lkml.org 
[lkml]   [2010]   [Dec]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [Patch 00/15] Reduce tracing payload size.
On Mon, Dec 6, 2010 at 3:58 PM, Andi Kleen <andi@firstfloor.org> wrote:
> On Mon, Dec 06, 2010 at 08:56:37AM -0500, Ted Ts'o wrote:
>> On Mon, Dec 06, 2010 at 02:22:00PM +0100, Andi Kleen wrote:
>> > David Sharp <dhsharp@google.com> writes:
>> > >
>> > > These patches are just a start to shrinking the size of trace events. I am
>> > > planning to also make small versions of trace events that are used when
>> > > CONFIG_SMALL_TRACES is enabled. I'm also open to discussion of other ways to
>> > > shrink event sizes.
>> >
>> > Maybe the simplest would be to lzo them as they get logged?
>> > I assume you already considered that?
>>
>> The tracing subsystem is supposed to be extremely low-overhead.
>> Compressiong the event log would add considerable CPU overhead.  If we
>
> lzo as a rule of thumb is about as expensive as 3x memcpy()
> That's not really expensive.

That is true for the decompression step but not for the compression
one, which takes more than 10 memcpys().

>
> -Andi
>
> --
> ak@linux.intel.com -- Speaking for myself only.
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at  http://www.tux.org/lkml/
>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2010-12-06 17:33    [W:0.068 / U:0.112 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site