swapfile: swap allocation cycle if nonrot
commitc60aa176c6de82703f064082b909496fc4fee956
authorHugh Dickins <hugh@veritas.com>
Tue, 6 Jan 2009 22:39:55 +0000 (6 14:39 -0800)
committerLinus Torvalds <torvalds@linux-foundation.org>
Tue, 6 Jan 2009 23:59:06 +0000 (6 15:59 -0800)
tree2a6e58bda416af2c87f470023041f7049dcf1167
parent20137a490f397d9c01fc9fadd83a8d198bda4477
swapfile: swap allocation cycle if nonrot

Though attempting to find free clusters (Andrea), swap allocation has
always restarted its searches from the beginning of the swap area (sct),
to reduce seek times between swap pages, by not scattering them all over
the partition.

But on a solidstate swap device, seeks are cheap, and block remapping to
level the wear may be limited by zones: in that case it's better to cycle
around the whole partition.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: Joern Engel <joern@logfs.org>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Donjun Shin <djshin90@gmail.com>
Cc: Tejun Heo <teheo@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/swapfile.c