From: Josh Poimboeuf <jpoimboe@xxxxxxxxxx> > Sent: 15 November 2019 17:47 > On Fri, Nov 15, 2019 at 04:51:24PM +0000, David Laight wrote: > > From: Shile Zhang > > > Sent: 15 November 2019 06:48 > > ... > > > arch/x86/kernel/unwind_orc.c | 8 +++++--- > > > 1 file changed, 5 insertions(+), 3 deletions(-) > > > > > > diff --git a/arch/x86/kernel/unwind_orc.c b/arch/x86/kernel/unwind_orc.c > > > index 332ae6530fa8..280da6fa9922 100644 > > > --- a/arch/x86/kernel/unwind_orc.c > > > +++ b/arch/x86/kernel/unwind_orc.c > > > @@ -273,9 +273,11 @@ void __init unwind_init(void) > > > return; > > > } > > > > > > - /* Sort the .orc_unwind and .orc_unwind_ip tables: */ > > > - sort(__start_orc_unwind_ip, num_entries, sizeof(int), orc_sort_cmp, > > > - orc_sort_swap); > > > + /* > > > + * Note, orc_unwind and orc_unwind_ip tables has been sorted in > > > + * vmlinux link phase by sorttable tool at build time. > > > + * Its ready for binary search now. > > > + */ > > > > How fast is sort() if the table is sorted? > > Relying on the kernel sources and build scripts always being in sync seems dangerous. > > Probably better to leave the sort in for a release of two. > > This patch comes after the build script changes, so they'd be in sync. > What would the concern be? Mostly that if, for any reason, the build script changes are missing nothing will detect the error - but the results will be very confusing. If the sort is fast for sorted inputs (some algorithms aren't) then leaving it in won't take that long. David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)
