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From: erik quanstrom <quanstro@quanstro.net>
To: drivers@0xabadba.be, 9fans@9fans.net
Subject: Re: [9fans] "Blocks" in C
Date: Thu,  3 Sep 2009 21:52:07 -0400	[thread overview]
Message-ID: <93cb4c7c46cd98af895c531e743e7bb3@quanstro.net> (raw)
In-Reply-To: <182803949-1252028217-cardhu_decombobulator_blackberry.rim.net-863554438-@bda790.bisx.prod.on.blackberry>

On Thu Sep  3 21:38:30 EDT 2009, drivers@0xabadba.be wrote:
> To ensure only one thread in the kernel at a time?

yes.  http://en.wikipedia.org/wiki/Giant_lock
it allows only one kernel thread to run at a time.

the pool lock allows as many threads to run as
one would like, but they can't allocate concurrently
since blocks and kernel buffers are allocated through
the pool library.  this effectively ties kernel procs doing
io together by their shoelaces.  it's a big reason that a
number of ethernet drivers have private frame pools.

cutting the lock (any lock) out of the mix when shuffling
very small blocks around the kernel was worth double
the blocks/s in some tests i did.  sorry to be vague.  i
don't have a good writeup.

- erik



  reply	other threads:[~2009-09-04  1:52 UTC|newest]

