Skip site navigation (1)Skip section navigation (2)
Date:      Tue, 16 Oct 2001 09:29:45 -0700 (PDT)
From:      Matthew Dillon <dillon@apollo.backplane.com>
To:        Dag-Erling Smorgrav <des@ofug.org>
Cc:        Bruce Evans <bde@zeta.org.au>, <cvs-committers@FreeBSD.ORG>, <cvs-all@FreeBSD.ORG>
Subject:   Re: cvs commit: src/sys/vm vnode_pager.c
Message-ID:  <200110161629.f9GGTju31481@apollo.backplane.com>

next in thread | raw e-mail | index | archive | help

:I did 'kgmon -rb ; sync ; sync ; sync ; kgmon -hpr'.  The results are
:attached.
:
:BTW, it should be possible to make profiling a normal kernel option
:(with a little help from 'makeoptions' like we do for debugging).
:It'd take a few changes to conf/{files,options} and the Makefile
:skeletons, but it would allow us to remove quite a bit of special-
:case code from config(8).
:
:DES
:-- 
:Dag-Erling Smorgrav - des@ofug.org

    Ugh.  This is -current.  All bets are off.

    In anycase, this profile output appears to indicate that your
    problem is not quota-related, but instead mutex related.

    ffs_sync() in -current is doing a lot of mutex operations
    in the loop.  If you have various -current mutex debugging
    options turned on, even the default ones I think, this could
    be responsible for the latency you are experiencing.  Each
    scan loop is doing four mutex ops.

						-Matt


:[1]     89.5   32.81        0.05 1046526+4696024 <cycle 1 as a whole>	[1]
:               32.31        0.03 1168605             _mtx_unlock_spin_flags <cycle 1> [2]
:
:[2]     88.0   32.31        0.03 1168605         _mtx_unlock_spin_flags <cycle 1> [2]
:                0.03        0.00 1168605/1720935     _mtx_assert [86]
:                                 1168605             witness_unlock <cycle 1> [37]

:[5]     79.3    0.00       29.14    3082         syscall [5]
:                0.00       26.60       3/3           sync [7]
:
:-----------------------------------------------
:
:                0.38       25.49      15/16          sync [7]
:[6]     75.1    0.41       27.19      16         ffs_sync [6]
:                0.09       13.52  429901/465440      _mtx_unlock_flags [8]
:                0.08       13.50  429904/465456      _mtx_lock_flags [9]
:
:-----------------------------------------------
:
:                0.00       26.60       3/3           syscall [5]
:[7]     72.4    0.00       26.60       3         sync [7]
:                0.38       25.49      15/16          ffs_sync [6]
:
:-----------------------------------------------
:[15]     4.8    0.00        1.76                 sched_sync [15]
:                0.00        1.75       1/1           sync_fsync [16]
:-----------------------------------------------
:
:                0.00        1.75       1/1           sched_sync [15]
:[16]     4.8    0.00        1.75       1         sync_fsync [16]
:                0.03        1.70       1/16          ffs_sync [6]
:                0.01        0.02       1/25          vfs_msync [17]
:
:-----------------------------------------------
:
:                0.01        0.02       1/25          sync_fsync [16]
:                0.17        0.55      24/25          sync [7]
:[17]     2.0    0.18        0.57      25         vfs_msync [17]
:                0.13        0.44  214914/219311      ufs_vnoperate <cycle 2> [39]
:                0.00        0.00      25/465440      _mtx_unlock_flags [8]
:                0.00        0.00      25/465456      _mtx_lock_flags [9]
:                0.00        0.00     141/219311      spec_vnoperate <cycle 2> [49]
:                0.00        0.00      18/219311      vop_defaultop <cycle 2> [68]
:                0.00        0.00       6/219311      ufs_vnoperatefifo <cycle 2> [340]
:                0.00        0.00      25/1720935     _mtx_assert [86]
:                0.00        0.00      25/26          vop_eopnotsupp [677]
:

To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe cvs-all" in the body of the message




Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?200110161629.f9GGTju31481>