lkml.org 
[lkml]   [2005]   [Dec]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    SubjectRe: [RFC][PATCH 0/3] TCP/IP Critical socket communication mechanism
    From
    Date
    On Thu, 2005-12-15 at 00:21 -0800, David S. Miller wrote:
    > From: Sridhar Samudrala <sri@us.ibm.com>
    > Date: Wed, 14 Dec 2005 23:37:37 -0800 (PST)
    >
    > > Instead, you seem to be suggesting in_emergency to be set dynamically
    > > when we are about to run out of ATOMIC memory. Is this right?
    >
    > Not when we run out, but rather when we reach some low water mark, the
    > "critical sockets" would still use GFP_ATOMIC memory but only
    > "critical sockets" would be allowed to do so.
    >
    > But even this has faults, consider the IPSEC scenerio I mentioned, and
    > this applies to any kind of encapsulation actually, even simple
    > tunneling examples can be concocted which make the "critical socket"
    > idea fail.
    >
    > The knee jerk reaction is "mark IPSEC's sockets critical, and mark the
    > tunneling allocations critical, and... and..." well you have
    > GFP_ATOMIC then my friend.
    >
    > In short, these "seperate page pool" and "critical socket" ideas do
    > not work and we need a different solution, I'm sorry folks spent so
    > much time on them, but they are heavily flawed.

    maybe it should be approached from the other side; having a way to mark
    connections as low priority (say incoming http connections to your
    webserver) or as non-critical/expendable would give the "normal"
    GFP_ATOMIC ones a better chance in case of overload/DDOS etc. It's not
    going to solve the VM deadlock issue wrt iscsi/nfs; however it might be
    useful in the "survive slashdot" sense...

    -
    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: 2005-12-15 09:38    [W:0.039 / U:29.916 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site