From mboxrd@z Thu Jan 1 00:00:00 1970 From: huawei.libin@huawei.com (libin) Date: Fri, 4 Dec 2015 09:00:40 +0800 Subject: [PATCH] arm64: ftrace: stop using kstop_machine to enable/disable tracing In-Reply-To: <20151203103139.35648cc2@gandalf.local.home> References: <1448697009-17211-1-git-send-email-huawei.libin@huawei.com> <20151202123654.GC4523@arm.com> <56600992.4040005@huawei.com> <20151203093821.GD7023@arm.com> <20151203100525.70cc40de@gandalf.local.home> <20151203150926.GG11337@arm.com> <20151203103139.35648cc2@gandalf.local.home> Message-ID: <5660E5B8.2050103@huawei.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Thanks very much to Will and Steve for the wonderful comments, I will modify the commit message, and remove the misleading comments about module text disappearing case. Thanks again, Li Bin on 2015/12/3 23:31, Steven Rostedt wrote: > On Thu, 3 Dec 2015 15:09:26 +0000 > Will Deacon wrote: > >> Yeah, I think the comments on x86 and arm64 are out of date. They also >> mention the freeing of __init sections -- is that still a concern? > No we black list them, any section that we are not sure will be there > when we expect it to has recordmcount.c nop out the calls to mcount and > they are ignored. Remember the e1000e bug? This was the reproducer. > > Anyway, on my todo list is to allow init sections to be traced. To do > so would mean that I need to add generic code that lets ftrace know to > remove init sections at boot up. Right now (or at least the last time I > checked, which was back in 2009), every arch had its own way of freeing > init memory. If that has changed, or I can just place a hook where it > happens (which is probably the easy part), I can allow init code to be > traced too. > > -- Steve > > > . >