From: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
To: Oleg Babin <obabin@virtuozzo.com>
Cc: netdev@vger.kernel.org, linux-sctp@vger.kernel.org,
"David S. Miller" <davem@davemloft.net>,
Vlad Yasevich <vyasevich@gmail.com>,
Neil Horman <nhorman@tuxdriver.com>,
Xin Long <lucien.xin@gmail.com>,
Andrey Ryabinin <aryabinin@virtuozzo.com>
Subject: Re: [PATCH net-next 0/2] net/sctp: Avoid allocating high order memory with kmalloc()
Date: Mon, 23 Apr 2018 18:33:15 -0300 [thread overview]
Message-ID: <20180423213314.GG3711@localhost.localdomain> (raw)
In-Reply-To: <1524508866-317485-1-git-send-email-obabin@virtuozzo.com>
Hi,
On Mon, Apr 23, 2018 at 09:41:04PM +0300, Oleg Babin wrote:
> Each SCTP association can have up to 65535 input and output streams.
> For each stream type an array of sctp_stream_in or sctp_stream_out
> structures is allocated using kmalloc_array() function. This function
> allocates physically contiguous memory regions, so this can lead
> to allocation of memory regions of very high order, i.e.:
>
> sizeof(struct sctp_stream_out) == 24,
> ((65535 * 24) / 4096) == 383 memory pages (4096 byte per page),
> which means 9th memory order.
>
> This can lead to a memory allocation failures on the systems
> under a memory stress.
Did you do performance tests while actually using these 65k streams
and with 256 (so it gets 2 pages)?
This will introduce another deref on each access to an element, but
I'm not expecting any impact due to it.
Marcelo
next prev parent reply other threads:[~2018-04-23 21:33 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-04-23 18:41 [PATCH net-next 0/2] net/sctp: Avoid allocating high order memory with kmalloc() Oleg Babin
2018-04-23 18:41 ` [PATCH net-next 1/2] net/sctp: Make wrappers for accessing in/out streams Oleg Babin
2018-04-23 21:33 ` Marcelo Ricardo Leitner
2018-04-26 22:19 ` Oleg Babin
2018-04-23 18:41 ` [PATCH net-next 2/2] net/sctp: Replace in/out stream arrays with flex_array Oleg Babin
2018-04-23 21:33 ` Marcelo Ricardo Leitner [this message]
2018-04-26 22:14 ` [PATCH net-next 0/2] net/sctp: Avoid allocating high order memory with kmalloc() Oleg Babin
2018-04-26 22:28 ` Marcelo Ricardo Leitner
2018-04-26 22:45 ` Oleg Babin
2018-07-24 15:35 ` Konstantin Khorenko
2018-07-24 17:36 ` Marcelo Ricardo Leitner
2018-08-03 16:21 ` [PATCH v2 " Konstantin Khorenko
2018-08-03 16:21 ` [PATCH v2 1/2] net/sctp: Make wrappers for accessing in/out streams Konstantin Khorenko
2018-08-03 16:41 ` David Laight
2018-08-03 19:50 ` David Miller
2018-08-09 8:39 ` Konstantin Khorenko
2018-08-03 20:40 ` Marcelo Ricardo Leitner
2018-08-09 8:40 ` Konstantin Khorenko
2018-08-03 16:21 ` [PATCH v2 2/2] net/sctp: Replace in/out stream arrays with flex_array Konstantin Khorenko
2018-08-03 16:43 ` [PATCH v2 0/2] net/sctp: Avoid allocating high order memory with kmalloc() David Laight
2018-08-03 20:30 ` Marcelo Ricardo Leitner
2018-08-03 20:56 ` Michael Tuexen
2018-08-06 9:34 ` David Laight
2018-08-08 14:48 ` Marcelo Ricardo Leitner
2018-08-03 23:36 ` Marcelo Ricardo Leitner
2018-08-09 8:43 ` Konstantin Khorenko
2018-08-10 17:03 ` Konstantin Khorenko
2018-08-10 17:11 ` [PATCH v3 " Konstantin Khorenko
2018-08-10 17:11 ` [PATCH v3 1/2] net/sctp: Make wrappers for accessing in/out streams Konstantin Khorenko
2018-08-10 17:11 ` [PATCH v3 2/2] net/sctp: Replace in/out stream arrays with flex_array Konstantin Khorenko
2018-08-11 19:36 ` [PATCH v3 0/2] net/sctp: Avoid allocating high order memory with kmalloc() David Miller
2018-08-10 17:41 ` [PATCH v2 " Marcelo Ricardo Leitner
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