Messages in this thread | | | Subject | Re: [PATCH 4/5] kmemtrace: SLUB hooks. | From | Matt Mackall <> | Date | Tue, 12 Aug 2008 21:09:59 -0500 |
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On Tue, 2008-08-12 at 18:29 +0300, Eduard - Gabriel Munteanu wrote: > On Mon, Aug 11, 2008 at 05:22:37PM +0300, Pekka Enberg wrote: > > On Mon, 2008-08-11 at 09:21 -0500, Christoph Lameter wrote: > > > Pekka Enberg wrote: > > > > > > > The function call is supposed to go away when we convert kmemtrace to > > > > use Mathieu's markers but I suppose even then we have a problem with > > > > inlining? > > > > > > The function calls are overwritten with NOPs? Or how does that work? > > > > I have no idea. Mathieu, Eduard? > > Yes, the code is patched at runtime. But AFAIK markers already provide > this stuff (called "immediate values"). Mathieu's tracepoints also do > it. But it's not available on all arches. x86 and x86-64 work as far as > I remember.
Did we ever see size(1) numbers for kernels with and without this support? I'm still a bit worried about adding branches to such a popular inline. Simply multiplying the branch test by the number of locations is pretty substantial, never mind the unlikely part of the branch.
-- Mathematics is the supreme nostalgia of our time.
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