From: Andy Lutomirski Date: Fri, 5 Sep 2014 22:13:53 +0000 (-0700) Subject: x86, entry: Only call user_exit if TIF_NOHZ X-Git-Tag: fixes-against-v3.18-rc2~86^2~3 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=fd143b210e685f0c4b37895f03fb79cd0555b00d;p=pandora-kernel.git x86, entry: Only call user_exit if TIF_NOHZ The RCU context tracking code requires that arch code call user_exit() on any entry into kernel code if TIF_NOHZ is set. This patch adds a check for TIF_NOHZ and a comment to the syscall entry tracing code. The main purpose of this patch is to make the code easier to follow: one can read the body of user_exit and of every function it calls without finding any explanation of why it's called for traced syscalls but not for untraced syscalls. This makes it clear when user_exit() is necessary. Cc: Frederic Weisbecker Signed-off-by: Andy Lutomirski Link: http://lkml.kernel.org/r/0b13e0e24ec0307d67ab7a23b58764f6b1270116.1409954077.git.luto@amacapital.net Signed-off-by: H. Peter Anvin --- Reading git-diff-tree failed