archive mirror
 help / color / mirror / Atom feed
From: Thomas Gleixner <>
To: Nicolas Pitre <>
Cc: Daniel Lezcano <>,,,,,
Subject: Re: [PATCH V4] irq: Track the interrupt timings
Date: Tue, 14 Jun 2016 18:36:01 +0200 (CEST)	[thread overview]
Message-ID: <alpine.DEB.2.11.1606141833180.5839@nanos> (raw)
In-Reply-To: <alpine.LFD.2.20.1606141105320.1714@knanqh.ubzr>

On Tue, 14 Jun 2016, Nicolas Pitre wrote:
> On Tue, 14 Jun 2016, Daniel Lezcano wrote:
> > If the storage is a bit larger (let's say 16 values) and there is no memset
> > and the sum is not computed, at least we need a count for the number of values
> > in the array before this one is fulfilled, otherwise the statistics will be
> > wrong as we will take into account the entire array with old values, no ?
> The point is not to change from 8 to 16 entries, but to store raw 64-bit 
> timestamps instead of computed 32-bit deltas.  Whether or not those 
> timestamps are too far apart and discarded can be done at idle entry 
> time.

Correct, and you don't have to know how many timestamps are in the array
simply because if it is cleared at init time, then any not yet set value will
create a large gap, which you filter out.

The point is to make the fast path overhead as small as possible. And if
that's just a store and index increment, then it can be inline and not a
function call.



      parent reply	other threads:[~2016-06-14 16:38 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-04-13 11:05 Daniel Lezcano
2016-04-22 18:21 ` Daniel Lezcano
2016-05-03 13:44 ` Daniel Lezcano
2016-06-10 14:52 ` Thomas Gleixner
2016-06-10 15:11   ` Nicolas Pitre
2016-06-10 15:20     ` Thomas Gleixner
2016-06-10 15:29       ` Nicolas Pitre
2016-06-14 13:36   ` Daniel Lezcano
2016-06-14 15:10     ` Nicolas Pitre
2016-06-14 15:38       ` Daniel Lezcano
2016-06-14 16:36       ` Thomas Gleixner [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=alpine.DEB.2.11.1606141833180.5839@nanos \ \ \ \ \ \ \ \ \
    --subject='Re: [PATCH V4] irq: Track the interrupt timings' \

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).