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    SubjectRe: [PATCH 1/3] printk: Fix kdb_trap_printk placement
    On Thu, Oct 12, 2017 at 12:03:04PM +0200, Petr Mladek wrote:
    > On Thu 2017-10-12 11:45:37, Petr Mladek wrote:
    > > Hi,
    > >
    > > I thought about this a lot from several angles. And I would prefer
    > > sligly different placement, see the patch below.
    > >
    > > On Thu 2017-09-28 14:18:24, Peter Zijlstra wrote:
    > > > Some people figured vprintk_emit() makes for a nice API and exported
    > > > it, bypassing the kdb trap.
    > >
    > > Sigh, printk() API is pretty complicated and this export
    > > made it much worse. Well, there are two things:
    > >
    > > First, kdb_trap_printk name is a bit misleading. It is not a
    > > generic trap of any printk message. Instead it seems to be
    > > used to redirect only particular messages from some existing
    > > functions, e.g. show_regs() called from kdb_dumpregs().
    > >
    > > Second, it seems that the only user of the exported vprintk_emit()
    > > is dev_vprintk_emit(). I believe that code using this wrapper
    > > is not called in the sections where kdb_trap_printk is incremented.
    >
    > Well, I wonder if we should go even further and stop exporting
    > vprintk_emit(). IMHO, the only reason was dev_print_emit() and
    > the ability to pass the extra "dict" parameter.

    You have my blessing there, but the device folks might have an opinion
    on that; Cc'ed Gregkh.

    > My aim is to redirect all the exported interfaces into vprintk_func
    > (need another name?) where the right implementation will be chosen
    > by the context (NMI, printk_safe, kdb, deferred?, printk_early, normal).
    >
    > In each case, I would like to have all these re-directions on a single
    > place to make the printk() code better readable.
    >
    > IMHO, it would make sense to do this clean up first before
    > this patchset adds more twists. But I am afraid that we will
    > meet some problems and it make take longer. I am open for
    > opinions.
    >
    > Best Regards,
    > Petr

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