On Mon, Sep 21, 2015 at 06:13:01PM -0400, Murali Karicheri wrote: > Hi Maintainer, > > The below commit fixes the Warning shown in the trace below when debug > options are enabled in the kernel build. Could you please merge this to > address the issue for v4.1.9? > > Thanks > ============================================================================ > commit 3302caddf10ad50710dbb7a94ccbdb3ad5bf1412 > Author: Russell King <rmk+kernel@xxxxxxxxxxxxxxxx> > Date: Thu Aug 20 16:13:37 2015 +0100 > > ARM: entry: efficiency cleanups > > Make the "fast" syscall return path fast again. The addition of IRQ > tracing and context tracking has made this path grossly inefficient. > We can do much better if these options are enabled if we save the > syscall return code on the stack - we then don't need to save a bunch > of registers around every single callout to C code. > > Acked-by: Will Deacon <will.deacon@xxxxxxx> > Signed-off-by: Russell King <rmk+kernel@xxxxxxxxxxxxxxxx> > ================================================================================ > > Warning log below which is addressed by above commit. How does the above git commit id, solve the warning you show here: > > > [ 17.401337] ------------[ cut here ]------------ > [ 17.405991] WARNING: CPU: 2 PID: 1201 at kernel/locking/lockdep.c:3557 > check_flags.part.37+0x224/0x228() > [ 17.415508] DEBUG_LOCKS_WARN_ON(current->hardirqs_enabled) > [ 17.420836] Modules linked in: > [ 17.424087] CPU: 2 PID: 1201 Comm: udevd Tainted: G W > 4.1.6-01270-gcdac6fd #1 > [ 17.432379] Hardware name: Keystone > [ 17.435894] [<c00178e4>] (unwind_backtrace) from [<c0013cbc>] > (show_stack+0x10/0x14) > [ 17.443673] [<c0013cbc>] (show_stack) from [<c05ff398>] > (dump_stack+0x84/0xc4) > [ 17.450926] [<c05ff398>] (dump_stack) from [<c0028990>] > (warn_slowpath_common+0x84/0xb4) > [ 17.459048] [<c0028990>] (warn_slowpath_common) from [<c00289f0>] > (warn_slowpath_fmt+0x30/0x40) > [ 17.467781] [<c00289f0>] (warn_slowpath_fmt) from [<c006c37c>] > (check_flags.part.37+0x224/0x228) > [ 17.476601] [<c006c37c>] (check_flags.part.37) from [<c006ce48>] > (lock_is_held+0x88/0x94) > [ 17.484811] [<c006ce48>] (lock_is_held) from [<c008eb9c>] > (rcu_note_context_switch+0x854/0x8c0) > [ 17.493545] [<c008eb9c>] (rcu_note_context_switch) from [<c0600b54>] > (__schedule+0x40/0x844) > [ 17.502017] [<c0600b54>] (__schedule) from [<c0601398>] > (schedule+0x40/0x98) > [ 17.509097] [<c0601398>] (schedule) from [<c001364c>] > (do_work_pending+0x24/0xb0) > [ 17.516610] [<c001364c>] (do_work_pending) from [<c000ffc4>] > (work_pending+0xc/0x20) > [ 17.524380] ---[ end trace fe0042166f5d3227 ]--- > [ 17.529009] possible reason: unannotated irqs-off. > [ 17.533813] irq event stamp: 331979 > [ 17.537308] hardirqs last enabled at (331979): [<c000fffc>] > no_work_pending+0x8/0x30 > [ 17.545172] hardirqs last disabled at (331978): [<c000ffe4>] > ret_slow_syscall+0xc/0x10 > [ 17.553123] softirqs last enabled at (327182): [<c002ca90>] > __do_softirq+0x4dc/0x6cc > [ 17.560987] softirqs last disabled at (327177): [<c002cf88>] > irq_exit+0x98/0xcc ??? The commit you reference is for a speedup, not a "fix a warning" issue. Also, I can't take stuff in 4.1 that is not also in 4.2-stable, please test it there as well. thanks, greg k-h -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html