From: Feifei Wang <Feifei.Wang2@arm.com>
To: "Ananyev, Konstantin" <konstantin.ananyev@intel.com>,
Ruifeng Wang <Ruifeng.Wang@arm.com>
Cc: "dev@dpdk.org" <dev@dpdk.org>, nd <nd@arm.com>, nd <nd@arm.com>
Subject: [dpdk-dev] 回复: [RFC PATCH v3 1/5] eal: add new definitions for wait scheme
Date: Tue, 12 Oct 2021 08:09:47 +0000 [thread overview]
Message-ID: <DB9PR08MB6923C02888AAD5294CC992D8C8B69@DB9PR08MB6923.eurprd08.prod.outlook.com> (raw)
In-Reply-To: <DM6PR11MB44919E4C4EC5D4DE04ECAB6D9AB19@DM6PR11MB4491.namprd11.prod.outlook.com>
> -----邮件原件-----
> 发件人: Ananyev, Konstantin <konstantin.ananyev@intel.com>
> 发送时间: Friday, October 8, 2021 12:19 AM
> 收件人: Feifei Wang <Feifei.Wang2@arm.com>; Ruifeng Wang
> <Ruifeng.Wang@arm.com>
> 抄送: dev@dpdk.org; nd <nd@arm.com>
> 主题: RE: [dpdk-dev] [RFC PATCH v3 1/5] eal: add new definitions for wait
> scheme
[snip]
> > diff --git a/lib/eal/include/generic/rte_pause.h
> > b/lib/eal/include/generic/rte_pause.h
> > index 668ee4a184..4e32107eca 100644
> > --- a/lib/eal/include/generic/rte_pause.h
> > +++ b/lib/eal/include/generic/rte_pause.h
> > @@ -111,6 +111,84 @@ rte_wait_until_equal_64(volatile uint64_t *addr,
> uint64_t expected,
> > while (__atomic_load_n(addr, memorder) != expected)
> > rte_pause();
> > }
> > +
> > +/*
> > + * Wait until a 16-bit *addr breaks the condition, with a relaxed
> > +memory
> > + * ordering model meaning the loads around this API can be reordered.
> > + *
> > + * @param addr
> > + * A pointer to the memory location.
> > + * @param mask
> > + * A mask of value bits in interest
> > + * @param expected
> > + * A 16-bit expected value to be in the memory location.
> > + * @param cond
> > + * A symbol representing the condition (==, !=).
> > + * @param memorder
> > + * Two different memory orders that can be specified:
> > + * __ATOMIC_ACQUIRE and __ATOMIC_RELAXED. These map to
> > + * C++11 memory orders with the same names, see the C++11 standard
> > +or
> > + * the GCC wiki on atomic synchronization for detailed definition.
> > + */
>
> Hmm, so now we have 2 APIs doing similar thing:
> rte_wait_until_equal_n() and rte_wait_event_n().
> Can we probably unite them somehow?
> At least make rte_wait_until_equal_n() to use rte_wait_event_n() underneath.
>
You are right. We plan to change rte_wait_until_equal API after this new scheme
is achieved. And then, we will merge wait_unil into wait_event definition in the next new
patch series.
> > +#define rte_wait_event_16(addr, mask, expected, cond, memorder)
> \
> > +do { \
> > + assert(memorder == __ATOMIC_ACQUIRE || memorder ==
> > +__ATOMIC_RELAXED); \
>
> And why user is not allowed to use __ATOMIC_SEQ_CST here?
Actually this is just a load operation, and acquire here is enough to make sure 'load
addr value' can be before other operations.
> BTW, if we expect memorder to always be a constant, might be better
> BUILD_BUG_ON()?