Thread overview: 117+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-09-04  1:35 drivers
2009-09-04  1:52 ` erik quanstrom [this message]
  -- strict thread matches above, loose matches on Subject: below --
2009-09-18 15:50 drivers
2009-09-18 15:56 ` erik quanstrom
2009-09-17  9:19 Andrew Simmons
2009-09-17 14:45 ` LiteStar numnums
2009-09-17 17:24 ` Daniel Lyons
2009-09-02  8:04 Anant Narayanan
2009-09-02  9:43 ` Francisco J Ballesteros
2009-09-02 11:00   ` Philippe Anel
2009-09-02 11:13   ` Charles Forsyth
2009-09-03  9:52   ` Greg Comeau
2009-09-02 11:40 ` Eris Discordia
2009-09-02 12:32 ` Uriel
2009-09-02 14:20   ` Devon H. O'Dell
2009-09-03  9:52     ` Greg Comeau
2009-09-03 10:48       ` Akshat Kumar
2009-09-03 11:25         ` Charles Forsyth
2009-09-03 13:59         ` Greg Comeau
2009-09-03 15:15     ` Uriel
2009-09-03 15:44       ` David Leimbach
2009-09-03 16:01         ` Roman V Shaposhnik
2009-09-04  9:15           ` Greg Comeau
2009-09-04 16:49             ` Roman Shaposhnik
2009-09-03 16:02         ` erik quanstrom
2009-09-03 18:56           ` David Leimbach
2009-09-03 18:58             ` erik quanstrom
2009-09-03 19:13               ` David Leimbach
2009-09-03 19:36                 ` erik quanstrom
2009-09-03 19:50                   ` David Leimbach
2009-09-03 20:30                     ` Iruata Souza
2009-09-06 22:35                     ` Uriel
2009-09-07  0:41                       ` David Leimbach
2009-09-03 21:08                   ` Roman V Shaposhnik
2009-09-03 21:35                     ` erik quanstrom
2009-09-03 21:45                       ` David Leimbach
2009-09-03 21:49                         ` David Leimbach
2009-09-03 21:51                           ` David Leimbach
2009-09-03 22:36                       ` Roman V Shaposhnik
2009-09-04  9:16               ` Greg Comeau
2009-09-03 22:10           ` Daniel Lyons
2009-09-03 22:07         ` Daniel Lyons
2009-09-04  9:15         ` Greg Comeau
2009-09-04  3:21       ` Anant Narayanan
2009-09-04  3:52         ` erik quanstrom
2009-09-04  4:18           ` David Leimbach
2009-09-04  4:44             ` erik quanstrom
2009-09-04  5:31               ` David Leimbach
2009-09-04  5:35                 ` David Leimbach
2009-09-04  7:11                   ` Bakul Shah
2009-09-04  7:47                     ` David Leimbach
2009-09-04 14:41                       ` Bakul Shah
2009-09-04 15:04                         ` David Leimbach
2009-09-04 15:58                           ` Bakul Shah
2009-09-04 12:14                     ` erik quanstrom
2009-09-04 13:52                       ` David Leimbach
2009-09-04 13:59                         ` matt
2009-09-04 14:20                         ` erik quanstrom
2009-09-04 14:56                           ` David Leimbach
2009-09-06 23:03                             ` Uriel
2009-09-07  0:45                               ` David Leimbach
2009-09-04 16:50                       ` Roman Shaposhnik
2009-09-04  6:45               ` Bakul Shah
2009-09-04 16:44           ` Roman Shaposhnik
2009-09-04 16:58             ` Iruata Souza
2009-09-04 17:09               ` Roman Shaposhnik
2009-09-04 17:42             ` erik quanstrom
2009-09-04 18:34               ` erik quanstrom
2009-09-04 21:54               ` Roman V Shaposhnik
2009-09-07  9:06             ` Greg Comeau
2009-09-07  9:05         ` Greg Comeau
2009-09-07  9:40           ` Uriel
2009-09-08 15:31             ` David Leimbach
2009-09-08 15:44               ` Uriel
2009-09-08 16:40               ` Bakul Shah
2009-09-11 18:15                 ` Iruata Souza
2009-09-11 18:46                   ` David Leimbach
2009-09-11 20:36                   ` Roman V Shaposhnik
2009-09-11 21:28                     ` David Leimbach
2009-09-14 16:07                       ` Lawrence E. Bakst
2009-09-12 11:08                     ` Anant Narayanan
2009-09-13 19:03                       ` David Leimbach
2009-09-17  1:54                         ` Lawrence E. Bakst
2009-09-17  8:43                           ` Charles Forsyth
2009-09-17  9:12                             ` Daniel Lyons
2009-09-17 15:56                             ` David Leimbach
2009-09-17 17:38                               ` Jack Norton
2009-09-17 20:23                                 ` Anant Narayanan
2009-09-17 20:26                                   ` erik quanstrom
2009-09-17 20:31                                     ` Anant Narayanan
2009-09-17 20:47                                       ` Akshat Kumar
2009-09-17 21:02                                         ` erik quanstrom
2009-09-17 22:26                                           ` Steve Simon
2009-09-17 22:32                                           ` Roman V Shaposhnik
2009-09-18  2:05                                             ` Daniel Lyons
2009-09-18  9:30                                             ` Charles Forsyth
2009-09-18 11:41                                               ` erik quanstrom
2009-09-17 21:03                                       ` Uriel
2009-09-03  9:52   ` Greg Comeau
2009-09-02 14:08 ` Rodolfo (kix)
2009-09-03  9:52   ` Greg Comeau
     [not found] ` <C56117D7BD9A097270529AAE@192.168.1.2>
2009-09-02 15:07   ` David Leimbach
2009-09-02 15:26     ` Roman V Shaposhnik
2009-09-02 15:45       ` David Leimbach
2009-09-03 15:32     ` Uriel
2009-09-03 15:49       ` Roman V Shaposhnik
2009-09-03 15:54         ` erik quanstrom
2009-09-03 16:20           ` Roman V Shaposhnik
2009-09-03 16:44             ` erik quanstrom
2009-09-04  1:05               ` Roman V Shaposhnik
2009-09-04  1:30               ` Russ Cox
2009-09-04  1:32                 ` erik quanstrom
2009-09-03 21:54             ` James Tomaschke
2009-09-06 22:26           ` Uriel
2009-09-04  9:04       ` Greg Comeau
2009-09-02 15:20 ` Roman V Shaposhnik
2009-09-02 17:51   ` Bakul Shah

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