• Andrew Morton's avatar
    [PATCH] remove PG_launder · a2536452
    Andrew Morton authored
    Removal of PG_launder.
    
    It's not obvious (to me) why this ever existed.  If it's to prevent
    deadlocks then I'd like to know who was performing __GFP_FS allocations
    while holding a page lock?
    
    But in 2.5, the only memory allocations which are performed when the
    caller holds PG_writeback against an unsubmitted page are those which
    occur inside submit_bh().  There will be no __GFS_FS allocations in
    that call chain.
    
    Removing PG_launder means that memory allocators can block on any
    PageWriteback() page at all, which reduces the risk of very long list
    walks inside pagemap_lru_lock in shrink_cache().
    a2536452
page-writeback.c 16.6 KB