spin lock contention: lru_list lock

From: Manfred Spraul (manfreds@colorfullife.com)
Date: Sat Feb 19 2000 - 07:53:14 EST

  • Next message: Khimenko Victor: "Re: Of removable devices"

    I tried sgi's lockmeter with 2.3.46, and during a simple

            make -j4 dep

    I get extremely long hold times for the lru_list lock:

    sync_buffers(): up to 14 milliseconds, average 12 milliseconds. [called
    10 times per second.]
    __invalidate_buffers(): up to 8 milliseconds, average 7 milliseconds.[
    called ~4.5 times/sec]

    I assume that everything is cached:
    * 192 MB memory.
    * /proc/meminfo: Cached 122 MB
    * slabinfo: dentry_cache: 17705 entries, inode cache 15174 entries,
    buffer heads: 108189 entries.

    Is it possible to optimize sync_buffers()/__invalidate_buffers()
    further? I assume that with 1 GB memory, the hold times could become a
    problem for a huge fileserver. 

    --
	Manfred
P.S.: some good news: except do_close [up to 34 milliseconds], noone
else owns a spinlock for more than 3 milliseconds.

    -
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu
Please read the FAQ at http://www.tux.org/lkml/

    This archive was generated by hypermail 2b29 : Sat Feb 19 2000 - 08:44:37 EST