qemu-devel.nongnu.org archive mirror
 help / color / mirror / Atom feed
From: Peter Xu <peterx@redhat.com>
To: Kunkun Jiang <jiangkunkun@huawei.com>
Cc: "Juan Quintela" <quintela@redhat.com>,
	"David Edmondson" <dme@dme.org>,
	"Dr . David Alan Gilbert" <dgilbert@redhat.com>,
	"open list:All patches CC here" <qemu-devel@nongnu.org>,
	"Cédric Le Goater" <clg@kaod.org>,
	"Alexey Romko" <nevilad@yahoo.com>,
	"Zenghui Yu" <yuzenghui@huawei.com>,
	wanghaibin.wang@huawei.com, "Keqian Zhu" <zhukeqian1@huawei.com>,
	"Andrey Gruzdev" <andrey.gruzdev@virtuozzo.com>
Subject: Re: [PATCH v4 1/2] migration/ram: Reduce unnecessary rate limiting
Date: Tue, 16 Mar 2021 17:39:06 -0400	[thread overview]
Message-ID: <20210316213906.GF395976@xz-x1> (raw)
In-Reply-To: <20210316125716.1243-2-jiangkunkun@huawei.com>

On Tue, Mar 16, 2021 at 08:57:15PM +0800, Kunkun Jiang wrote:
> When the host page is a huge page and something is sent in the
> current iteration, migration_rate_limit() should be executed.
> If not, it can be omitted.
> 
> Signed-off-by: Keqian Zhu <zhukeqian1@huawei.com>
> Signed-off-by: Kunkun Jiang <jiangkunkun@huawei.com>
> Reviewed-by: David Edmondson <david.edmondson@oracle.com>
> ---
>  migration/ram.c | 9 +++++++--
>  1 file changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/migration/ram.c b/migration/ram.c
> index 72143da0ac..3eb5b0d7a7 100644
> --- a/migration/ram.c
> +++ b/migration/ram.c
> @@ -2015,8 +2015,13 @@ static int ram_save_host_page(RAMState *rs, PageSearchStatus *pss,
>  
>          pages += tmppages;
>          pss->page++;
> -        /* Allow rate limiting to happen in the middle of huge pages */
> -        migration_rate_limit();
> +        /*
> +         * Allow rate limiting to happen in the middle of huge pages if
> +         * something is sent in the current iteration.
> +         */
> +        if (pagesize_bits > 1 && tmppages > 0) {
> +            migration_rate_limit();
> +        }

Sorry I'm still not a fan of this - I'd even prefer calling that once more just
to make sure it won't be forgotten to be called..  Not to say it's merely a noop.

I'll leave this to Dave..  Maybe I'm too harsh! :)

-- 
Peter Xu



  reply	other threads:[~2021-03-16 21:50 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-16 12:57 [PATCH v4 0/2] Some modification about ram_save_host_page() Kunkun Jiang
2021-03-16 12:57 ` [PATCH v4 1/2] migration/ram: Reduce unnecessary rate limiting Kunkun Jiang
2021-03-16 21:39   ` Peter Xu [this message]
2021-03-17  1:37     ` Kunkun Jiang
2021-03-17 10:43       ` David Edmondson
2021-03-17 12:05       ` Dr. David Alan Gilbert
2021-03-16 12:57 ` [PATCH v4 2/2] migration/ram: Optimize ram_save_host_page() Kunkun Jiang
2021-03-16 21:39   ` Peter Xu
2021-04-06 13:19 ` [PATCH v4 0/2] Some modification about ram_save_host_page() Kunkun Jiang
2021-04-06 17:14   ` Dr. David Alan Gilbert
2021-04-07  9:32     ` Kunkun Jiang
2021-05-11  9:17 ` Dr. David Alan Gilbert

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=20210316213906.GF395976@xz-x1 \
    --to=peterx@redhat.com \
    --cc=andrey.gruzdev@virtuozzo.com \
    --cc=clg@kaod.org \
    --cc=dgilbert@redhat.com \
    --cc=dme@dme.org \
    --cc=jiangkunkun@huawei.com \
    --cc=nevilad@yahoo.com \
    --cc=qemu-devel@nongnu.org \
    --cc=quintela@redhat.com \
    --cc=wanghaibin.wang@huawei.com \
    --cc=yuzenghui@huawei.com \
    --cc=zhukeqian1@huawei.com \
    --subject='Re: [PATCH v4 1/2] migration/ram: Reduce unnecessary rate limiting' \
    /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

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).