public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Thomas Graf <tgraf@suug.ch>
To: Herbert Xu <herbert@gondor.apana.org.au>
Cc: David Miller <davem@davemloft.net>, Phil Sutter <phil@nwl.cc>,
	Eric Dumazet <eric.dumazet@gmail.com>,
	netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
	fengguang.wu@intel.com, wfg@linux.intel.com, lkp@01.org
Subject: Re: rhashtable: Use __vmalloc with GFP_ATOMIC for table allocation
Date: Wed, 9 Dec 2015 03:42:48 +0100	[thread overview]
Message-ID: <20151209024248.GA20213@pox.localdomain> (raw)
In-Reply-To: <20151209023844.GA24736@gondor.apana.org.au>

On 12/09/15 at 10:38am, Herbert Xu wrote:
> On Wed, Dec 09, 2015 at 03:36:32AM +0100, Thomas Graf wrote:
> > 
> > Without knowing your exact implementation plans: introducing an
> > additional reference indirection for every lookup will have a
> > huge performance penalty as well.
> > 
> > Is your plan to only introduce the master table after an
> > allocation has failed?
> 
> Right, obviously the extra indirections would only come into play
> after a failed allocation.  As soon as we can run the worker thread
> it'll try to remove the extra indirections by doing vmalloc.

OK, this sounds like a good compromise. The penalty is isolated
for the duration of the atomic burst.

  reply	other threads:[~2015-12-09  2:42 UTC|newest]

Thread overview: 39+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-11-20 17:17 [PATCH v2 0/4] improve fault-tolerance of rhashtable runtime-test Phil Sutter
2015-11-20 17:17 ` [PATCH v2 1/4] rhashtable-test: add cond_resched() to thread test Phil Sutter
2015-11-20 17:17 ` [PATCH v2 2/4] rhashtable-test: retry insert operations Phil Sutter
2015-11-20 17:17 ` [PATCH v2 3/4] rhashtable-test: calculate max_entries value by default Phil Sutter
2015-11-20 17:17 ` [PATCH v2 4/4] rhashtable-test: allow to retry even if -ENOMEM was returned Phil Sutter
2015-11-20 17:28   ` Phil Sutter
2015-11-23 17:38 ` [PATCH v2 0/4] improve fault-tolerance of rhashtable runtime-test David Miller
2015-11-30  9:37 ` Herbert Xu
2015-11-30 10:14   ` Phil Sutter
2015-11-30 10:18     ` Herbert Xu
2015-12-03 12:41       ` rhashtable: Prevent spurious EBUSY errors on insertion Herbert Xu
2015-12-03 15:38         ` Phil Sutter
2015-12-04 19:38         ` David Miller
2015-12-17  8:46         ` Xin Long
2015-12-17  8:48           ` Herbert Xu
2015-12-17  9:00             ` Xin Long
2015-12-17 16:07               ` Xin Long
2015-12-18  2:26                 ` Herbert Xu
2015-12-18  8:18                   ` Xin Long
2015-12-17 17:00               ` David Miller
2015-12-03 12:51       ` rhashtable: ENOMEM errors when hit with a flood of insertions Herbert Xu
2015-12-03 15:08         ` David Laight
2015-12-03 16:08         ` Eric Dumazet
2015-12-04  0:07           ` Herbert Xu
2015-12-04 14:39           ` rhashtable: Use __vmalloc with GFP_ATOMIC for table allocation Herbert Xu
2015-12-04 17:01             ` Phil Sutter
2015-12-04 17:45               ` Eric Dumazet
2015-12-04 18:15                 ` Phil Sutter
2015-12-05  7:06                   ` Herbert Xu
2015-12-07 15:35                     ` Thomas Graf
2015-12-07 19:29                       ` David Miller
2015-12-09  2:18                     ` Thomas Graf
2015-12-09  2:24                       ` Herbert Xu
2015-12-09  2:36                         ` Thomas Graf
2015-12-09  2:38                           ` Herbert Xu
2015-12-09  2:42                             ` Thomas Graf [this message]
2015-12-04 21:53             ` David Miller
2015-12-05  7:03               ` Herbert Xu
2015-12-06  3:48                 ` David Miller

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=20151209024248.GA20213@pox.localdomain \
    --to=tgraf@suug.ch \
    --cc=davem@davemloft.net \
    --cc=eric.dumazet@gmail.com \
    --cc=fengguang.wu@intel.com \
    --cc=herbert@gondor.apana.org.au \
    --cc=linux-kernel@vger.kernel.org \
    --cc=lkp@01.org \
    --cc=netdev@vger.kernel.org \
    --cc=phil@nwl.cc \
    --cc=wfg@linux.intel.com \
    /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