Commit-ID: 0f133021bd82548a33580bfb7b055e8857f46c2a Gitweb: https://git.kernel.org/tip/0f133021bd82548a33580bfb7b055e8857f46c2a Author: Daniel Bristot de Oliveira <bristot@xxxxxxxxxx> AuthorDate: Wed, 12 Jun 2019 11:57:28 +0200 Committer: Ingo Molnar <mingo@xxxxxxxxxx> CommitDate: Mon, 17 Jun 2019 12:09:21 +0200 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@xxxxxxxxxx> Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> Cc: Borislav Petkov <bp@xxxxxxxxx> Cc: Chris von Recklinghausen <crecklin@xxxxxxxxxx> Cc: Clark Williams <williams@xxxxxxxxxx> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Cc: H. Peter Anvin <hpa@xxxxxxxxx> Cc: Jason Baron <jbaron@xxxxxxxxxx> Cc: Jiri Kosina <jkosina@xxxxxxx> Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Cc: Marcelo Tosatti <mtosatti@xxxxxxxxxx> Cc: Masami Hiramatsu <mhiramat@xxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Scott Wood <swood@xxxxxxxxxx> Cc: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Link: https://lkml.kernel.org/r/f57ae83e0592418ba269866bb7ade570fc8632e0.1560325897.git.bristot@xxxxxxxxxx Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> --- kernel/jump_label.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/kernel/jump_label.c b/kernel/jump_label.c index 24f0d3b1526b..ca00ac10d9b9 100644 --- a/kernel/jump_label.c +++ b/kernel/jump_label.c @@ -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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