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    Subjecttest9-pre6 and GFP_BUFFER allocations

    What will happen in this scenario:
    a process
    * grabs a fs semaphore
    * needs some buffers to do IO, calls __alloc_pages(GFP_BUFFER)
    Suppose the system is MIN on free mem, has no inactive_clean pages.
    We will end up around line 446 in pages_alloc.c and issue a
    try_to_free_pages(...). Then goto try_again.
    * In our case this is unlikely to work - not allowed to do IO.
    * Will we sleep? Probably not, not even in refill_inactive (no GFP_IO)
    BTW, Why can't we schedule if GFP_IO is not set???
    * Will we free any page, to get above MIN - only if there are enough
    clean pages in active list.
    * Won't we end up in an infinite loop?
    Suppose it does sleep. Will kswapd then be able to free any page
    assuming we are holding a critical fs semaphore...

    Or am I missing something, again?

    One approach could be: only goto try_again if GFP_IO is set.
    And alloc one page from the critical memory pool.
    I will try this.


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