If I understand correctly, you means we can replace 'assert' by 'build_bug_on':
RTE_BUILD_BUG_ON(memorder != __ATOMIC_ACQUIRE && memorder !=__ATOMIC_RELAXED);
>
> > + \
> > + while ((__atomic_load_n(addr, memorder) & mask) cond expected)
> \
> > + rte_pause(); \
> > +} while (0)
>
> Two thoughts with these macros:
> 1. It is a goof practise to put () around macro parameters in the macro body.
> Will save from a lot of unexpected troubles.
> 2. I think these 3 macros can be united into one.
> Something like:
>
> #define rte_wait_event(addr, mask, expected, cond, memorder) do {\
> typeof (*(addr)) val = __atomic_load_n((addr), (memorder)); \
> if ((val & (typeof(val))(mask)) cond (typeof(val))(expected)) \
> break; \
> rte_pause(); \
> } while (1);
For this point, I think it is due to different size need to use different assembly instructions
in arm architecture. For example,
load 16 bits instruction is "ldxrh %w[tmp], [%x[addr]"
load 32 bits instruction is " ldxr %w[tmp], [%x[addr]"
load 64 bits instruction is " ldxr %x[tmp], [%x[addr] "
And for consistency, we also use 3 APIs in generic path.
>
>
> > +
> > +/*
> > + * Wait until a 32-bit *addr breaks the condition, with a relaxed
> > +memory
> > + * ordering model meaning the loads around this API can be reordered.
> > + *
> > + * @param addr
> > + * A pointer to the memory location.
> > + * @param mask
> > + * A mask of value bits in interest.
> > + * @param expected
> > + * A 32-bit expected value to be in the memory location.
> > + * @param cond
> > + * A symbol representing the condition (==, !=).
> > + * @param memorder
> > + * Two different memory orders that can be specified:
> > + * __ATOMIC_ACQUIRE and __ATOMIC_RELAXED. These map to
> > + * C++11 memory orders with the same names, see the C++11 standard
> > +or
> > + * the GCC wiki on atomic synchronization for detailed definition.
> > + */
> > +#define rte_wait_event_32(addr, mask, expected, cond, memorder)
> \
> > +do { \
> > + assert(memorder == __ATOMIC_ACQUIRE || memorder ==
> __ATOMIC_RELAXED); \
> > + \
> > + while ((__atomic_load_n(addr, memorder) & mask) cond expected)
> \
> > + rte_pause(); \
> > +} while (0)
> > +
> > +/*
> > + * Wait until a 64-bit *addr breaks the condition, with a relaxed
> > +memory
> > + * ordering model meaning the loads around this API can be reordered.
> > + *
> > + * @param addr
> > + * A pointer to the memory location.
> > + * @param mask
> > + * A mask of value bits in interest
> > + * @param expected
> > + * A 64-bit expected value to be in the memory location.
> > + * @param cond
> > + * A symbol representing the condition (==, !=).
> > + * @param memorder
> > + * Two different memory orders that can be specified:
> > + * __ATOMIC_ACQUIRE and __ATOMIC_RELAXED. These map to
> > + * C++11 memory orders with the same names, see the C++11 standard
> > +or
> > + * the GCC wiki on atomic synchronization for detailed definition.
