From: Sujith Manoharan <c_manoha@xxxxxxxxxxxxxxxx> This option has not been enabled by default in any distribution, has never been enabled in OpenWrt and no developer has asked for this information in a bug report. Dumping pages of random values doesn't help debugging, remove this option (along with the vmalloc() abuse). Signed-off-by: Sujith Manoharan <c_manoha@xxxxxxxxxxxxxxxx> --- drivers/net/wireless/ath/ath9k/Kconfig | 8 - drivers/net/wireless/ath/ath9k/debug.c | 337 --------------------------------- drivers/net/wireless/ath/ath9k/debug.h | 20 -- drivers/net/wireless/ath/ath9k/init.c | 3 - drivers/net/wireless/ath/ath9k/link.c | 1 - drivers/net/wireless/ath/ath9k/main.c | 1 - 6 files changed, 370 deletions(-) diff --git a/drivers/net/wireless/ath/ath9k/Kconfig b/drivers/net/wireless/ath/ath9k/Kconfig index 17507dc..ec33c80 100644 --- a/drivers/net/wireless/ath/ath9k/Kconfig +++ b/drivers/net/wireless/ath/ath9k/Kconfig @@ -84,14 +84,6 @@ config ATH9K_DFS_CERTIFIED developed. At this point enabling this option won't do anything except increase code size. -config ATH9K_MAC_DEBUG - bool "Atheros MAC statistics" - depends on ATH9K_DEBUGFS - default y - ---help--- - This option enables collection of statistics for Rx/Tx status - data and some other MAC related statistics - config ATH9K_RATE_CONTROL bool "Atheros ath9k rate control" depends on ATH9K diff --git a/drivers/net/wireless/ath/ath9k/debug.c b/drivers/net/wireless/ath/ath9k/debug.c index e6307b8..fc96ad3 100644 --- a/drivers/net/wireless/ath/ath9k/debug.c +++ b/drivers/net/wireless/ath/ath9k/debug.c @@ -738,8 +738,6 @@ void ath_debug_stat_tx(struct ath_softc *sc, struct ath_buf *bf, struct ath_tx_status *ts, struct ath_txq *txq, unsigned int flags) { -#define TX_SAMP_DBG(c) (sc->debug.bb_mac_samp[sc->debug.sampidx].ts\ - [sc->debug.tsidx].c) int qnum = txq->axq_qnum; TX_STAT_INC(qnum, tx_pkts_all); @@ -771,37 +769,6 @@ void ath_debug_stat_tx(struct ath_softc *sc, struct ath_buf *bf, TX_STAT_INC(qnum, data_underrun); if (ts->ts_flags & ATH9K_TX_DELIM_UNDERRUN) TX_STAT_INC(qnum, delim_underrun); - -#ifdef CONFIG_ATH9K_MAC_DEBUG - spin_lock(&sc->debug.samp_lock); - TX_SAMP_DBG(jiffies) = jiffies; - TX_SAMP_DBG(rssi_ctl0) = ts->ts_rssi_ctl0; - TX_SAMP_DBG(rssi_ctl1) = ts->ts_rssi_ctl1; - TX_SAMP_DBG(rssi_ctl2) = ts->ts_rssi_ctl2; - TX_SAMP_DBG(rssi_ext0) = ts->ts_rssi_ext0; - TX_SAMP_DBG(rssi_ext1) = ts->ts_rssi_ext1; - TX_SAMP_DBG(rssi_ext2) = ts->ts_rssi_ext2; - TX_SAMP_DBG(rateindex) = ts->ts_rateindex; - TX_SAMP_DBG(isok) = !!