stop_machine: struct cpu_stopper, remove alignment padding on 64 bits
PATCH 1/1 stop_machine: struct cpu_stopper, remove alignment padding on 64 bits
Reorder elements in structure cpu_stopper to remove alignment padding on 64 bit builds, this shrinks its size from 40 to 32 bytes saving 8 bytes per cpu.
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patch against 2.6.35
compiled & tested on x86_64
regards
Richard
kernel/stop_machine.c +1 -1
@@ -35,9 +35,9 @@ struct cpu_stop_done {/* the actual stopper, one per every possible cpu, enabled on online cpus */ struct cpu_stopper {spinlock_t lock; +bool enabled;/* is this stopper enabled? */ struct list_head works;/* list of pending works */ struct task_struct *thread;/* stopper thread */ -bool enabled;/* is this stopper enabled? */ }; static DEFINE_PER_CPU(struct cpu_stopper, cpu_stopper);
Quoted 5 lines · Richard Kennedy
Reorder elements in structure
cpu_stopperto remove alignment padding on 64 bit builds, this shrinks its size from 40 to 32 bytes saving 8 bytes per cpu.Signed-off-by Richard Kennedy <[email protected]>
Looks good to me. Tejun will you take it or should I send it Ingo wards?
Quoted 18 lines
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kernel/stop_machine.c +1
-1@@ -35,9 +35,9 @@ struct cpu_stop_done {/* the actual stopper, one per every possible cpu, enabled on online cpus */ struct cpu_stopper {spinlock_t lock; +bool enabled;/* is this stopper enabled? */ struct list_head works;/* list of pending works */ struct task_struct *thread;/* stopper thread */ -bool enabled;/* is this stopper enabled? */ }; static DEFINE_PER_CPU(struct cpu_stopper, cpu_stopper);
Hello, Peter.
Quoted 8 lines · Peter Zijlstra
Quoted 5 lines · Richard Kennedy
Reorder elements in structure
cpu_stopperto remove alignment padding on 64 bit builds, this shrinks its size from 40 to 32 bytes saving 8 bytes per cpu.Signed-off-by Richard Kennedy <[email protected]>Looks good to me. Tejun will you take it or should I send it Ingo wards?
I already asked whether Andrew could take it but routing through Ingo's tree would be good too. Let's wait for Andrew a bit for now.
Thank you.
Signature · 1 line
tejun
Hello,
Quoted 5 lines · Richard Kennedy
Reorder elements in structure
cpu_stopperto remove alignment padding on 64 bit builds, this shrinks its size from 40 to 32 bytes saving 8 bytes per cpu.Signed-off-by Richard Kennedy <[email protected]>
Andrew, do you mind routing this one through your tree?
http://lkml.org/lkml/2010/8/5/168
Thank you.
Signature · 1 line
tejun