From: Christoph Lameter <clameter@engr.sgi.com>
To: Rusty Lynch <rusty.lynch@intel.com>
Cc: linux-mm@kvack.org, prasanna@in.ibm.com,
linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org,
anil.s.keshavamurthy@intel.com
Subject: Re:[PATCH] Only process_die notifier in ia64_do_page_fault if KPROBES is configured.
Date: Fri, 26 Aug 2005 16:05:50 -0700 (PDT) [thread overview]
Message-ID: <Pine.LNX.4.62.0508261559450.17433@schroedinger.engr.sgi.com> (raw)
In-Reply-To: <200508262246.j7QMkEoT013490@linux.jf.intel.com>
On Fri, 26 Aug 2005, Rusty Lynch wrote:
> Just to be sure everyone understands the overhead involved, kprobes only
> registers a single notifier. If kprobes is disabled (CONFIG_KPROBES is
> off) then the overhead on a page fault is the overhead to execute an empty
> notifier chain.
Its the overhead of using registers to pass parameters, performing a
function call that does nothing etc. A waste of computing resources. All
of that unconditionally in a performance critical execution path that
is executed a gazillion times for an optional feature that I frankly
find not useful at all and that is disabled by default.
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next prev parent reply other threads:[~2005-08-26 23:05 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-08-26 22:46 Rusty Lynch
2005-08-26 23:05 ` Christoph Lameter [this message]
2005-08-27 0:24 ` [PATCH] " Andi Kleen
2005-08-30 0:19 ` Rusty Lynch
2005-08-30 1:08 ` Andi Kleen
2005-08-30 3:28 ` Christoph Lameter
2005-08-30 11:18 ` Matthew Wilcox
2005-09-19 18:22 ` Christoph Lameter
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