hi Johannes and Larry, On Thu, Apr 12, 2012 at 9:25 PM, Johannes Berg <johannes@xxxxxxxxxxxxxxxx> wrote: > On Thu, 2012-04-12 at 10:51 -0500, Larry Finger wrote: >> On 04/11/2012 10:54 PM, Johannes Berg wrote: >> > >> > What do you mean by "every time"? I wouldn't expect the timer to fire >> > every time you set up aggregation etc., the timer firing is a special >> > case to start with. >> >> I meant it is intermittent, or it required some special setup that I have not >> duplicated, as I have seen the condition only once. > > Ok. I suspect that's explained by the fact that the timer is an error > case anyway, so you've probably never seen that error case again. It's > still puzzling though since the code looks fine to me. > > johannes > > -- > To unsubscribe from this list: send the line "unsubscribe linux-wireless" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html May 1 14:34:51 shafi-laptop kernel: [ 83.216284] =============================== May 1 14:34:51 shafi-laptop kernel: [ 83.216286] [ INFO: suspicious RCU usage. ] May 1 14:34:51 shafi-laptop kernel: [ 83.216289] 3.4.0-rc3-wl #16 Not tainted May 1 14:34:51 shafi-laptop kernel: [ 83.216291] ------------------------------- May 1 14:34:51 shafi-laptop kernel: [ 83.216293] net/mac80211/sta_info.h:456 suspicious rcu_dereference_protected() usage! May 1 14:34:51 shafi-laptop kernel: [ 83.216295] May 1 14:34:51 shafi-laptop kernel: [ 83.216296] other info that might help us debug this: May 1 14:34:51 shafi-laptop kernel: [ 83.216297] May 1 14:34:51 shafi-laptop kernel: [ 83.216299] May 1 14:34:51 shafi-laptop kernel: [ 83.216299] rcu_scheduler_active = 1, debug_locks = 1 May 1 14:34:51 shafi-laptop kernel: [ 83.216302] 2 locks held by kmemleak/52: May 1 14:34:51 shafi-laptop kernel: [ 83.216303] #0: (scan_mutex){+.+...}, at: [<c024d343>] kmemleak_scan_thread+0x53/0xc0 May 1 14:34:51 shafi-laptop kernel: [ 83.216313] #1: (&tid_tx->session_timer){+.-...}, at: [<c0144fdf>] run_timer_softirq+0xcf/0x400 May 1 14:34:51 shafi-laptop kernel: [ 83.216321] May 1 14:34:51 shafi-laptop kernel: [ 83.216322] stack backtrace: May 1 14:34:51 shafi-laptop kernel: [ 83.216325] Pid: 52, comm: kmemleak Not tainted 3.4.0-rc3-wl #16 May 1 14:34:51 shafi-laptop kernel: [ 83.216327] Call Trace: May 1 14:34:51 shafi-laptop kernel: [ 83.216332] [<c0191726>] lockdep_rcu_suspicious+0xc6/0x100 May 1 14:34:51 shafi-laptop kernel: [ 83.216351] [<f835b14d>] sta_tx_agg_session_timer_expired+0xcd/0x100 [mac80211] May 1 14:34:51 shafi-laptop kernel: [ 83.216355] [<c014506d>] run_timer_softirq+0x15d/0x400 May 1 14:34:51 shafi-laptop kernel: [ 83.216358] [<c0144fdf>] ? run_timer_softirq+0xcf/0x400 May 1 14:34:51 shafi-laptop kernel: [ 83.216373] [<f835b080>] ? sta_addba_resp_timer_expired+0x240/0x240 [mac80211] May 1 14:34:51 shafi-laptop kernel: [ 83.216380] [<c013d56f>] __do_softirq+0xaf/0x310 May 1 14:34:51 shafi-laptop kernel: [ 83.216384] [<c013d4c0>] ? __hrtimer_tasklet_trampoline+0x20/0x20 May 1 14:34:51 shafi-laptop kernel: [ 83.216386] <IRQ> [<c013cc65>] ? irq_exit+0xb5/0xd0 May 1 14:34:51 shafi-laptop kernel: [ 83.216393] [<c06b74a9>] ? smp_apic_timer_interrupt+0x59/0x88 May 1 14:34:51 shafi-laptop kernel: [ 83.216398] [<c03d8edc>] ? trace_hardirqs_off_thunk+0xc/0x10 May 1 14:34:51 shafi-laptop kernel: [ 83.216402] [<c06afc36>] ? apic_timer_interrupt+0x36/0x40 May 1 14:34:51 shafi-laptop kernel: [ 83.216405] [<c019007b>] ? rcu_read_lock_sched_held+0x1b/0x70 May 1 14:34:51 shafi-laptop kernel: [ 83.216409] [<c06af58e>] ? _raw_spin_unlock_irqrestore+0x3e/0x70 May 1 14:34:51 shafi-laptop kernel: [ 83.216412] [<c024bf4b>] ? scan_gray_list+0x12b/0x180 May 1 14:34:51 shafi-laptop kernel: [ 83.216415] [<c024c815>] ? kmemleak_scan+0x235/0x8c0 May 1 14:34:51 shafi-laptop kernel: [ 83.216418] [<c024c5e0>] ? kmemleak_seq_next+0x130/0x130 May 1 14:34:51 shafi-laptop kernel: [ 83.216422] [<c024d2f0>] ? kmemleak_write+0x450/0x450 May 1 14:34:51 shafi-laptop kernel: [ 83.216425] [<c024d2f0>] ? kmemleak_write+0x450/0x450 May 1 14:34:51 shafi-laptop kernel: [ 83.216428] [<c024d348>] ? kmemleak_scan_thread+0x58/0xc0 May 1 14:34:51 shafi-laptop kernel: [ 83.216431] [<c01590a4>] ? kthread+0x84/0x90 May 1 14:34:51 shafi-laptop kernel: [ 83.216435] [<c0159020>] ? __init_kthread_worker+0x60/0x60 May 1 14:34:51 shafi-laptop kernel: [ 83.216438] [<c06b7306>] ? kernel_thread_helper+0x6/0x10 May 1 14:34:54 shafi-laptop kernel: [ 86.692061] wlan0: no IPv6 routers present May 1 14:34:58 shafi-laptop kernel: [ 90.691571] cfg80211: Found new beacon on frequency: 2467 MHz (Ch 12) on phy0 i just looked into the code and compared it with sta_addba_resp_timer_expired and thought whether we should do this.. diff --git a/net/mac80211/agg-tx.c b/net/mac80211/agg-tx.c index 5b7053c..e4da258 100644 --- a/net/mac80211/agg-tx.c +++ b/net/mac80211/agg-tx.c @@ -421,21 +421,25 @@ static void sta_tx_agg_session_timer_expired(unsigned long data) struct tid_ampdu_tx *tid_tx; unsigned long timeout; + rcu_read_lock(); tid_tx = rcu_dereference_protected_tid_tx(sta, *ptid); - if (!tid_tx) + if (!tid_tx) { + rcu_read_unlock(); return; + } timeout = tid_tx->last_tx + TU_TO_JIFFIES(tid_tx->timeout); if (time_is_after_jiffies(timeout)) { mod_timer(&tid_tx->session_timer, timeout); + rcu_read_unlock(); return; } #ifdef CONFIG_MAC80211_HT_DEBUG printk(KERN_DEBUG "tx session timer expired on tid %d\n", (u16)*ptid); #endif - ieee80211_stop_tx_ba_session(&sta->sta, *ptid); + rcu_read_unlock(); } int i -- thanks, shafi -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
