lkml.org 
[lkml]   [2004]   [Aug]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    SubjectRe: [patch] voluntary-preempt-2.6.8-rc3-O5
    From
    Date
    Lee Revell <rlrevell@joe-job.com> wrote:

    > On Wed, 2004-08-11 at 07:48, Linh Dang wrote:
    >> Hi,
    >>
    >> I'm not running the voluntary-preempt-* patches. but I do see some
    >> long latencies with:
    >>
    >> vanilla 2.6.7+preempt-timing+defer-softirq
    >>
    >> which were NOT reported here. Is it useful the report them?
    >>
    >
    > Probably not. Many latency issues as well as bugs in the preempt
    > timing patch have been fixed since then. You should try the latest
    > version.

    which "latest"? Linus's 2.6.8-rcX or Andrew's -mm's or Ingo's patches.

    I've looked at Ingo patches but didn't see fixes for the followings:

    1. In sys_mount(): do_mount() is called with the BKL held. on jffs2
    system, jffs2 might for a big media-scan and lock preemption for
    several msecs. even if jffs2_scan_eraseblock() calls cond_resched()
    for every flash sector, scanning one sector is still very long.

    2. netif_receive_skb(): the rcu_read_lock() is too broad. IMHO, it's
    only needed around the 2 list_for_each_entry_rcu()s. There's no
    reason why rcu_read_lock() is needed when calling ip_recv on the
    skb.

    3. with Ingo's patches, if all softirqs are done by the daemon then
    there's should be NO need to call local_bh_disable()/enable()
    around the processing loop in ___do_softirq().

    4. in cfi_cmdset_0002.c, using spin_lock_bh() to guard struct flchip
    seems to be an overkill. why a semaphore is NOT sufficient?


    I'm a total newbie so it's possible that I'm totally wrong about the
    aboves.


    Regards

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

    \
     
     \ /
      Last update: 2005-03-22 14:05    [W:5.264 / U:0.020 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site