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From: "Joyce Kong (Arm Technology China)" <Joyce.Kong@arm.com>
To: "jerinj@marvell.com" <jerinj@marvell.com>, "dev@dpdk.org" <dev@dpdk.org>
Cc: "stephen@networkplumber.org" <stephen@networkplumber.org>,
	Honnappa Nagarahalli <Honnappa.Nagarahalli@arm.com>,
	"thomas@monjalon.net" <thomas@monjalon.net>, nd <nd@arm.com>,
	"jerin.jacob@caviumnetworks.com" <jerin.jacob@caviumnetworks.com>,
	"Gavin Hu (Arm Technology China)" <Gavin.Hu@arm.com>
Subject: Re: [dpdk-dev] [PATCH v5 1/2] eal/ticketlock: ticket based to improve fairness
Date: Fri, 15 Mar 2019 06:58:12 +0000	[thread overview]
Message-ID: <AM0PR08MB3587F51A1DC4AF25DDF4A62092440@AM0PR08MB3587.eurprd08.prod.outlook.com> (raw)
In-Reply-To: <2d837f0c69c6255abe8c113cf89cc2b0414ca202.camel@marvell.com>

> -----Original Message-----
> From: Jerin Jacob Kollanukkaran <jerinj@marvell.com>
> Sent: Wednesday, March 13, 2019 11:36 PM
> To: Joyce Kong (Arm Technology China) <Joyce.Kong@arm.com>;
> dev@dpdk.org
> Cc: stephen@networkplumber.org; Honnappa Nagarahalli
> <Honnappa.Nagarahalli@arm.com>; thomas@monjalon.net; nd
> <nd@arm.com>; jerin.jacob@caviumnetworks.com; Gavin Hu (Arm
> Technology China) <Gavin.Hu@arm.com>
> Subject: Re: [dpdk-dev] [PATCH v5 1/2] eal/ticketlock: ticket based to improve
> fairness
> 
> On Mon, 2019-03-11 at 13:52 +0800, Joyce Kong wrote:
> > The spinlock implementation is unfair, some threads may take locks
> > aggressively while leaving the other threads starving for long time.
> >
> > This patch introduces ticketlock which gives each waiting thread a
> > ticket and they can take the lock one by one. First come, first
> > serviced.
> > This avoids starvation for too long time and is more predictable.
> >
> > Suggested-by: Jerin Jacob <jerinj@marvell.com>
> > Signed-off-by: Joyce kong <joyce.kong@arm.com>
> > Reviewed-by: Gavin Hu <gavin.hu@arm.com>
> > Reviewed-by: Ola Liljedahl <ola.liljedahl@arm.com>
> > Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
> > ---
> > diff --git a/MAINTAINERS b/MAINTAINERS index 097cfb4..12a091f 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -210,6 +210,10 @@ M: Cristian Dumitrescu <
> > cristian.dumitrescu@intel.com>
> >  F: lib/librte_eal/common/include/rte_bitmap.h
> >  F: app/test/test_bitmap.c
> >
> > +Ticketlock
> > +M: Joyce Kong <joyce.kong@arm.com>
> > +F: lib/librte_eal/common/include/generic/rte_ticketlock.h
> 
> 
> Add F: app/test/test_ticketlock.c in the next patch
> 

Done in V6.


> >
> > +#include <rte_lcore.h>
> > +#include <rte_common.h>
> > +#include <rte_pause.h>
> 
> Sort the header in alphabetical order.
> 

Done in v6.


> > +
> > +/**
> > + * The rte_ticketlock_t type.
> > + */
> > +typedef struct {
> > +	uint16_t current;
> > +	uint16_t next;
> > +} rte_ticketlock_t;
> > +
> >
> > +
> > +/**
> > + * Take the ticketlock.
> > + *
> > + * @param tl
> > + *   A pointer to the ticketlock.
> > + */
> > +static inline __rte_experimental void
> > +rte_ticketlock_lock(rte_ticketlock_t *tl) {
> > +	unsigned int me = __atomic_fetch_add(&tl->next, 1,
> 
> If current, next is uint16_t why "me" as unsigned int.
> 
 
Change "me" to uint16_t to match current and next in v6.


