Messages in this thread Patch in this message | | | Subject | Re: [PATCH] trace: reorder struct ring_buffer_per_cpu to remove padding on 64bit | From | Steven Rostedt <> | Date | Thu, 25 Mar 2010 09:38:10 -0400 |
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On Thu, 2010-03-25 at 11:27 +0000, Richard Kennedy wrote: > Reorder structure to remove 8 bytes of padding on 64 bit builds. > This shrinks the size to 128 bytes so allowing allocation from a smaller > slab & needed one fewer cache lines. >
Thanks!
Just curious, did you use Arnaldo's pahole utility to find this?
-- Steve
> Signed-off-by: Richard Kennedy <richard@rsk.demon.co.uk> > ---- > patch against 2.6.34-rc2 > compiled & booted on x86_64 > > regards > Richard > > diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c > index 05a9f83..421db5e 100644 > --- a/kernel/trace/ring_buffer.c > +++ b/kernel/trace/ring_buffer.c > @@ -422,6 +422,7 @@ int ring_buffer_print_page_header(struct trace_seq > *s) > */ > struct ring_buffer_per_cpu { > int cpu; > + atomic_t record_disabled; > struct ring_buffer *buffer; > spinlock_t reader_lock; /* serialize readers */ > arch_spinlock_t lock; > @@ -439,7 +440,6 @@ struct ring_buffer_per_cpu { > unsigned long read; > u64 write_stamp; > u64 read_stamp; > - atomic_t record_disabled; > }; > > struct ring_buffer { > >
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