> > + */
> > +#define rte_wait_event_64(addr, mask, expected, cond, memorder)
> \
> > +do { \
> > + assert(memorder == __ATOMIC_ACQUIRE || memorder ==
> __ATOMIC_RELAXED); \
> > + \
> > + while ((__atomic_load_n(addr, memorder) & mask) cond expected)
> \
> > + rte_pause(); \
> > +} while (0)
> > #endif
> >
> > #endif /* _RTE_PAUSE_H_ */
> > --
> > 2.25.1
next prev parent reply other threads:[~2021-10-12 8:10 UTC|newest]
Thread overview: 113+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-02 5:32 [dpdk-dev] [RFC PATCH v1 0/5] add new API for wait until scheme Feifei Wang
2021-09-02 5:32 ` [dpdk-dev] [RFC PATCH v1 1/5] eal: " Feifei Wang
2021-09-02 5:32 ` [dpdk-dev] [RFC PATCH v1 2/5] eal: use wait until scheme for read pflock Feifei Wang
2021-09-02 5:32 ` [dpdk-dev] [RFC PATCH v1 3/5] eal: use wait until scheme for mcslock Feifei Wang
2021-09-02 5:32 ` [dpdk-dev] [RFC PATCH v1 4/5] lib/bpf: use wait until scheme for Rx/Tx iteration Feifei Wang
2021-09-02 5:32 ` [dpdk-dev] [RFC PATCH v1 5/5] lib/distributor: use wait until scheme Feifei Wang
2021-09-02 15:22 ` [dpdk-dev] [RFC PATCH v1 0/5] add new API for " Stephen Hemminger
2021-09-03 7:02 ` [dpdk-dev] 回复: " Feifei Wang
2021-09-23 9:58 ` [dpdk-dev] [RFC PATCH v2 0/5] add new definitions for wait scheme Feifei Wang
2021-09-23 9:58 ` [dpdk-dev] [RFC PATCH v2 1/5] eal: " Feifei Wang
2021-09-23 9:58 ` [dpdk-dev] [RFC PATCH v2 2/5] eal: use wait event for read pflock Feifei Wang
2021-09-23 9:59 ` [dpdk-dev] [RFC PATCH v2 3/5] eal: use wait event scheme for mcslock Feifei Wang
2021-09-23 9:59 ` [dpdk-dev] [RFC PATCH v2 4/5] lib/bpf: use wait event scheme for Rx/Tx iteration Feifei Wang
2021-09-24 18:07 ` Ananyev, Konstantin
2021-09-26 2:19 ` [dpdk-dev] 回复: " Feifei Wang
2021-09-23 9:59 ` [dpdk-dev] [RFC PATCH v2 5/5] lib/distributor: use wait event scheme Feifei Wang
2021-09-26 6:32 ` [dpdk-dev] [RFC PATCH v3 0/5] add new definitions for wait scheme Feifei Wang
2021-09-26 6:32 ` [dpdk-dev] [RFC PATCH v3 1/5] eal: " Feifei Wang
2021-10-07 16:18 ` Ananyev, Konstantin
2021-10-12 8:09 ` Feifei Wang [this message]
2021-10-13 15:03 ` Ananyev, Konstantin
2021-10-13 17:00 ` Stephen Hemminger
2021-10-14 3:14 ` [dpdk-dev] 回复: " Feifei Wang
2021-10-14 3:08 ` Feifei Wang
2021-09-26 6:32 ` [dpdk-dev] [RFC PATCH v3 2/5] eal: use wait event for read pflock Feifei Wang
2021-09-26 6:33 ` [dpdk-dev] [RFC PATCH v3 3/5] eal: use wait event scheme for mcslock Feifei Wang
2021-09-26 6:33 ` [dpdk-dev] [RFC PATCH v3 4/5] lib/bpf: use wait event scheme for Rx/Tx iteration Feifei Wang
2021-10-07 15:50 ` Ananyev, Konstantin
2021-10-07 17:40 ` Ananyev, Konstantin
2021-10-20 6:20 ` [dpdk-dev] 回复: " Feifei Wang