> > __ATOMIC_RELAXED);
> > +	while (__atomic_load_n(&tl->current, __ATOMIC_ACQUIRE) != me)
> > +		rte_pause();
> > +}
> > +
> > +/**
> > + * Release the ticketlock.
> > + *
> > + * @param tl
> > + *   A pointer to the ticketlock.
> > + */
> > +static inline __rte_experimental void
> > +rte_ticketlock_unlock(rte_ticketlock_t *tl) {
> > +	unsigned int i = __atomic_load_n(&tl->current,
> > __ATOMIC_RELAXED);
> > +	i++;
> 
> You can save this line by making
> __atomic_store_n(&tl->current, i + 1, __ATOMIC_RELEASE);
> 

Done in V6.


> The code looks good. Please check the above comments and earlier reported
> compilation issue with clang 7.1
> 


  reply	other threads:[~2019-03-15  6:58 UTC|newest]

Thread overview: 74+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-01-13 14:46 [dpdk-dev] [PATCH v1] ticketlock: " Gavin Hu
2019-01-14  7:59 ` [dpdk-dev] [EXT] " Jerin Jacob Kollanukkaran
2019-01-14 16:57   ` Gavin Hu (Arm Technology China)
2019-01-14 23:36 ` [dpdk-dev] " Honnappa Nagarahalli
2019-01-18  9:15 ` [dpdk-dev] [PATCH v2 1/2] " Joyce Kong
2019-01-25  8:37   ` [dpdk-dev] [PATCH v3 0/2] ticketlock: implement ticketlock and add test case Joyce Kong
2019-02-19 10:48     ` [dpdk-dev] [PATCH v4 " Joyce Kong
2019-03-11  5:52       ` [dpdk-dev] [PATCH v5 " Joyce Kong
2019-02-19 10:48     ` [dpdk-dev] [PATCH v4 1/2] ticketlock: ticket based to improve fairness Joyce Kong
2019-03-11  5:52       ` [dpdk-dev] [PATCH v5 1/2] eal/ticketlock: " Joyce Kong
2019-03-13  9:41         ` Jerin Jacob Kollanukkaran
2019-03-15  6:57           ` Joyce Kong (Arm Technology China)
2019-03-15  6:57             ` Joyce Kong (Arm Technology China)
2019-03-13 15:36         ` Jerin Jacob Kollanukkaran
2019-03-15  6:58           ` Joyce Kong (Arm Technology China) [this message]
2019-03-15  6:58             ` Joyce Kong (Arm Technology China)
2019-02-19 10:48     ` [dpdk-dev] [PATCH v4 2/2] test/ticketlock: add ticket lock test case Joyce Kong
2019-03-11  5:52       ` [dpdk-dev] [PATCH v5 " Joyce Kong
2019-03-13 13:31         ` Jerin Jacob Kollanukkaran
2019-03-15  6:57           ` Joyce Kong (Arm Technology China)
2019-03-15  6:57             ` Joyce Kong (Arm Technology China)
2019-01-25  8:37   ` [dpdk-dev] [PATCH v3 1/2] ticketlock: ticket based to improve fairness Joyce Kong
2019-01-25  8:37   ` [dpdk-dev] [PATCH v3 2/2] test/ticketlock: add ticket lock test case Joyce Kong
2019-03-15  6:56   ` [dpdk-dev] [PATCH v6 0/2] ticketlock: implement ticketlock and add " Joyce Kong
2019-03-15  6:56     ` Joyce Kong
2019-03-15  6:56   ` [dpdk-dev] [PATCH v6 1/2] eal/ticketlock: ticket based to improve fairness Joyce Kong
2019-03-15  6:56     ` Joyce Kong
2019-03-15 12:55     ` Ananyev, Konstantin
