The second maintenance release of the 11th version of the reverse
mapping based VM is now available.
This is an attempt at making a more robust and flexible VM
subsystem, while cleaning up a lot of code at the same time.
The patch is available from:
http://surriel.com/patches/2.4/2.4.17-rmap-11b
and http://linuxvm.bkbits.net/
My big TODO items for a next release are:
- fix page_launder() so it doesn't submit the whole
inactive_dirty list for writeout in one go
rmap 11b:
- added low latency reschedule points in vmscan.c (me)
- make i810_dma.c include mm_inline.h too (William Lee Irwin)
- wake up kswapd sleeper tasks on OOM kill so the
killed task can continue on its way out (me)
- tune page allocation sleep point a little (me)
rmap 11a:
- don't let refill_inactive() progress count for OOM (me)
- after an OOM kill, wait 5 seconds for the next kill (me)
- agpgart_be fix for hashed waitqueues (William Lee Irwin)
rmap 11:
- fix stupid logic inversion bug in wakeup_kswapd() (Andrew Morton)
- fix it again in the morning (me)
- add #ifdef BROKEN_PPC_PTE_ALLOC_ONE to rmap.h, it
seems PPC calls pte_alloc() before mem_map[] init (me)
- disable the debugging code in rmap.c ... the code
is working and people are running benchmarks (me)
- let the slab cache shrink functions return a value
to help prevent early OOM killing (Ed Tomlinson)
- also, don't call the OOM code if we have enough
free pages (me)
- move the call to lru_cache_del into __free_pages_ok (Ben LaHaise)
- replace the per-page waitqueue with a hashed
waitqueue, reduces size of struct page from 64
bytes to 52 bytes (48 bytes on non-highmem machines) (William Lee Irwin)
rmap 10:
- fix the livelock for real (yeah right), turned out
to be a stupid bug in page_launder_zone() (me)
- to make sure the VM subsystem doesn't monopolise
the CPU, let kswapd and some apps sleep a bit under
heavy stress situations (me)
- let __GFP_HIGH allocations dig a little bit deeper
into the free page pool, the SCSI layer seems fragile (me)
rmap 9:
- improve comments all over the place (Michael Cohen)
- don't panic if page_remove_rmap() cannot find the
rmap in question, it's possible that the memory was
PG_reserved and belonging to a driver, but the driver
exited and cleared the PG_reserved bit (me)
- fix the VM livelock by replacing > by >= in a few
critical places in the pageout code (me)
- treat the reclaiming of an inactive_clean page like
allocating a new page, calling try_to_free_pages()
and/or fixup_freespace() if required (me)
- when low on memory, don't make things worse by
doing swapin_readahead (me)
rmap 8:
- add ANY_ZONE to the balancing functions to improve
kswapd's balancing a bit (me)
- regularize some of the maximum loop bounds in
vmscan.c for cosmetic purposes (William Lee Irwin)
- move page_address() to architecture-independent
code, now the removal of page->virtual is portable (William Lee Irwin)
- speed up free_area_init_core() by doing a single
pass over the pages and not using atomic ops (William Lee Irwin)
- documented the buddy allocator in page_alloc.c (William Lee Irwin)
rmap 7:
- clean up and document vmscan.c (me)
- reduce size of page struct, part one (William Lee Irwin)
- add rmap.h for other archs (untested, not for ARM) (me)
rmap 6:
- make the active and inactive_dirty list per zone,
this is finally possible because we can free pages
based on their physical address (William Lee Irwin)
- cleaned up William's code a bit (me)
- turn some defines into inlines and move those to
mm_inline.h (the includes are a mess ...) (me)
- improve the VM balancing a bit (me)
- add back inactive_target to /proc/meminfo (me)
rmap 5:
- fixed recursive buglet, introduced by directly
editing the patch for making rmap 4 ;))) (me)
rmap 4:
- look at the referenced bits in page tables (me)
rmap 3:
- forgot one FASTCALL definition (me)
rmap 2:
- teach try_to_unmap_one() about mremap() (me)
- don't assign swap space to pages with buffers (me)
- make the rmap.c functions FASTCALL / inline (me)
rmap 1:
- fix the swap leak in rmap 0 (Dave McCracken)
rmap 0:
- port of reverse mapping VM to 2.4.16 (me)
Rik
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