Hi Shaohua, Shaohua Li wrote: > Hi, > On Tue, 2008-03-11 at 02:25 +0800, Masami Hiramatsu wrote: >> Shaohua Li wrote: >>> On Sat, 2008-03-08 at 00:01 +0800, Masami Hiramatsu wrote: >>> There is no lock to protect the flag. If one cpu invokes other_kp >> and >>> the other cpu is changing the flag, what's the result? >> I think that other cpu never change the flag, because the caller of >> this >> function(__register_kprobe) locks kprobe_mutex in kernel/kprobes.c. > I mean if one cpu is doing register_kprobe, which will change other_kp's > flag. Another cpu is running into other_kp's break point, which will > look at the flag, there is a window (between the second cpu looks at the > flag and doing boost) the first cpu can change the flag in the window. > It appears we will lose one probe, but not sure if this is over > thinking. Sure, it is possible to lose just one probe in that time, but in next time, we do not lose it. So, I think it is not a problem. Thanks, -- Masami Hiramatsu Software Engineer Hitachi Computer Products (America) Inc. Software Solutions Division e-mail: mhiramat@xxxxxxxxxx -- To unsubscribe from this list: send the line "unsubscribe linux-ia64" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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