Nick Piggin 35a82d1a53 [PATCH] optimise loop driver a bit ... Looks like locking can be optimised quite a lot. Increase lock widths slightly so lo_lock is taken fewer times per request. Also it was quite trivial to cover lo_pending with that lock, and remove the atomic requirement. This also makes memory ordering explicitly correct, which is nice (not that I particularly saw any mem ordering bugs). Test was reading 4 250MB files in parallel on ext2-on-tmpfs filesystem (1K block size, 4K page size). System is 2 socket Xeon with HT (4 thread). intel:/home/npiggin# umount /dev/loop0 ; mount /dev/loop0 /mnt/loop ; /usr/bin/time ./mtloop.sh Before: 0.24user 5.51system 0:02.84elapsed 202%CPU (0avgtext+0avgdata 0maxresident)k 0.19user 5.52system 0:02.88elapsed 198%CPU (0avgtext+0avgdata 0maxresident)k 0.19user 5.57system 0:02.89elapsed 198%CPU (0avgtext+0avgdata 0maxresident)k 0.22user 5.51system 0:02.90elapsed 197%CPU (0avgtext+0avgdata 0maxresident)k 0.19user 5.44system 0:02.91elapsed 193%CPU (0avgtext+0avgdata 0maxresident)k After: 0.07user 2.34system 0:01.68elapsed 143%CPU (0avgtext+0avgdata 0maxresident)k 0.06user 2.37system 0:01.68elapsed 144%CPU (0avgtext+0avgdata 0maxresident)k 0.06user 2.39system 0:01.68elapsed 145%CPU (0avgtext+0avgdata 0maxresident)k 0.06user 2.36system 0:01.68elapsed 144%CPU (0avgtext+0avgdata 0maxresident)k 0.06user 2.42system 0:01.68elapsed 147%CPU (0avgtext+0avgdata 0maxresident)k Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>		2005-06-23 09:45:18 -07:00
..
acpi
asm-alpha	[PATCH] remove non-DISCONTIG use of pgdat->node_mem_map	2005-06-23 09:45:00 -07:00
asm-arm	Merge master.kernel.org:/home/rmk/linux-2.6-arm	2005-06-22 14:51:06 -07:00
asm-arm26	[PATCH] Remove obsolete HAVE_ARCH_GET_SIGNAL_TO_DELIVER?	2005-06-12 20:43:21 -07:00
asm-cris
asm-frv
asm-generic	[PATCH] x86/x86_64: pcibus_to_node	2005-06-23 09:45:08 -07:00
asm-h8300
asm-i386	[PATCH] xen: x86: Rename usermode macro	2005-06-23 09:45:14 -07:00
asm-ia64	[PATCH] ia64: Selectable Timer Interrupt Frequency	2005-06-23 09:45:10 -07:00
asm-m32r	[PATCH] m32r: build fix for asm-m32r/topology.h	2005-06-23 09:45:08 -07:00
asm-m68k
asm-m68knommu
asm-mips	[PATCH] mips: add vr41xx gpio support	2005-06-21 18:46:32 -07:00
asm-parisc	[PATCH] remove non-DISCONTIG use of pgdat->node_mem_map	2005-06-23 09:45:00 -07:00
asm-ppc	[PATCH] ppc32: Clean up NUM_TLBCAMS usage for Freescale Book-E PPC's	2005-06-21 18:46:24 -07:00
asm-ppc64	[PATCH] ppc64: pcibus_to_node fix	2005-06-23 09:45:08 -07:00
asm-s390	[PATCH] smp_processor_id() cleanup	2005-06-21 18:46:13 -07:00
asm-sh	[PATCH] Hugepage consolidation	2005-06-21 18:46:15 -07:00
asm-sh64	[PATCH] Hugepage consolidation	2005-06-21 18:46:15 -07:00
asm-sparc	[PATCH] smp_processor_id() cleanup	2005-06-21 18:46:13 -07:00
asm-sparc64	[PATCH] Hugepage consolidation	2005-06-21 18:46:15 -07:00
asm-um	[PATCH] smp_processor_id() cleanup	2005-06-21 18:46:13 -07:00
asm-v850
asm-x86_64	[PATCH] xen: x86_64: Add macro for debugreg	2005-06-23 09:45:14 -07:00
linux	[PATCH] optimise loop driver a bit	2005-06-23 09:45:18 -07:00
math-emu
media
mtd
net	[X25]: Fast select with no restriction on response	2005-06-22 22:16:17 -07:00
pcmcia
rxrpc
scsi
sound	[PATCH] create a kstrdup library function	2005-06-23 09:45:18 -07:00
video