From: Daniel Borkmann <dborkman@redhat.com>
To: David Laight <David.Laight@ACULAB.COM>
Cc: davem@davemloft.net, netdev@vger.kernel.org, linux-sctp@vger.kernel.org
Subject: Re: [PATCH net-next 4/9] net: sctp: sctp_outq: consolidate chars into bitfield
Date: Wed, 17 Apr 2013 11:26:21 +0200 [thread overview]
Message-ID: <516E6ABD.2040904@redhat.com> (raw)
In-Reply-To: <AE90C24D6B3A694183C094C60CF0A2F6026B71DC@saturn3.aculab.com>
On 04/17/2013 10:43 AM, David Laight wrote:
>> __u32 outstanding_bytes;
>>
>> - /* Are we doing fast-rtx on this queue */
>> - char fast_rtx;
>> -
>> - /* Corked? */
>> - char cork;
>> -
>> - /* Is this structure empty? */
>> - char empty;
>> + __u8 fast_rtx:1, /* Are we doing fast-rtx on this queue */
>> + cork:1, /* Corked? */
>> + empty:1; /* Is this structure empty? */
>> };
>
> Use of bitfields just makes the code slower.
> The only real excuse for using them is to reduce the size
> of a structure that is allocated a lot.
sctp_outq is _embedded_ into an sctp_association structure, which
has [size: 2280, cachelines: 36, members: 76]! A next step would be
to try to reorder its elements carefully and see if we can reduce
the size by filling some holes.
next prev parent reply other threads:[~2013-04-17 9:26 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-04-16 21:07 [PATCH net-next 0/9] Minor SCTP cleanups all over the place Daniel Borkmann
2013-04-16 21:07 ` [PATCH net-next 1/9] net: sctp: sctp_ssnmap: remove 'malloced' element from struct Daniel Borkmann
2013-04-17 12:45 ` Neil Horman
2013-04-17 12:52 ` Daniel Borkmann
2013-04-17 17:17 ` Daniel Borkmann
2013-04-17 19:18 ` Neil Horman
2013-04-16 21:07 ` [PATCH net-next 2/9] net: sctp: sctp_inq: remove dead code Daniel Borkmann
2013-04-17 12:47 ` Neil Horman
2013-04-16 21:07 ` [PATCH net-next 3/9] net: sctp: sctp_outq: remove 'malloced' from its struct Daniel Borkmann
2013-04-17 12:57 ` Neil Horman
2013-04-16 21:07 ` [PATCH net-next 4/9] net: sctp: sctp_outq: consolidate chars into bitfield Daniel Borkmann
2013-04-17 8:43 ` David Laight
2013-04-17 9:26 ` Daniel Borkmann [this message]
2013-04-17 15:27 ` Neil Horman
2013-04-17 15:35 ` Vlad Yasevich
2013-04-17 15:40 ` Neil Horman
2013-04-17 15:38 ` Daniel Borkmann
2013-04-17 15:44 ` Vlad Yasevich
2013-04-17 15:31 ` Neil Horman
2013-04-16 21:07 ` [PATCH net-next 5/9] net: sctp: outqueue: simplify sctp_outq_uncork function Daniel Borkmann
2013-04-17 15:32 ` Neil Horman
2013-04-16 21:07 ` [PATCH net-next 6/9] net: sctp: sctp_transport: remove unused variable Daniel Borkmann
2013-04-17 15:34 ` Neil Horman
2013-04-16 21:07 ` [PATCH net-next 7/9] net: sctp: sctp_bind_addr: remove dead code Daniel Borkmann
2013-04-17 15:35 ` Neil Horman
2013-04-16 21:07 ` [PATCH net-next 8/9] net: sctp: sctp_ulpq: remove 'malloced' struct member Daniel Borkmann
2013-04-17 15:46 ` Neil Horman
2013-04-16 21:07 ` [PATCH net-next 9/9] net: sctp: sctp_ulpq: do not use char as a " Daniel Borkmann
2013-04-17 15:36 ` Vlad Yasevich
2013-04-17 15:41 ` Daniel Borkmann
2013-04-17 15:45 ` Neil Horman
2013-04-17 16:28 ` David Laight
2013-04-17 18:13 ` [PATCH net-next 0/9] Minor SCTP cleanups all over the place David Miller
2013-04-17 18:55 ` Daniel Borkmann
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