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5d337b9194
The idea of a swap_device_lock per device, and a swap_list_lock over them all, is appealing; but in practice almost every holder of swap_device_lock must already hold swap_list_lock, which defeats the purpose of the split. The only exceptions have been swap_duplicate, valid_swaphandles and an untrodden path in try_to_unuse (plus a few places added in this series). valid_swaphandles doesn't show up high in profiles, but swap_duplicate does demand attention. However, with the hold time in get_swap_pages so much reduced, I've not yet found a load and set of swap device priorities to show even swap_duplicate benefitting from the split. Certainly the split is mere overhead in the common case of a single swap device. So, replace swap_list_lock and swap_device_lock by spinlock_t swap_lock (generally we seem to prefer an _ in the name, and not hide in a macro). If someone can show a regression in swap_duplicate, then probably we should add a hashlock for the swap_map entries alone (shorts being anatomic), so as to help the case of the single swap device too. Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org> |
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acpi | ||
asm-alpha | ||
asm-arm | ||
asm-arm26 | ||
asm-cris | ||
asm-frv | ||
asm-generic | ||
asm-h8300 | ||
asm-i386 | ||
asm-ia64 | ||
asm-m32r | ||
asm-m68k | ||
asm-m68knommu | ||
asm-mips | ||
asm-parisc | ||
asm-powerpc | ||
asm-ppc | ||
asm-ppc64 | ||
asm-s390 | ||
asm-sh | ||
asm-sh64 | ||
asm-sparc | ||
asm-sparc64 | ||
asm-um | ||
asm-v850 | ||
asm-x86_64 | ||
asm-xtensa | ||
linux | ||
math-emu | ||
media | ||
mtd | ||
net | ||
pcmcia | ||
rdma | ||
rxrpc | ||
scsi | ||
sound | ||
video |