2021-09-26 6:33 ` [dpdk-dev] [RFC PATCH v3 5/5] lib/distributor: use wait event scheme Feifei Wang
2021-10-20 8:45 ` [dpdk-dev] [PATCH v4 0/5] add new definitions for wait scheme Feifei Wang
2021-10-20 8:45 ` [dpdk-dev] [PATCH v4 1/5] eal: " Feifei Wang
2021-10-21 16:24 ` Ananyev, Konstantin
2021-10-25 9:20 ` [dpdk-dev] 回复: " Feifei Wang
2021-10-25 14:28 ` [dpdk-dev] " Ananyev, Konstantin
2021-10-26 1:08 ` [dpdk-dev] 回复: " Feifei Wang
2021-10-22 0:10 ` [dpdk-dev] " Jerin Jacob
2021-10-25 9:30 ` [dpdk-dev] 回复: " Feifei Wang
2021-10-25 9:43 ` [dpdk-dev] " Jerin Jacob
2021-10-26 1:11 ` [dpdk-dev] 回复: " Feifei Wang
2021-10-20 8:45 ` [dpdk-dev] [PATCH v4 2/5] eal: use wait event for read pflock Feifei Wang
2021-10-20 8:45 ` [dpdk-dev] [PATCH v4 3/5] eal: use wait event scheme for mcslock Feifei Wang
2021-10-20 8:45 ` [dpdk-dev] [PATCH v4 4/5] lib/bpf: use wait event scheme for Rx/Tx iteration Feifei Wang
2021-10-20 8:45 ` [dpdk-dev] [PATCH v4 5/5] lib/distributor: use wait event scheme Feifei Wang
2021-10-26 8:01 ` [dpdk-dev] [PATCH v5 0/5] add new definitions for wait scheme Feifei Wang
2021-10-26 8:02 ` [dpdk-dev] [PATCH v5 1/5] eal: " Feifei Wang
2021-10-26 8:08 ` [dpdk-dev] 回复: " Feifei Wang
2021-10-26 9:46 ` [dpdk-dev] " Ananyev, Konstantin
2021-10-26 9:59 ` Ananyev, Konstantin
2021-10-27 6:56 ` [dpdk-dev] 回复: " Feifei Wang
2021-10-26 8:02 ` [dpdk-dev] [PATCH v5 2/5] eal: use wait event for read pflock Feifei Wang
2021-10-26 8:02 ` [dpdk-dev] [PATCH v5 3/5] eal: use wait event scheme for mcslock Feifei Wang
2021-10-26 8:02 ` [dpdk-dev] [PATCH v5 4/5] lib/bpf: use wait event scheme for Rx/Tx iteration Feifei Wang
2021-10-26 8:18 ` [dpdk-dev] 回复: " Feifei Wang
2021-10-26 9:43 ` [dpdk-dev] " Ananyev, Konstantin
2021-10-26 12:56 ` Ananyev, Konstantin
2021-10-27 7:04 ` [dpdk-dev] 回复: " Feifei Wang
2021-10-27 7:31 ` Feifei Wang
2021-10-27 14:47 ` [dpdk-dev] " Ananyev, Konstantin
2021-10-28 6:24 ` [dpdk-dev] 回复: " Feifei Wang
2021-10-26 8:02 ` [dpdk-dev] [PATCH v5 5/5] lib/distributor: use wait event scheme Feifei Wang
2021-10-27 8:10 ` [dpdk-dev] [PATCH v6 0/4] add new definitions for wait scheme Feifei Wang
2021-10-27 8:10 ` [dpdk-dev] [PATCH v6 1/4] eal: " Feifei Wang
2021-10-27 8:10 ` [dpdk-dev] [PATCH v6 2/4] eal: use wait event for read pflock Feifei Wang
2021-10-27 8:10 ` [dpdk-dev] [PATCH v6 3/4] eal: use wait event scheme for mcslock Feifei Wang
2021-10-27 11:16 ` Mattias Rönnblom
2021-10-28 6:32 ` [dpdk-dev] 回复: " Feifei Wang
2021-10-27 8:10 ` [dpdk-dev] [PATCH v6 4/4] lib/distributor: use wait event scheme Feifei Wang
2021-10-27 10:57 ` [dpdk-dev] [PATCH v6 0/4] add new definitions for wait scheme Jerin Jacob
