Re: [PATCH RFC 3/5] kbuild/extable: Hook up sortextable into the build system.

2011-11-20 Thread Michal Marek
On 18.11.2011 20:37, David Daney wrote: + $(if $(CONFIG_BUILDTIME_EXTABLE_SORT), \ + $(Q)$(if $($(quiet)cmd_sortextable),\ + echo ' $($(quiet)cmd_sortextable) vmlinux' ) \ + $(cmd_sortextable) vmlinux)

Re: [PATCH RFC 0/5] Speed booting by sorting exception tables at build time.

2011-11-20 Thread Mike Frysinger
On Friday 18 November 2011 14:37:43 David Daney wrote: I noticed when booting MIPS64 kernels that sorting of the main __ex_table was taking a long time (2,692,220 cycles or 3.3 mS at 800MHz to be exact). That is not too bad for real silicon implementations, but when running on a slow

Re: [PATCH RFC 1/5] scripts: Add sortextable to sort the kernel's exception table.

2011-11-20 Thread Mike Frysinger
On Friday 18 November 2011 14:37:44 David Daney wrote: --- /dev/null +++ b/scripts/sortextable.c +/* + * sortextable.c: Sort the kernel's exception table + * + * Copyright 2011 Cavium, Inc. + * + * Based on code taken from recortmcount.c which is: seems like it'd be nice if the duplicate

Re: [PATCH RFC 1/5] scripts: Add sortextable to sort the kernel's exception table.

2011-11-20 Thread H. Peter Anvin
On 11/18/2011 11:37 AM, David Daney wrote: From: David Daney david.da...@cavium.com Using this build-time sort saves time booting as we don't have to burn cycles sorting the exception table. If we're going to do this at build time, I would suggest using a collisionless hash instead. The

Re: [PATCH RFC 1/5] scripts: Add sortextable to sort the kernel's exception table.

2011-11-20 Thread H. Peter Anvin
On 11/20/2011 03:26 PM, H. Peter Anvin wrote: On 11/18/2011 11:37 AM, David Daney wrote: From: David Daney david.da...@cavium.com Using this build-time sort saves time booting as we don't have to burn cycles sorting the exception table. If we're going to do this at build time, I would

Re: [PATCH RFC 1/5] scripts: Add sortextable to sort the kernel's exception table.

2011-11-20 Thread David Woodhouse
On Sun, 2011-11-20 at 15:26 -0800, H. Peter Anvin wrote: If we're going to do this at build time, I would suggest using a collisionless hash instead. The lookup time for those are O(1), but they definitely need to be done at build time. Is the lookup time really an issue? -- dwmw2

Re: [PATCH RFC 1/5] scripts: Add sortextable to sort the kernel's exception table.

2011-11-20 Thread H. Peter Anvin
On 11/20/2011 03:28 PM, David Woodhouse wrote: On Sun, 2011-11-20 at 15:26 -0800, H. Peter Anvin wrote: If we're going to do this at build time, I would suggest using a collisionless hash instead. The lookup time for those are O(1), but they definitely need to be done at build time. Is