lkml.org 
[lkml]   [2004]   [Jun]   [2]   [last100]   RSS Feed
Views: [more markup]  [less markup]  [headers]  [forward] 
 
Messages in this thread
/
DateWed, 02 Jun 2004 10:22:33 +0200
From"Ihar 'Philips' Filipau" <>
Subjecte1000 question
[ If this is wrong ML, will appreciate pointer to correct one. ]
[ CC: me, please - I'm not sub'd. ]
[ Intel's driver as in 2.6.5 - 
http://lxr.linux.no/source/drivers/net/e1000/e1000_main.c?v=2.6.5 ]

    I'm looking into e1000 driver in irq handling and what I see, 
puzzles me.

    Functions e1000_clean_{t,r}x_irq are very similar: both of them are 
checking descriptor flag updated by nic.
    Host CPU, obviously, to perform this check, will cache descriptor.
    If, say e1000_clean_rx_irq() will be called twice in short time 
range, I expect that it can miss change of the flag, since old flag may 
still sit in host CPU cache.
    Am I missing something here?

-- 
     Johnson's law:
            Systems resemble the organizations that create them.
--                              ___      ___
Ihar 'Philips' Filipau             \    /     Sr. Software Developer
Tel:    +49 681 959 16 0            \  /                 GIGA STREAM
Fax:    +49 681 959 16 100           \/        Konrad Zuse Strasse 7
Mobile: +49 173 39 462 49            /\           66115 Saarbruecken
email:  ifilipau@giga-stream.de     /  \                     Germany
www: http://www.giga-stream.de  ___/    \___   Switching for success

[unhandled content-type:application/x-pkcs7-signature]
\
 
 \ /
  Last update: 2005-03-22 14:03    [from the cache]
©2003-2008