(ts->ts_status & ATH9K_TXERR_MASK); - TX_SAMP_DBG(rts_fail_cnt) = ts->ts_shortretry; - TX_SAMP_DBG(data_fail_cnt) = ts->ts_longretry; - TX_SAMP_DBG(rssi) = ts->ts_rssi; - TX_SAMP_DBG(tid) = ts->tid; - TX_SAMP_DBG(qid) = ts->qid; - - if (ts->ts_flags & ATH9K_TX_BA) { - TX_SAMP_DBG(ba_low) = ts->ba_low; - TX_SAMP_DBG(ba_high) = ts->ba_high; - } else { - TX_SAMP_DBG(ba_low) = 0; - TX_SAMP_DBG(ba_high) = 0; - } - - sc->debug.tsidx = (sc->debug.tsidx + 1) % ATH_DBG_MAX_SAMPLES; - spin_unlock(&sc->debug.samp_lock); -#endif - -#undef TX_SAMP_DBG } static const struct file_operations fops_xmit = { @@ -915,8 +882,6 @@ static ssize_t read_file_recv(struct file *file, char __user *user_buf, void ath_debug_stat_rx(struct ath_softc *sc, struct ath_rx_status *rs) { #define RX_PHY_ERR_INC(c) sc->debug.stats.rxstats.phy_err_stats[c]++ -#define RX_SAMP_DBG(c) (sc->debug.bb_mac_samp[sc->debug.sampidx].rs\ - [sc->debug.rsidx].c) RX_STAT_INC(rx_pkts_all); sc->debug.stats.rxstats.rx_bytes_all += rs->rs_datalen; @@ -940,27 +905,7 @@ void ath_debug_stat_rx(struct ath_softc *sc, struct ath_rx_status *rs) RX_PHY_ERR_INC(rs->rs_phyerr); } -#ifdef CONFIG_ATH9K_MAC_DEBUG - spin_lock(&sc->debug.samp_lock); - RX_SAMP_DBG(jiffies) = jiffies; - RX_SAMP_DBG(rssi_ctl0) = rs->rs_rssi_ctl0; - RX_SAMP_DBG(rssi_ctl1) = rs->rs_rssi_ctl1; - RX_SAMP_DBG(rssi_ctl2) = rs->rs_rssi_ctl2; - RX_SAMP_DBG(rssi_ext0) = rs->rs_rssi_ext0; - RX_SAMP_DBG(rssi_ext1) = rs->rs_rssi_ext1; - RX_SAMP_DBG(rssi_ext2) = rs->rs_rssi_ext2; - RX_SAMP_DBG(antenna) = rs->rs_antenna; - RX_SAMP_DBG(rssi) = rs->rs_rssi; - RX_SAMP_DBG(rate) = rs->rs_rate; - RX_SAMP_DBG(is_mybeacon) = rs->is_mybeacon; - - sc->debug.rsidx = (sc->debug.rsidx + 1) % ATH_DBG_MAX_SAMPLES; - spin_unlock(&sc->debug.samp_lock); - -#endif - #undef RX_PHY_ERR_INC -#undef RX_SAMP_DBG } static const struct file_operations fops_recv = { @@ -1485,283 +1430,6 @@ static const struct file_operations fops_modal_eeprom = { .llseek = default_llseek, }; -#ifdef CONFIG_ATH9K_MAC_DEBUG - -void ath9k_debug_samp_bb_mac(struct ath_softc *sc) -{ -#define ATH_SAMP_DBG(c) (sc->debug.bb_mac_samp[sc->debug.sampidx].c) - struct ath_hw *ah = sc->sc_ah; - struct ath_common *common = ath9k_hw_common(ah); - unsigned long flags; - int i; - - ath9k_ps_wakeup(sc); - - spin_lock_bh(&sc->debug.samp_lock); - - spin_lock_irqsave(&common->cc_lock, flags); - ath_hw_cycle_counters_update(common); - - ATH_SAMP_DBG(cc.cycles) = common->cc_ani.cycles; - ATH_SAMP_DBG(cc.rx_busy) = common->cc_ani.rx_busy; - ATH_SAMP_DBG(cc.rx_frame) = common->cc_ani.rx_frame; - ATH_SAMP_DBG(cc.tx_frame) = common->cc_ani.tx_frame; - spin_unlock_irqrestore(&common->cc_lock, flags); - - ATH_SAMP_DBG(noise) = ah->noise; - - REG_WRITE_D(ah, AR_MACMISC, - ((AR_MACMISC_DMA_OBS_LINE_8 << AR_MACMISC_DMA_OBS_S) | - (AR_MACMISC_MISC_OBS_BUS_1 << - AR_MACMISC_MISC_OBS_BUS_MSB_S))); - - for (i = 0; i < ATH9K_NUM_DMA_DEBUG_REGS; i++) - ATH_SAMP_DBG(dma_dbg_reg_vals[i]) = REG_READ_D(ah, - AR_DMADBG_0 + (i * sizeof(u32))); - - ATH_SAMP_DBG(pcu_obs) = REG_READ_D(ah, AR_OBS_BUS_1); - ATH_SAMP_DBG(pcu_cr) = REG_READ_D(ah, AR_CR); - - memcpy(ATH_SAMP_DBG(nfCalHist), sc->caldata.nfCalHist, - sizeof(ATH_SAMP_DBG(nfCalHist))); - - sc->debug.sampidx = (sc->debug.sampidx + 1) % ATH_DBG_MAX_SAMPLES; - spin_unlock_bh(&sc->debug.samp_lock); - ath9k_ps_restore(sc); - -#undef ATH_SAMP_DBG -} - -static int open_file_bb_mac_samps(struct inode *inode, struct file *file) -{ -#define ATH_SAMP_DBG(c) bb_mac_samp[sampidx].c - struct ath_softc *sc = inode->i_private; - struct ath_hw *ah = sc->sc_ah; - struct ath_common *common = ath9k_hw_common(ah); - struct ieee80211_conf *conf = &common->hw->conf; - struct ath_dbg_bb_mac_samp *bb_mac_samp; - struct ath9k_nfcal_hist *h; - int i, j, qcuOffset = 0, dcuOffset = 0; - u32 *qcuBase, *dcuBase, size = 30000, len = 0; - u32 sampidx = 0; - u8 *buf; - u8 chainmask = (ah->rxchainmask << 3) | ah->rxchainmask; - u8 nread; - - if (test_bit(SC_OP_INVALID, &sc->sc_flags)) - return -EAGAIN; - - buf = vmalloc(size); - if (!buf) - return -ENOMEM; - bb_mac_samp = vmalloc(sizeof(*bb_mac_samp) * ATH_DBG_MAX_SAMPLES); - if (!bb_mac_samp) { - vfree(buf); - return -ENOMEM; - } - /* Account the current state too */ - ath9k_debug_samp_bb_mac(sc); - - spin_lock_bh(&sc->debug.samp_lock); - memcpy(bb_mac_samp, sc->debug.bb_mac_samp, - sizeof(*bb_mac_samp) * ATH_DBG_MAX_SAMPLES); - len += snprintf(buf + len, size - len, - "Current Sample Index: %d\n", sc->debug.sampidx); - spin_unlock_bh(&sc->debug.samp_lock); - - len += snprintf(buf + len, size - len, - "Raw DMA Debug Dump:\n"); - len += snprintf(buf + len, size - len, "Sample |\t"); - for (i = 0; i < ATH9K_NUM_DMA_DEBUG_REGS; i++) - len += snprintf(buf + len, size - len, " DMA Reg%d |\t", i); - len += snprintf(buf + len, size - len, "\n"); - - for (sampidx = 0; sampidx < ATH_DBG_MAX_SAMPLES; sampidx++) { - len += snprintf(buf + len, size - len, "%d\t", sampidx); - - for (i = 0; i < ATH9K_NUM_DMA_DEBUG_REGS; i++) - len += snprintf(buf + len, size - len, " %08x\t", - ATH_SAMP_DBG(dma_dbg_reg_vals[i])); - len += snprintf(buf + len, size - len, "\n"); - } - len += snprintf(buf + len, size - len, "\n"); - - len += snprintf(buf + len, size - len, - "Sample Num QCU: chain_st fsp_ok fsp_st DCU: chain_st\n"); - for (sampidx = 0; sampidx < ATH_DBG_MAX_SAMPLES; sampidx++) { - qcuBase = &ATH_SAMP_DBG(dma_dbg_reg_vals[0]); - dcuBase = &ATH_SAMP_DBG(dma_dbg_reg_vals[4]); - - for (i = 0; i < ATH9K_NUM_QUEUES; i++, - qcuOffset += 4, dcuOffset += 5) { - if (i == 8) { - qcuOffset = 0; - qcuBase++; - } - - if (i == 6) { - dcuOffset = 0; - dcuBase++; - } - if (!sc->debug.stats.txstats[i].queued) - continue; - - len += snprintf(buf + len, size - len, - "%4d %7d %2x %1x %2x %2x\n", - sampidx, i, - (*qcuBase & (0x7 << qcuOffset)) >> qcuOffset, - (*qcuBase & (0x8 << qcuOffset)) >> - (qcuOffset + 3), - ATH_SAMP_DBG(dma_dbg_reg_vals[2]) & - (0x7 << (i * 3)) >> (i * 3), - (*dcuBase & (0x1f << dcuOffset)) >> dcuOffset); - } - len += snprintf(buf + len, size - len, "\n"); - } - len += snprintf(buf + len, size - len, - "samp qcu_sh qcu_fh qcu_comp dcu_comp dcu_arb dcu_fp " - "ch_idle_dur ch_idle_dur_val txfifo_val0 txfifo_val1 " - "txfifo_dcu0 txfifo_dcu1 pcu_obs AR_CR\n"); - - for (sampidx = 0; sampidx < ATH_DBG_MAX_SAMPLES; sampidx++) { - qcuBase = &ATH_SAMP_DBG(dma_dbg_reg_vals[0]); - dcuBase = &ATH_SAMP_DBG(dma_dbg_reg_vals[4]); - - len += snprintf(buf + len, size - len, "%4d %5x %5x ", sampidx, - (ATH_SAMP_DBG(dma_dbg_reg_vals[3]) & 0x003c0000) >> 18, - (ATH_SAMP_DBG(dma_dbg_reg_vals[3]) & 0x03c00000) >> 22); - len += snprintf(buf + len, size - len, "%7x %8x ", - (ATH_SAMP_DBG(dma_dbg_reg_vals[3]) & 0x1c000000) >> 26, - (ATH_SAMP_DBG(dma_dbg_reg_vals[6]) & 0x3)); - len += snprintf(buf + len, size - len, "%7x %7x ", - (ATH_SAMP_DBG(dma_dbg_reg_vals[5]) & 0x06000000) >> 25, - (ATH_SAMP_DBG(dma_dbg_reg_vals[5]) & 0x38000000) >> 27); - len += snprintf(buf + len, size - len, "%7d %12d ", - (ATH_SAMP_DBG(dma_dbg_reg_vals[6]) & 0x000003fc) >> 2, - (ATH_SAMP_DBG(dma_dbg_reg_vals[6]) & 0x00000400) >> 10); - len += snprintf(buf + len, size - len, "%12d %12d ", - (ATH_SAMP_DBG(dma_dbg_reg_vals[6]) & 0x00000800) >> 11, - (ATH_SAMP_DBG(dma_dbg_reg_vals[6]) & 0x00001000) >> 12); - len += snprintf(buf + len, size - len, "%12d %12d ", - (ATH_SAMP_DBG(dma_dbg_reg_vals[6]) & 0x0001e000) >> 13, - (ATH_SAMP_DBG(dma_dbg_reg_vals[6]) & 0x001e0000) >> 17); - len += snprintf(buf + len, size - len, "0x%07x 0x%07x\n", - ATH_SAMP_DBG(pcu_obs), ATH_SAMP_DBG(pcu_cr)); - } - - len += snprintf(buf + len, size - len, - "Sample ChNoise Chain privNF #Reading Readings\n"); - for (sampidx = 0; sampidx < ATH_DBG_MAX_SAMPLES; sampidx++) { - h = ATH_SAMP_DBG(nfCalHist); - if (!ATH_SAMP_DBG(noise)) - continue; - - for (i = 0; i < NUM_NF_READINGS; i++) { - if (!(chainmask & (1 << i)) || - ((i >= AR5416_MAX_CHAINS) && !conf_is_ht40(conf))) - continue; - - nread = AR_PHY_CCA_FILTERWINDOW_LENGTH - - h[i].invalidNFcount; - len += snprintf(buf + len, size - len, - "%4d %5d %4d\t %d\t %d\t", - sampidx, ATH_SAMP_DBG(noise), - i, h[i].privNF, nread); - for (j = 0; j < nread; j++) - len += snprintf(buf + len, size - len, - " %d", h[i].nfCalBuffer[j]); - len += snprintf(buf + len, size - len, "\n"); - } - } - len += snprintf(buf + len, size - len, "\nCycle counters:\n" - "Sample Total Rxbusy Rxframes Txframes\n"); - for (sampidx = 0; sampidx < ATH_DBG_MAX_SAMPLES; sampidx++) { - if (!ATH_SAMP_DBG(cc.cycles)) - continue; - len += snprintf(buf + len, size - len, - "%4d %08x %08x %08x %08x\n", - sampidx, ATH_SAMP_DBG(cc.cycles), - ATH_SAMP_DBG(cc.rx_busy), - ATH_SAMP_DBG(cc.rx_frame), - ATH_SAMP_DBG(cc.tx_frame)); - } - - len += snprintf(buf + len, size - len, "Tx status Dump :\n"); - len += snprintf(buf + len, size - len, - "Sample rssi:- ctl0 ctl1 ctl2 ext0 ext1 ext2 comb " - "isok rts_fail data_fail rate tid qid " - "ba_low ba_high tx_before(ms)\n"); - for (sampidx = 0; sampidx < ATH_DBG_MAX_SAMPLES; sampidx++) { - for (i = 0; i < ATH_DBG_MAX_SAMPLES; i++) { - if (!ATH_SAMP_DBG(ts[i].jiffies)) - continue; - len += snprintf(buf + len, size - len, "%-14d" - "%-4d %-4d %-4d %-4d %-4d %-4d %-4d %-4d %-8d " - "%-9d %-4d %-3d %-3d %08x %08x %-11d\n", - sampidx, - ATH_SAMP_DBG(ts[i].rssi_ctl0), - ATH_SAMP_DBG(ts[i].rssi_ctl1), - ATH_SAMP_DBG(ts[i].rssi_ctl2), - ATH_SAMP_DBG(ts[i].rssi_ext0), - ATH_SAMP_DBG(ts[i].rssi_ext1), - ATH_SAMP_DBG(ts[i].rssi_ext2), - ATH_SAMP_DBG(ts[i].rssi), - ATH_SAMP_DBG(ts[i].isok), - ATH_SAMP_DBG(ts[i].rts_fail_cnt), - ATH_SAMP_DBG(ts[i].data_fail_cnt), - ATH_SAMP_DBG(ts[i].rateindex), - ATH_SAMP_DBG(ts[i].tid), - ATH_SAMP_DBG(ts[i].qid), - ATH_SAMP_DBG(ts[i].ba_low), - ATH_SAMP_DBG(ts[i].ba_high), - jiffies_to_msecs(jiffies - - ATH_SAMP_DBG(ts[i].jiffies))); - } - } - - len += snprintf(buf + len, size - len, "Rx status Dump :\n"); - len += snprintf(buf + len, size - len, "Sample rssi:- ctl0 ctl1 ctl2 " - "ext0 ext1 ext2 comb beacon ant rate rx_before(ms)\n"); - for (sampidx = 0; sampidx < ATH_DBG_MAX_SAMPLES; sampidx++) { - for (i = 0; i < ATH_DBG_MAX_SAMPLES; i++) { - if (!ATH_SAMP_DBG(rs[i].jiffies)) - continue; - len += snprintf(buf + len, size - len, "%-14d" - "%-4d %-4d %-4d %-4d %-4d %-4d %-4d %-9s %-2d %02x %-13d\n", - sampidx, - ATH_SAMP_DBG(rs[i].rssi_ctl0), - ATH_SAMP_DBG(rs[i].rssi_ctl1), - ATH_SAMP_DBG(rs[i].rssi_ctl2), - ATH_SAMP_DBG(rs[i].rssi_ext0), - ATH_SAMP_DBG(rs[i].rssi_ext1), - ATH_SAMP_DBG(rs[i].rssi_ext2), - ATH_SAMP_DBG(rs[i].rssi), - ATH_SAMP_DBG(rs[i].is_mybeacon) ? - "True" : "False", - ATH_SAMP_DBG(rs[i].antenna), - ATH_SAMP_DBG(rs[i].rate), - jiffies_to_msecs(jiffies - - ATH_SAMP_DBG(rs[i].jiffies))); - } - } - - vfree(bb_mac_samp); - file->private_data = buf; - - return 0; -#undef ATH_SAMP_DBG -} - -static const struct file_operations fops_samps = { - .open = open_file_bb_mac_samps, - .read = ath9k_debugfs_read_buf, - .release = ath9k_debugfs_release_buf, - .owner = THIS_MODULE, - .llseek = default_llseek, -}; - -#endif - #ifdef CONFIG_ATH9K_BTCOEX_SUPPORT static ssize_t read_file_btcoex(struct file *file, char __user *user_buf, size_t count, loff_t *ppos) @@ -2087,11 +1755,6 @@ int ath9k_init_debug(struct ath_hw *ah) debugfs_create_file("spectral_fft_period", S_IRUSR | S_IWUSR, sc->debug.debugfs_phy, sc, &fops_spectral_fft_period); - -#ifdef CONFIG_ATH9K_MAC_DEBUG - debugfs_create_file("samples", S_IRUSR, sc->debug.debugfs_phy, sc, - &fops_samps); -#endif debugfs_create_u32("gpio_mask", S_IRUSR | S_IWUSR, sc->debug.debugfs_phy, &sc->sc_ah->gpio_mask); debugfs_create_u32("gpio_val", S_IRUSR | S_IWUSR, diff --git a/drivers/net/wireless/ath/ath9k/debug.h b/drivers/net/wireless/ath/ath9k/debug.h index 794a7ec..62da19c 100644 --- a/drivers/net/wireless/ath/ath9k/debug.h +++ b/drivers/net/wireless/ath/ath9k/debug.h @@ -294,13 +294,6 @@ struct ath9k_debug { struct dentry *debugfs_phy; u32 regidx; struct ath_stats stats; -#ifdef CONFIG_ATH9K_MAC_DEBUG - spinlock_t samp_lock; - struct ath_dbg_bb_mac_samp bb_mac_samp[ATH_DBG_MAX_SAMPLES]; - u8 sampidx; - u8 tsidx; - u8 rsidx; -#endif }; int ath9k_init_debug(struct ath_hw *ah); @@ -359,17 +352,4 @@ static inline void ath_debug_stat_rx(struct ath_softc *sc, #endif /* CONFIG_ATH9K_DEBUGFS */ -#ifdef CONFIG_ATH9K_MAC_DEBUG - -void ath9k_debug_samp_bb_mac(struct ath_softc *sc); - -#else - -static inline void ath9k_debug_samp_bb_mac(struct ath_softc *sc) -{ -} - -#endif - - #endif /* DEBUG_H */ diff --git a/drivers/net/wireless/ath/ath9k/init.c b/drivers/net/wireless/ath/ath9k/init.c index 0237b28..c7b888f 100644 --- a/drivers/net/wireless/ath/ath9k/init.c +++ b/drivers/net/wireless/ath/ath9k/init.c @@ -613,9 +613,6 @@ static int ath9k_init_softc(u16 devid, struct ath_softc *sc, spin_lock_init(&sc->sc_serial_rw); spin_lock_init(&sc->sc_pm_lock); mutex_init(&sc->mutex); -#ifdef CONFIG_ATH9K_MAC_DEBUG - spin_lock_init(&sc->debug.samp_lock); -#endif tasklet_init(&sc->intr_tq, ath9k_tasklet, (unsigned long)sc); tasklet_init(&sc->bcon_tasklet, ath9k_beacon_tasklet, (unsigned long)sc); diff --git a/drivers/net/wireless/ath/ath9k/link.c b/drivers/net/wireless/ath/ath9k/link.c index 849259b..cc422a4 100644 --- a/drivers/net/wireless/ath/ath9k/link.c +++ b/drivers/net/wireless/ath/ath9k/link.c @@ -418,7 +418,6 @@ void ath_ani_calibrate(unsigned long data) longcal ? "long" : "", shortcal ? "short" : "", aniflag ? "ani" : "", common->ani.caldone ? "true" : "false"); - ath9k_debug_samp_bb_mac(sc); ath9k_ps_restore(sc); set_timer: diff --git a/drivers/net/wireless/ath/ath9k/main.c b/drivers/net/wireless/ath/ath9k/main.c index a18414b..04bf88a 100644 --- a/drivers/net/wireless/ath/ath9k/main.c +++ b/drivers/net/wireless/ath/ath9k/main.c @@ -193,7 +193,6 @@ static bool ath_prepare_reset(struct ath_softc *sc) ath_stop_ani(sc); del_timer_sync(&sc->rx_poll_timer); - ath9k_debug_samp_bb_mac(sc); ath9k_hw_disable_interrupts(ah); if (!ath_drain_all_txq(sc)) -- 1.8.2.2 -- 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