From: Theodore Ts'o <tytso@mit.edu>
To: Anatol Pomozov <anatol.pomozov@gmail.com>
Cc: adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org
Subject: Re: [PATCH 1/2] ext4: Realign trace events structs to make it smaller
Date: Sun, 12 Aug 2012 22:29:44 -0400 [thread overview]
Message-ID: <20120813022944.GC13080@thunk.org> (raw)
In-Reply-To: <1342631254-23891-1-git-send-email-anatol.pomozov@gmail.com>
On Wed, Jul 18, 2012 at 10:07:33AM -0700, Anatol Pomozov wrote:
> Most hardware architectures require that data (including struct fields)
> have to be aligned in memory. To make it happen compiler inserts padding
> between struct fields if they are not aligned correctly.
>
> Reorder fields to remove paddings and make structures denser. Making data
> smaller saves some memory that is very important for trace events.
> Tracing buffer has limited size and making objects smaller we can put more
> of them without overflowing the tracing buffer.
>
> To find data struct holes I used 'pahole -H 1 -E -I vmlinux.o' from
> 'dwarves' package.
>
> Signed-off-by: Anatol Pomozov <anatol.pomozov@gmail.com>
Thanks, applied.
- Ted
prev parent reply other threads:[~2012-08-13 2:29 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-07-18 17:07 [PATCH 1/2] ext4: Realign trace events structs to make it smaller Anatol Pomozov
2012-07-18 17:07 ` [PATCH 2/2] ext4: Add missing space to trace message Anatol Pomozov
2012-08-13 2:29 ` Theodore Ts'o
2012-08-13 2:29 ` Theodore Ts'o [this message]
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