patches for DPDK stable branches
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From: santosh <santosh.shukla@caviumnetworks.com>
To: Andrew Rybchenko <arybchenko@solarflare.com>,
	Olivier Matz <olivier.matz@6wind.com>
Cc: dev@dpdk.org, stable@dpdk.org, jerin.jacob@caviumnetworks.com
Subject: Re: [dpdk-stable] [RFC v2 01/17] mempool: fix phys contig check if populate default skipped
Date: Thu, 1 Feb 2018 14:39:49 +0530	[thread overview]
Message-ID: <90005aad-1508-44bc-92a4-7c5d5f7b0246@caviumnetworks.com> (raw)
In-Reply-To: <b10db3a0-0b41-af79-279f-1a967823fe8d@solarflare.com>


On Thursday 01 February 2018 12:24 PM, Andrew Rybchenko wrote:
> On 02/01/2018 08:05 AM, santosh wrote:
>> On Wednesday 31 January 2018 10:15 PM, Olivier Matz wrote:
>>> On Tue, Jan 23, 2018 at 01:15:56PM +0000, Andrew Rybchenko wrote:
>>>> There is not specified dependency between rte_mempool_populate_default()
>>>> and rte_mempool_populate_iova(). So, the second should not rely on the
>>>> fact that the first adds capability flags to the mempool flags.
>>>>
>>>> Fixes: 65cf769f5e6a ("mempool: detect physical contiguous objects")
>>>> Cc: stable@dpdk.org
>>>>
>>>> Signed-off-by: Andrew Rybchenko <arybchenko@solarflare.com>
>>> Looks good to me. I agree it's strange that the mp->flags are
>>> updated with capabilities only in rte_mempool_populate_default().
>>> I see that this behavior is removed later in the patchset since the
>>> get_capa() is removed!
>>>
>>> However maybe this single patch could go in 18.02.
>>> +Santosh +Jerin since it's mostly about Octeon.
>> rte_mempool_xmem_size should return correct size if MEMPOOL_F_CAPA_BLK_ALIGNED_OBJECTS flag
>> is set in 'mp->flags'. Thats why _ops_get_capabilities() called in _populate_default() but not
>> at _populate_iova().
>> I think, this 'alone' patch may break octeontx mempool.
>
> The patch does not touch rte_mempool_populate_default().
> _ops_get_capabilities() is still called there before
> rte_mempool_xmem_size(). The theoretical problem which
> the patch tries to fix is the case when
> rte_mempool_populate_default() is not called at all. I.e. application
> calls _ops_get_capabilities() to get flags, then, together with
> mp->flags, calls rte_mempool_xmem_size() directly, allocates
> calculated amount of memory and calls _populate_iova().
>
In that case, Application does like below:

	/* Get mempool capabilities */
	mp_flags = 0;
	ret = rte_mempool_ops_get_capabilities(mp, &mp_flags);
	if ((ret < 0) && (ret != -ENOTSUP))
		return ret;

	/* update mempool capabilities */
	mp->flags |= mp_flags;

	/* calc xmem sz */
	size = rte_mempool_xmem_size(n, total_elt_sz, pg_shift,
					mp->flags);

	/* rsrv memory */
	mz = rte_memzone_reserve_aligned(mz_name, size,...);

	/* now populate iova */
	ret = rte_mempool_populate_iova(mp,,..);

won't it work?

However I understand that clubbing `_get_ops_capa() + flag-updation` into _populate_iova()
perhaps better from user PoV.

> Since later patches of the series reconsider memory size
> calculation etc, it is up to you if it makes sense to apply it
> in 18.02 as a fix.
>

  reply	other threads:[~2018-02-01  9:10 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <1511539591-20966-1-git-send-email-arybchenko@solarflare.com>
     [not found] ` <1516713372-10572-1-git-send-email-arybchenko@solarflare.com>
2018-01-23 13:15   ` Andrew Rybchenko
2018-01-31 16:45     ` Olivier Matz
2018-02-01  5:05       ` santosh
2018-02-01  6:54         ` Andrew Rybchenko
2018-02-01  9:09           ` santosh [this message]
2018-02-01  9:18             ` [dpdk-stable] [dpdk-dev] " Andrew Rybchenko
2018-02-01  9:30               ` santosh
2018-02-01 10:00                 ` Andrew Rybchenko
2018-02-01 10:14                   ` Olivier Matz
2018-02-01 10:33                     ` santosh
2018-02-01 14:02                       ` Andrew Rybchenko
2018-02-01 10:17                   ` santosh
2018-02-01 14:02     ` [dpdk-stable] [PATCH] " Andrew Rybchenko
2018-02-05 23:53       ` Thomas Monjalon
     [not found]   ` <1521994855-8808-1-git-send-email-arybchenko@solarflare.com>
2018-03-25 16:20     ` [dpdk-stable] [PATCH v2 01/11] mempool: fix memhdr leak when no objects are populated Andrew Rybchenko
     [not found]   ` <1522080591-24705-1-git-send-email-arybchenko@solarflare.com>
2018-03-26 16:09     ` [dpdk-stable] [PATCH v3 " Andrew Rybchenko
2018-04-06 15:50       ` Olivier Matz
     [not found] ` <1523885080-17168-1-git-send-email-arybchenko@solarflare.com>
2018-04-16 13:24   ` [dpdk-stable] [PATCH v4 " Andrew Rybchenko

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