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From: Haakon Riiser <hakonrk@ulrik.uio.no>
To: linux-kernel@vger.kernel.org
Subject: Re: Busy-wait delay in qmail 1.03 after upgrading to Linux 2.6
Date: Wed, 14 Jan 2004 01:07:46 +0100	[thread overview]
Message-ID: <20040114000746.GA691@s.chello.no> (raw)
In-Reply-To: <20040113154348.5542cb7b.akpm@osdl.org>

[Andrew Morton]

> OK, that's inconclusive.  Could you do a few runs, or leave it a day or
> two, wait until the problem is really prominent and see if you can gather a
> clearer profile?  The profiling overhead is negligible when profiling is
> enabled but not in use, so there is no need to reboot.

I tried running the test over and over, and after around 20 times,
it suddenly jumped from 0.3 seconds to 1.6 again.  Results follow:

strace:

  678   01:04:16.722816 write(5, "\0", 1) = 1 <1.635007>

time:

  real    0m1.666s
  user    0m0.008s
  sys     0m0.005s

prof.time:

  c0139ea0 buffered_rmqueue                              9   0.0256
  c0141e10 page_address                                  9   0.0469
  c0151a70 get_unused_fd                                 9   0.0216
  c0161830 open_namei                                    9   0.0089
  c01f8500 bin_search_in_dir_item                        9   0.0511
  c0144040 do_anonymous_page                            10   0.0189
  c0146300 find_vma                                     10   0.1042
  c013d650 kmem_cache_free                              11   0.1375
  c0145ab0 do_mmap_pgoff                                11   0.0061
  c0153640 __fput                                       11   0.0382
  c0161180 path_lookup                                  11   0.0362
  c01654f0 __pollwait                                   11   0.0529
  c022bec0 memcpy                                       11   0.1146
  c011aad0 add_wait_queue                               12   0.1250
  c0151860 dentry_open                                  12   0.0227
  c01539b0 __constant_c_and_count_memset                12   0.0833
  c0151d50 filp_close                                   13   0.0903
  c01f85b0 search_by_entry_key                          13   0.0262
  c01457c0 vma_merge                                    14   0.0186
  c02112a0 is_tree_node                                 14   0.1250
  c0142a20 zap_pte_range                                15   0.0347
  c022c650 __copy_from_user_ll                          15   0.0852
  c015f640 pipe_poll                                    16   0.1250
  c01655c0 max_select_fd                                16   0.0714
  c0117440 do_page_fault                                17   0.0131
  c0106d30 default_idle                                 19   0.3958
  c013d6a0 kfree                                        20   0.1786
  c0153760 fget                                         21   0.3281
  c01606a0 link_path_walk                               21   0.0091
  c022c5d0 __copy_to_user_ll                            22   0.1719
  c0211030 is_leaf                                      23   0.0496
  c016aaa0 __d_lookup                                   28   0.0833
  c0203d70 reiserfs_readdir                             28   0.0184
  c0155230 __find_get_block                             36   0.1607
  c01656a0 do_select                                    47   0.0653
  c01659a0 sys_select                                   50   0.0391
  c0211310 search_by_key                                90   0.0247
  c0109174 system_call                                 107   2.4318
  c022c0b0 fast_clear_page                             119   1.2396
  00000000 total                                      1251   0.0005

-- 
 Haakon

  reply	other threads:[~2004-01-14  0:09 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2004-01-13 21:09 Busy-wait delay in qmail 1.03 after upgrading to Linux 2.6 Haakon Riiser
2004-01-13 21:51 ` Andrew Morton
2004-01-13 23:26   ` Haakon Riiser
2004-01-13 23:43     ` Andrew Morton
2004-01-14  0:07       ` Haakon Riiser [this message]
2004-01-14 11:29         ` Haakon Riiser
2004-01-20  0:46           ` Haakon Riiser
2004-01-13 23:46     ` Haakon Riiser
2004-01-14  0:06       ` Andrew Morton
2004-01-14 10:27       ` Giuliano Pochini
2004-01-14 11:20         ` Haakon Riiser
2004-01-15  0:12         ` Haakon Riiser
  -- strict thread matches above, loose matches on Subject: below --
2004-01-20  5:51 Peter Maas
     [not found] <20040120021353.39e9155e.akpm@osdl.org>
2004-01-20 18:33 ` Fw: " Manfred Spraul
2004-01-20 19:22   ` Haakon Riiser
2004-01-20 19:45     ` Mike Fedyk

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