As usual, available from:
ftp://ftp.kernel.org/pub/linux/kernel/people/wli/kernels/2.5.74/2.5.74-wli-1.bz2
Various tidbits of new material. As usual, obscene amounts of NIH'ing.
I won't claim it's bug-free, but I will claim some modicum of speed.
Insert something humorous here about sharp, bleeding edges cutting the
unwary. The vfs locking changes here are in need of various kinds of
shaking down, stress testing, and review beyond what I've done thus far.
All 36 patches:
cpumask_t
Extended cpu bitmaps for NR_CPUS > BITS_PER_LONG.
highpmd
Shove pmd's into highmem by brute force.
O(1) buffered_rmqueue()
page_alloc.c rewrite for O(1) bulk transfers to/from per-cpu
lists. Some of this thing's performance problems were
corrected by the node-local per_cpu areas; I'm not entirely
sure what's going on here but it seems as if cachelines totally
unrelated to the algorithm are exploding wrt. modification cost.
It's encouraging to see that the algorithm's internals aren't
behaving like utter shite but discouraging to have no clue of
what's going wrong with it. I should at least be able to say
_why_ it sucks before throwing away something that doesn't
examine 95% of its input 95% of the time to keep something that
does examine 100% of its input 100% of the time...
lowmem_page_address() micro-optimization
Use page_to_pfn() instead of open-coding the discontig case.
trivial /proc/ BKL removals
A couple lock_kernel()'s were outright silly.
i386 pagetable cacheing
Piggyback on tlb.h stuff to cache pmd's and pte's, even when in
highmem. New and improved with a shootdown method for kswapd.
pgd_ctor
Use slab preconstruction for i386 pgd's.
O(1) proc_pid_readdir()
NIH'd from Manfred Spraul; walks the hashtable for fast seeks
O(1) proc_pid_statm()
NIH'd from Ben LaHaise; keeps count of proc_pid_statm()'s stats.
vfsmount_lock
NIH'd from Maneesh Soni and Dipankar Sarma; uses a separate
lock for vfsmounts
vfsmount RCU
NIH'd from Maneesh Soni and Dipankar Sarma; RCU's vfsmount_lock
mnt_move_lock
NIH'd from Maneesh Soni; uses a seqlock for ->mnt_parent
i386 kmap_atomic() micro-optimizations
Check pte_same() etc. and nop out kunmap_atomic() when possible.
adaptive mapping->page_lock
Use rwlocks when NR_CPUS > 8. NR_CPUS > 8 loves it.
4KB stacks, part 1
NIH'd from Ben LaHaise and Dave Hansen
s/8192/THREAD_SIZE/ cleanups
4KB stacks, part 2
NIH'd from Ben LaHaise and Dave Hansen
Switch to irq stacks in interrupts.
4KB stacks, part 3
NIH'd from Ben LaHaise and Dave Hansen
mcount-based stack overflow checking
4KB stacks, part 4
NIH'd from Ben LaHaise and Dave Hansen
Switch THREAD_SIZE on a config option.
partial objrmap
NIH'd from Martin Bligh and Dave McCracken
Walk ->i_mmap{,shared} for ptov resolution on file-backed pages.
i_mmap RCU
Use RCU rwlocking to replace mapping->i_shared_sem.
anobjrmap, part 1
NIH'd from Hugh Dickins
Core VM cleanups of some kind.
anobjrmap, part 2
NIH'd from Hugh Dickins
Prep things to let anonymous pages use ->mapping for other things.
anobjrmap, part 3
NIH'd from Hugh Dickins
Wipe pte_chains off the face of the earth.
anobjrmap, part 4
NIH'd from Hugh Dickins (and mutated in various ways)
Make a struct anon to look up anon pages with.
anobjrmap, part 5
NIH'd from Hugh Dickins
Reinvent pte_chains from scratch, totally different algorithm.
(Part 6 was partially dropped and partially folded into others.)
anon->lock RCU
Entirely analogous to ->i_mmap RCU for struct anons.
fs/exec.c sleeping kmap() removals
highmem.c TLB shootdowns are murder on SMP.
If only readdir() were so easy to fix...
miscellaneous micro-optimizations
inode_change_ok() BKL removal (from other trees)
push down ->mmap_sem to where O(1) proc_pid_statm() can avoid it
generic_file_llseek() for ramfs (from other trees)
nuke some extraneous crap in page_alloc.c and jack up batches
i386 per_cpu
Shove i386 per_cpu data into node-local memory via virtual
remapping and other disgusting hacks. For some weird reason
it shook up cacheline colors or some other horrifically
unpredictable factor enough to help that silly O(1)
buffered_rmqueue() thing. Also possible node-locality gains.
cpumask_t bugfixes
From recent -mm discussions.
CONFIG_MMAP_TOPDOWN
Top-down vma allocation; unfortunately various versions of glibc
hate this and all versions of NPTL and/or LinuxThreads do too...
files_struct RCU
NIH'd from Maneesh Soni and Dipankar Sarma
RCU locking for fd tables
redundant current removals
I don't trust gcc to stop recomputing current on every call.
fs_struct RCU
RCU locking for pwd's, altroots, etc.
less rmap_lock()'ing
Untangle page->mapcount and page->chain so ->mapcount can be
found without having to take a bitwise spinlock per page.
copy_page_range() never does the bitwise spinlocking at all.
zap_page_range() only does it for pages the unmapper was the
last to unmap. Hefty SMP speedup of a certain unmentionable
benchmark. Unfortunately increases sizeof(struct page).
kill files_lock
Use a split list to hold struct files so as not to pound
files_lock like a wild monkey. Even heftier SMP speedup
of the same unmentionable benchmark...
-- wli
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This archive was generated by hypermail 2b29 : Mon Jul 07 2003 - 22:00:29 EST