cycles.h
> > > index 8cc21f2..7a45b58 100644
> > > --- a/lib/librte_eal/common/include/generic/rte_cycles.h
> > > +++ b/lib/librte_eal/common/include/generic/rte_cycles.h
> > > @@ -182,13 +182,16 @@ rte_get_timer_hz(void) }
> > >
> > > /**
> > > + *
> >
> > useless newline
> >
> > > * Wait at least us microseconds.
> > > + * This function can be replaced with user-defined function using
> > > + * rte_delay_us_callback_register
> >
> > I think you can use @see to point to rte_delay_us_callback_register.
> >
> > > *
> > > * @param us
> > > * The number of microseconds to wait.
> > > */
> > > void
> > > -rte_delay_us(unsigned us);
> > > +(*rte_delay_us)(unsigned us);
> > >
> > > /**
> > > * Wait at least ms milliseconds.
> > > @@ -202,4 +205,14 @@ rte_delay_ms(unsigned ms)
> > > rte_delay_us(ms * 1000);
> > > }
> > >
> > > +/**
> > > + * Replace rte_delay_us with user defined function.
> > > + *
> > > + * @param userfunc
> > > + * User function which replaces rte_delay_us. NULL restores
> > > + * buildin block delay function.
> >
> > buildin -> builtin ?
> >
> > > + */
> > > +void rte_delay_us_callback_register(void(*userfunc)(unsigned));
> >
>
>
next prev parent reply other threads:[~2016-09-22 15:08 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-07-20 12:10 jozmarti
2016-09-13 20:04 ` Thomas Monjalon
2016-09-21 13:12 ` Thomas Monjalon
2016-09-22 8:37 ` Jozef Martiniak -X (jozmarti - PANTHEON TECHNOLOGIES at Cisco)
2016-09-22 15:08 ` Thomas Monjalon [this message]
2016-09-23 6:39 ` [dpdk-dev] [PATCH v3] " jozmarti
2016-09-23 14:03 ` Thomas Monjalon
2016-09-26 8:35 ` jozmarti
2016-09-26 12:48 ` Thomas Monjalon
-- strict thread matches above, loose matches on Subject: below --
2016-07-19 12:42 [dpdk-dev] [PATCH] " jozmarti
2016-07-19 13:17 ` Wiles, Keith
2016-07-19 13:21 ` Thomas Monjalon
2016-07-19 13:52 ` Jozef Martiniak -X (jozmarti - PANTHEON TECHNOLOGIES at Cisco)
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