2019-03-15 12:55       ` Ananyev, Konstantin
2019-03-19  9:44       ` Gavin Hu (Arm Technology China)
2019-03-19  9:44         ` Gavin Hu (Arm Technology China)
2019-03-19 10:15         ` Ananyev, Konstantin
2019-03-19 10:15           ` Ananyev, Konstantin
2019-03-20  5:11           ` Gavin Hu (Arm Technology China)
2019-03-20  5:11             ` Gavin Hu (Arm Technology China)
2019-03-20  9:47             ` Ananyev, Konstantin
2019-03-20  9:47               ` Ananyev, Konstantin
2019-03-22  2:04               ` Gavin Hu (Arm Technology China)
2019-03-22  2:04                 ` Gavin Hu (Arm Technology China)
2019-03-15  6:56   ` [dpdk-dev] [PATCH v6 2/2] test/ticketlock: add ticket lock test case Joyce Kong
2019-03-15  6:56     ` Joyce Kong
2019-03-21  9:13   ` [dpdk-dev] [PATCH v7 0/3] ticketlock: implement ticketlock and add " Joyce Kong
2019-03-21  9:13     ` Joyce Kong
2019-03-21  9:13   ` [dpdk-dev] [PATCH v7 2/3] eal/ticketlock: enable generic ticketlock on all arch Joyce Kong
2019-03-21  9:13     ` Joyce Kong
2019-03-21  9:13   ` [dpdk-dev] [PATCH v7 3/3] test/ticketlock: add ticket lock test case Joyce Kong
2019-03-21  9:13     ` Joyce Kong
2019-03-22 11:38     ` Ananyev, Konstantin
2019-03-22 11:38       ` Ananyev, Konstantin
2019-03-25 10:25       ` Joyce Kong (Arm Technology China)
2019-03-25 10:25         ` Joyce Kong (Arm Technology China)
2019-03-21  9:15   ` [dpdk-dev] [PATCH v7 1/3] eal/ticketlock: ticket based to improve fairness Joyce Kong
2019-03-21  9:15     ` Joyce Kong
2019-03-22 10:56     ` Ananyev, Konstantin
2019-03-22 10:56       ` Ananyev, Konstantin
2019-03-25 11:11   ` [dpdk-dev] [PATCH v8 0/3] ticketlock: implement ticketlock and add test case Joyce Kong
2019-03-25 11:11     ` Joyce Kong
2019-03-27 11:20     ` Ananyev, Konstantin
2019-03-27 11:20       ` Ananyev, Konstantin
2019-03-28 14:02       ` Thomas Monjalon
2019-03-28 14:02         ` Thomas Monjalon
2019-03-25 11:11   ` [dpdk-dev] [PATCH v8 1/3] eal/ticketlock: ticket based to improve fairness Joyce Kong
2019-03-25 11:11     ` Joyce Kong
2019-03-25 11:11   ` [dpdk-dev] [PATCH v8 2/3] eal/ticketlock: enable generic ticketlock on all arch Joyce Kong
2019-03-25 11:11     ` Joyce Kong
2019-03-25 11:11   ` [dpdk-dev] [PATCH v8 3/3] test/ticketlock: add ticket lock test case Joyce Kong
2019-03-25 11:11     ` Joyce Kong
2019-04-08 20:18     ` David Marchand
2019-04-08 20:18       ` David Marchand
2019-04-14 20:37       ` Thomas Monjalon
2019-04-14 20:37         ` Thomas Monjalon
2019-04-15  9:07         ` Joyce Kong (Arm Technology China)
2019-04-15  9:07           ` Joyce Kong (Arm Technology China)
2019-01-18  9:15 ` [dpdk-dev] [PATCH v2 2/2] " Joyce Kong

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