lkml.org 
[lkml]   [2005]   [Mar]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [ANNOUNCE 0/6] Open-iSCSI High-Performance Initiator for Linux
    On Tue, Mar 08, 2005 at 10:25:58PM -0800, Dmitry Yusupov wrote:
    > On Tue, 2005-03-08 at 22:05 -0800, Matt Mackall wrote:
    > > On Tue, Mar 08, 2005 at 09:51:39PM -0800, Alex Aizman wrote:
    > > > Matt Mackall wrote:
    > > >
    > > > >How big is the userspace client?
    > > > >
    > > > Hmm.. x86 executable? source?
    > > >
    > > > Anyway, there's about 12,000 lines of user space code, and growing. In
    > > > the kernel we have approx. 3,300 lines.
    > > >
    > > > >>- 450MB/sec Read on a single connection (2-way 2.4Ghz Opteron, 64KB block
    > > > >>size);
    > > > >
    > > > >With what network hardware and drives, please?
    > > > >
    > > > Neterion's 10GbE adapters. RAM disk on the target side.
    > >
    > > Ahh.
    > >
    > > Snipped my question about userspace deadlocks - that was the important
    > > one. It is in fact why the sfnet one is written as it is - it
    > > originally had a userspace component and turned out to be easy to
    > > deadlock under load because of it.
    >
    > As Scott Ferris pointed out, the main reason for deadlock in sfnet was
    > blocking behavior of page cache when daemon tried to do filesystem IO,
    > namely syslog().

    That was just one of several problems. And ISTR deciding that
    particular one was quite nasty when we first encountered it though I
    no longer remember the details.

    > That was 2.4.x kernel. We don't know whether it is
    > fixed in 2.6.x. If someone knows, please let us know. Meanwhile we came
    > up with work-around design in user-space. "Paged out" problem fixed
    > already in our subversion repository by utilizing mlockall()
    > syscall.

    I presume this is dynamically linked against glibc?

    > Also we have IMHO, working solution for OOM during ERL=0 TCP re-connect.

    Care to describe it?

    --
    Mathematics is the supreme nostalgia of our time.
    -
    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 14:11    [W:0.026 / U:31.220 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site