2021-10-28 6:33 ` [dpdk-dev] 回复: " Feifei Wang
2021-10-28 6:56 ` [dpdk-dev] [PATCH v7 0/5] " Feifei Wang
2021-10-28 6:56 ` [dpdk-dev] [PATCH v7 1/5] eal: " Feifei Wang
2021-10-28 7:15 ` Jerin Jacob
2021-10-28 7:40 ` [dpdk-dev] 回复: " Feifei Wang
2021-10-28 7:51 ` [dpdk-dev] " Jerin Jacob
2021-10-28 9:27 ` [dpdk-dev] 回复: " Feifei Wang
2021-10-28 13:14 ` [dpdk-dev] " Ananyev, Konstantin
2021-10-28 6:56 ` [dpdk-dev] [PATCH v7 2/5] eal: use wait event for read pflock Feifei Wang
2021-10-28 6:56 ` [dpdk-dev] [PATCH v7 3/5] eal: use wait event scheme for mcslock Feifei Wang
2021-10-28 7:02 ` Jerin Jacob
2021-10-28 7:14 ` [dpdk-dev] 回复: " Feifei Wang
2021-10-28 6:56 ` [dpdk-dev] [PATCH v7 4/5] lib/bpf: use wait event scheme for Rx/Tx iteration Feifei Wang
2021-10-28 13:15 ` Ananyev, Konstantin
2021-10-28 6:56 ` [dpdk-dev] [PATCH v7 5/5] lib/distributor: use wait event scheme Feifei Wang
2021-10-29 8:20 ` [dpdk-dev] [PATCH v8 0/5] add new definitions for wait scheme Feifei Wang
2021-10-29 8:20 ` [dpdk-dev] [PATCH v8 1/5] eal: " Feifei Wang
2021-10-29 13:54 ` Jerin Jacob
2021-10-31 8:38 ` David Marchand
2021-11-01 2:29 ` [dpdk-dev] 回复: " Feifei Wang
2021-10-29 8:20 ` [dpdk-dev] [PATCH v8 2/5] eal: use wait event for read pflock Feifei Wang
2021-10-29 13:55 ` Jerin Jacob
2021-10-31 8:37 ` David Marchand
2021-10-29 8:20 ` [dpdk-dev] [PATCH v8 3/5] eal: use wait event scheme for mcslock Feifei Wang
2021-10-29 13:55 ` Jerin Jacob
2021-10-31 8:37 ` David Marchand
2021-10-29 8:20 ` [dpdk-dev] [PATCH v8 4/5] lib/bpf: use wait event scheme for Rx/Tx iteration Feifei Wang
2021-10-31 8:37 ` David Marchand
2021-10-29 8:20 ` [dpdk-dev] [PATCH v8 5/5] lib/distributor: use wait event scheme Feifei Wang
2021-10-29 13:58 ` Jerin Jacob
2021-10-31 8:38 ` David Marchand
2021-11-01 12:44 ` David Hunt
2021-11-01 6:00 ` [dpdk-dev] [PATCH v9 0/5] add new helper for wait scheme Feifei Wang
2021-11-01 6:00 ` [dpdk-dev] [PATCH v9 1/5] eal: add a new generic " Feifei Wang
2021-11-01 6:00 ` [dpdk-dev] [PATCH v9 2/5] pflock: use wait until scheme for read pflock Feifei Wang
2021-11-03 14:46 ` David Marchand
2021-11-04 1:24 ` [dpdk-dev] 回复: " Feifei Wang
2021-11-01 6:00 ` [dpdk-dev] [PATCH v9 3/5] mcslock: use wait until scheme for mcslock Feifei Wang
2021-11-01 6:00 ` [dpdk-dev] [PATCH v9 4/5] bpf: use wait until scheme for Rx/Tx iteration Feifei Wang
2021-11-01 6:00 ` [dpdk-dev] [PATCH v9 5/5] distributor: use wait until scheme Feifei Wang
2021-11-01 16:05 ` Pattan, Reshma
2021-11-02 2:00 ` [dpdk-dev] 回复: " Feifei Wang
2021-11-03 14:55 ` [dpdk-dev] [PATCH v9 0/5] add new helper for wait scheme David Marchand
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