Commit 0f133021 authored Jun 12, 2019 by Daniel Bristot de Oliveira Committed by Ingo Molnar Jun 17, 2019

jump_label: Sort entries of the same key by the code



In the batching mode, all the entries of a given key are updated at once.
During the update of a key, a hit in the int3 handler will check if the
hitting code address belongs to one of these keys.

To optimize the search of a given code in the vector of entries being
updated, a binary search is used. The binary search relies on the order
of the entries of a key by its code. Hence the keys need to be sorted
by the code too, so sort the entries of a given key by the code.

Signed-off-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Chris von Recklinghausen <crecklin@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Scott Wood <swood@redhat.com>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/f57ae83e0592418ba269866bb7ade570fc8632e0.1560325897.git.bristot@redhat.com


Signed-off-by: Ingo Molnar <mingo@kernel.org>

parent 4cc6620b

kernel/jump_label.c

+14 −0

Original line number	Diff line number	Diff line
		@@ -37,12 +37,26 @@ static int jump_label_cmp(const void a, const void b)
		const struct jump_entry *jea = a;
		const struct jump_entry *jeb = b;

		/*
		* Entrires are sorted by key.
		*/
		if (jump_entry_key(jea) < jump_entry_key(jeb))
		return -1;

		if (jump_entry_key(jea) > jump_entry_key(jeb))
		return 1;

		/*
		* In the batching mode, entries should also be sorted by the code
		* inside the already sorted list of entries, enabling a bsearch in
		* the vector.
		*/
		if (jump_entry_code(jea) < jump_entry_code(jeb))
		return -1;

		if (jump_entry_code(jea) > jump_entry_code(jeb))
		return 1;

		return 0;
		}

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