public inbox for kvm@vger.kernel.org
 help / color / mirror / Atom feed
From: "Radim Krčmář" <rkrcmar@redhat.com>
To: Igor Mammedov <imammedo@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>,
	linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
	yoshikawa_takuya_b1@lab.ntt.co.jp
Subject: Re: [PATCH 1/3] kvm: memslots: track id_to_index changes during the insertion sort
Date: Fri, 14 Nov 2014 15:41:36 +0100	[thread overview]
Message-ID: <20141114144135.GC27697@potion.brq.redhat.com> (raw)
In-Reply-To: <20141114151725.55774165@igors-macbook-pro.local>

2014-11-14 15:17+0100, Igor Mammedov:
> > (We'll have to change it into an interval tree, or something, if the
> >  number of slots rises anyway.)
> Only if it rises to huge amount, I've played with proposed 512 memslots
> and it takes ~10000 cycles which is 5% of current heapsort overhead.
> Taking in account that it's slow path anyway, it's unlikely that there
> would be need to speedup this case even more.

Yes, your improvement is great and would work even for higher amounts.

I meant that our lookup is currently pretty sad -- O(N) that is
presumably optimized by looking at the largest regions first.

Maybe we would benefit from O(log N) lookup even with 128 memslots.

  reply	other threads:[~2014-11-14 14:41 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-11-14 11:11 [PATCH 0/3] KVM: simplification to the memslots code Paolo Bonzini
2014-11-14 11:12 ` [PATCH 1/3] kvm: memslots: track id_to_index changes during the insertion sort Paolo Bonzini
2014-11-14 13:34   ` Igor Mammedov
2014-11-14 13:35   ` Radim Krčmář
2014-11-14 14:17     ` Igor Mammedov
2014-11-14 14:41       ` Radim Krčmář [this message]
2014-11-14 14:44         ` Paolo Bonzini
2014-11-14 14:29     ` Paolo Bonzini
2014-11-14 14:44       ` Radim Krčmář
2014-11-14 11:12 ` [PATCH 2/3] kvm: commonize allocation of the new memory slots Paolo Bonzini
2014-11-14 14:21   ` Igor Mammedov
2014-11-17  1:49   ` Takuya Yoshikawa
2014-11-14 11:12 ` [PATCH 3/3] kvm: simplify update_memslots invocation Paolo Bonzini
2014-11-14 14:24   ` Igor Mammedov
2014-11-17  1:56 ` [PATCH 0/3] KVM: simplification to the memslots code Takuya Yoshikawa
2014-11-17  9:23   ` Paolo Bonzini
2014-11-17  9:30     ` Takuya Yoshikawa

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:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

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

  git send-email \
    --in-reply-to=20141114144135.GC27697@potion.brq.redhat.com \
    --to=rkrcmar@redhat.com \
    --cc=imammedo@redhat.com \
    --cc=kvm@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=pbonzini@redhat.com \
    --cc=yoshikawa_takuya_b1@lab.ntt.co.jp \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox