From patchwork Mon May 23 14:20:09 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Jander X-Patchwork-Id: 12859127 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6CB95C433F5 for ; Mon, 23 May 2022 14:20:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237092AbiEWOUt (ORCPT ); Mon, 23 May 2022 10:20:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47238 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237086AbiEWOUr (ORCPT ); Mon, 23 May 2022 10:20:47 -0400 Received: from smtp15.bhosted.nl (smtp15.bhosted.nl [IPv6:2a02:9e0:8000::26]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 718155A154 for ; Mon, 23 May 2022 07:20:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=protonic.nl; s=202111; h=content-transfer-encoding:mime-version:message-id:date:subject:cc:to:from: from; bh=kanlj5TL7hyZO0+VkKKM1pgI5taN89brq3sa0OlmWKk=; b=lO5yyArUTVigyYvT2qi2hcIwIoPnjglSIuBF0UMAOVdZcyMRD0wRwagMgSWSoKT18ZdZ9VKn/S4Ld Tei4VKTcPDImpFe0H8nL4trZ+gihPchqn2JcIZgMV8IACkxBHFWH59f03CywsWM6kMSwwTCmXqYbrq rH0pHWAZvMUGAgHni4gi2oi3cj4m7/7dEpVJTfp4yAb0RF9KdfwvivGvXkvdxsfU6cTDttLM83MNIw 2TeugmGObTpVBubvaWmoTBr9KR4szkNTnGk4gY1hDRylXPXg/x4jTC7++fA7bDGXwS1SivaCPysBS0 n1Us4fC/OZpFiJQJ7tKwTRD2kkHwhLQ== X-MSG-ID: 864f16a4-daa3-11ec-b450-0050569d3a82 From: David Jander To: Mark Brown Cc: linux-spi@vger.kernel.org, Andrew Lunn , Marc Kleine-Budde , David Jander Subject: [PATCH] drivers: spi: spi.c: Convert statistics to per-cpu u64_stats_t Date: Mon, 23 May 2022 16:20:09 +0200 Message-Id: <20220523142009.2218738-1-david@protonic.nl> X-Mailer: git-send-email 2.32.0 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-spi@vger.kernel.org This change gives a dramatic performance improvement in the hot path, since many costly spin_lock_irqsave() calls can be avoided. Suggested-by: Andrew Lunn Signed-off-by: David Jander --- drivers/spi/spi.c | 95 ++++++++++++++++++++++++----------------- include/linux/spi/spi.h | 80 ++++++++++++++++++++++++---------- 2 files changed, 114 insertions(+), 61 deletions(-) diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index c4dd1200fe99..edc290e67b92 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -33,6 +33,7 @@ #include #include #include +#include #define CREATE_TRACE_POINTS #include @@ -111,6 +112,25 @@ static ssize_t driver_override_show(struct device *dev, } static DEVICE_ATTR_RW(driver_override); +#define spi_pcpu_stats_totalize(ret, in, field) \ +do { \ + int i; \ + ret = 0; \ + for_each_possible_cpu(i) { \ + const struct spi_statistics *pcpu_stats; \ + u64 inc; \ + unsigned int start; \ + pcpu_stats = per_cpu_ptr(in, i); \ + do { \ + start = u64_stats_fetch_begin_irq( \ + &pcpu_stats->syncp); \ + inc = u64_stats_read(&pcpu_stats->field); \ + } while (u64_stats_fetch_retry_irq( \ + &pcpu_stats->syncp, start)); \ + ret += inc; \ + } \ +} while (0) + #define SPI_STATISTICS_ATTRS(field, file) \ static ssize_t spi_controller_##field##_show(struct device *dev, \ struct device_attribute *attr, \ @@ -118,7 +138,7 @@ static ssize_t spi_controller_##field##_show(struct device *dev, \ { \ struct spi_controller *ctlr = container_of(dev, \ struct spi_controller, dev); \ - return spi_statistics_##field##_show(&ctlr->statistics, buf); \ + return spi_statistics_##field##_show(ctlr->pcpu_statistics, buf); \ } \ static struct device_attribute dev_attr_spi_controller_##field = { \ .attr = { .name = file, .mode = 0444 }, \ @@ -129,7 +149,7 @@ static ssize_t spi_device_##field##_show(struct device *dev, \ char *buf) \ { \ struct spi_device *spi = to_spi_device(dev); \ - return spi_statistics_##field##_show(&spi->statistics, buf); \ + return spi_statistics_##field##_show(spi->pcpu_statistics, buf); \ } \ static struct device_attribute dev_attr_spi_device_##field = { \ .attr = { .name = file, .mode = 0444 }, \ @@ -140,11 +160,10 @@ static struct device_attribute dev_attr_spi_device_##field = { \ static ssize_t spi_statistics_##name##_show(struct spi_statistics *stat, \ char *buf) \ { \ - unsigned long flags; \ ssize_t len; \ - spin_lock_irqsave(&stat->lock, flags); \ - len = sysfs_emit(buf, format_string "\n", stat->field); \ - spin_unlock_irqrestore(&stat->lock, flags); \ + u64 val; \ + spi_pcpu_stats_totalize(val, stat, field); \ + len = sysfs_emit(buf, format_string "\n", val); \ return len; \ } \ SPI_STATISTICS_ATTRS(name, file) @@ -153,14 +172,14 @@ SPI_STATISTICS_ATTRS(name, file) SPI_STATISTICS_SHOW_NAME(field, __stringify(field), \ field, format_string) -SPI_STATISTICS_SHOW(messages, "%lu"); -SPI_STATISTICS_SHOW(transfers, "%lu"); -SPI_STATISTICS_SHOW(errors, "%lu"); -SPI_STATISTICS_SHOW(timedout, "%lu"); +SPI_STATISTICS_SHOW(messages, "%llu"); +SPI_STATISTICS_SHOW(transfers, "%llu"); +SPI_STATISTICS_SHOW(errors, "%llu"); +SPI_STATISTICS_SHOW(timedout, "%llu"); -SPI_STATISTICS_SHOW(spi_sync, "%lu"); -SPI_STATISTICS_SHOW(spi_sync_immediate, "%lu"); -SPI_STATISTICS_SHOW(spi_async, "%lu"); +SPI_STATISTICS_SHOW(spi_sync, "%llu"); +SPI_STATISTICS_SHOW(spi_sync_immediate, "%llu"); +SPI_STATISTICS_SHOW(spi_async, "%llu"); SPI_STATISTICS_SHOW(bytes, "%llu"); SPI_STATISTICS_SHOW(bytes_rx, "%llu"); @@ -169,7 +188,7 @@ SPI_STATISTICS_SHOW(bytes_tx, "%llu"); #define SPI_STATISTICS_TRANSFER_BYTES_HISTO(index, number) \ SPI_STATISTICS_SHOW_NAME(transfer_bytes_histo##index, \ "transfer_bytes_histo_" number, \ - transfer_bytes_histo[index], "%lu") + transfer_bytes_histo[index], "%llu") SPI_STATISTICS_TRANSFER_BYTES_HISTO(0, "0-1"); SPI_STATISTICS_TRANSFER_BYTES_HISTO(1, "2-3"); SPI_STATISTICS_TRANSFER_BYTES_HISTO(2, "4-7"); @@ -188,7 +207,7 @@ SPI_STATISTICS_TRANSFER_BYTES_HISTO(14, "16384-32767"); SPI_STATISTICS_TRANSFER_BYTES_HISTO(15, "32768-65535"); SPI_STATISTICS_TRANSFER_BYTES_HISTO(16, "65536+"); -SPI_STATISTICS_SHOW(transfers_split_maxsize, "%lu"); +SPI_STATISTICS_SHOW(transfers_split_maxsize, "%llu"); static struct attribute *spi_dev_attrs[] = { &dev_attr_modalias.attr, @@ -285,30 +304,30 @@ static const struct attribute_group *spi_master_groups[] = { NULL, }; -static void spi_statistics_add_transfer_stats(struct spi_statistics *stats, +static void spi_statistics_add_transfer_stats(struct spi_statistics *pcpu_stats, struct spi_transfer *xfer, struct spi_controller *ctlr) { - unsigned long flags; int l2len = min(fls(xfer->len), SPI_STATISTICS_HISTO_SIZE) - 1; + struct spi_statistics *stats = this_cpu_ptr(pcpu_stats); if (l2len < 0) l2len = 0; - spin_lock_irqsave(&stats->lock, flags); + u64_stats_update_begin(&stats->syncp); - stats->transfers++; - stats->transfer_bytes_histo[l2len]++; + u64_stats_inc(&stats->transfers); + u64_stats_inc(&stats->transfer_bytes_histo[l2len]); - stats->bytes += xfer->len; + u64_stats_add(&stats->bytes, xfer->len); if ((xfer->tx_buf) && (xfer->tx_buf != ctlr->dummy_tx)) - stats->bytes_tx += xfer->len; + u64_stats_add(&stats->bytes_tx, xfer->len); if ((xfer->rx_buf) && (xfer->rx_buf != ctlr->dummy_rx)) - stats->bytes_rx += xfer->len; + u64_stats_add(&stats->bytes_rx, xfer->len); - spin_unlock_irqrestore(&stats->lock, flags); + u64_stats_update_end(&stats->syncp); } /* @@ -543,7 +562,7 @@ struct spi_device *spi_alloc_device(struct spi_controller *ctlr) spi->dev.release = spidev_release; spi->mode = ctlr->buswidth_override_bits; - spin_lock_init(&spi->statistics.lock); + spi->pcpu_statistics = spi_alloc_pcpu_stats(struct spi_statistics); device_initialize(&spi->dev); return spi; @@ -1239,8 +1258,8 @@ static int spi_transfer_wait(struct spi_controller *ctlr, struct spi_message *msg, struct spi_transfer *xfer) { - struct spi_statistics *statm = &ctlr->statistics; - struct spi_statistics *stats = &msg->spi->statistics; + struct spi_statistics *statm = ctlr->pcpu_statistics; + struct spi_statistics *stats = msg->spi->pcpu_statistics; u32 speed_hz = xfer->speed_hz; unsigned long long ms; @@ -1396,8 +1415,8 @@ static int spi_transfer_one_message(struct spi_controller *ctlr, struct spi_transfer *xfer; bool keep_cs = false; int ret = 0; - struct spi_statistics *statm = &ctlr->statistics; - struct spi_statistics *stats = &msg->spi->statistics; + struct spi_statistics *statm = ctlr->pcpu_statistics; + struct spi_statistics *stats = msg->spi->pcpu_statistics; spi_set_cs(msg->spi, true, false); @@ -3042,7 +3061,7 @@ int spi_register_controller(struct spi_controller *ctlr) } } /* add statistics */ - spin_lock_init(&ctlr->statistics.lock); + ctlr->pcpu_statistics = devm_spi_alloc_pcpu_stats(dev, struct spi_statistics); mutex_lock(&board_lock); list_add_tail(&ctlr->list, &spi_controller_list); @@ -3380,9 +3399,9 @@ static int __spi_split_transfer_maxsize(struct spi_controller *ctlr, *xferp = &xfers[count - 1]; /* increment statistics counters */ - SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics, + SPI_STATISTICS_INCREMENT_FIELD(ctlr->pcpu_statistics, transfers_split_maxsize); - SPI_STATISTICS_INCREMENT_FIELD(&msg->spi->statistics, + SPI_STATISTICS_INCREMENT_FIELD(msg->spi->pcpu_statistics, transfers_split_maxsize); return 0; @@ -3769,8 +3788,8 @@ static int __spi_async(struct spi_device *spi, struct spi_message *message) message->spi = spi; - SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics, spi_async); - SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_async); + SPI_STATISTICS_INCREMENT_FIELD(ctlr->pcpu_statistics, spi_async); + SPI_STATISTICS_INCREMENT_FIELD(spi->pcpu_statistics, spi_async); trace_spi_message_submit(message); @@ -3917,8 +3936,8 @@ static int __spi_sync(struct spi_device *spi, struct spi_message *message) message->context = &done; message->spi = spi; - SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics, spi_sync); - SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, spi_sync); + SPI_STATISTICS_INCREMENT_FIELD(ctlr->pcpu_statistics, spi_sync); + SPI_STATISTICS_INCREMENT_FIELD(spi->pcpu_statistics, spi_sync); /* * If we're not using the legacy transfer method then we will @@ -3941,9 +3960,9 @@ static int __spi_sync(struct spi_device *spi, struct spi_message *message) if (status == 0) { /* Push out the messages in the calling context if we can */ if (ctlr->transfer == spi_queued_transfer) { - SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics, + SPI_STATISTICS_INCREMENT_FIELD(ctlr->pcpu_statistics, spi_sync_immediate); - SPI_STATISTICS_INCREMENT_FIELD(&spi->statistics, + SPI_STATISTICS_INCREMENT_FIELD(spi->pcpu_statistics, spi_sync_immediate); __spi_pump_messages(ctlr, false); } diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h index 5f8c063ddff4..ea7f802f5a79 100644 --- a/include/linux/spi/spi.h +++ b/include/linux/spi/spi.h @@ -17,6 +17,7 @@ #include #include +#include struct dma_chan; struct software_node; @@ -59,37 +60,70 @@ extern struct bus_type spi_bus_type; * maxsize limit */ struct spi_statistics { - spinlock_t lock; /* lock for the whole structure */ + struct u64_stats_sync syncp; - unsigned long messages; - unsigned long transfers; - unsigned long errors; - unsigned long timedout; + u64_stats_t messages; + u64_stats_t transfers; + u64_stats_t errors; + u64_stats_t timedout; - unsigned long spi_sync; - unsigned long spi_sync_immediate; - unsigned long spi_async; + u64_stats_t spi_sync; + u64_stats_t spi_sync_immediate; + u64_stats_t spi_async; - unsigned long long bytes; - unsigned long long bytes_rx; - unsigned long long bytes_tx; + u64_stats_t bytes; + u64_stats_t bytes_rx; + u64_stats_t bytes_tx; #define SPI_STATISTICS_HISTO_SIZE 17 - unsigned long transfer_bytes_histo[SPI_STATISTICS_HISTO_SIZE]; + u64_stats_t transfer_bytes_histo[SPI_STATISTICS_HISTO_SIZE]; - unsigned long transfers_split_maxsize; + u64_stats_t transfers_split_maxsize; }; -#define SPI_STATISTICS_ADD_TO_FIELD(stats, field, count) \ - do { \ - unsigned long flags; \ - spin_lock_irqsave(&(stats)->lock, flags); \ - (stats)->field += count; \ - spin_unlock_irqrestore(&(stats)->lock, flags); \ +#define SPI_STATISTICS_ADD_TO_FIELD(pcpu_stats, field, count) \ + do { \ + struct spi_statistics *__lstats = this_cpu_ptr(pcpu_stats); \ + u64_stats_update_begin(&__lstats->syncp); \ + u64_stats_add(&__lstats->field, count); \ + u64_stats_update_end(&__lstats->syncp); \ } while (0) -#define SPI_STATISTICS_INCREMENT_FIELD(stats, field) \ - SPI_STATISTICS_ADD_TO_FIELD(stats, field, 1) +#define SPI_STATISTICS_INCREMENT_FIELD(pcpu_stats, field) \ + do { \ + struct spi_statistics *__lstats = this_cpu_ptr(pcpu_stats); \ + u64_stats_update_begin(&__lstats->syncp); \ + u64_stats_inc(&__lstats->field); \ + u64_stats_update_end(&__lstats->syncp); \ + } while (0) + +#define devm_spi_alloc_pcpu_stats(dev, type) \ +({ \ + typeof(type) __percpu *pcpu_stats = devm_alloc_percpu(dev, type);\ + if (pcpu_stats) { \ + int __cpu; \ + for_each_possible_cpu(__cpu) { \ + typeof(type) *stat; \ + stat = per_cpu_ptr(pcpu_stats, __cpu); \ + u64_stats_init(&stat->syncp); \ + } \ + } \ + pcpu_stats; \ +}) + +#define spi_alloc_pcpu_stats(type) \ +({ \ + typeof(type) __percpu *pcpu_stats = alloc_percpu_gfp(type, GFP_KERNEL);\ + if (pcpu_stats) { \ + int __cpu; \ + for_each_possible_cpu(__cpu) { \ + typeof(type) *stat; \ + stat = per_cpu_ptr(pcpu_stats, __cpu); \ + u64_stats_init(&stat->syncp); \ + } \ + } \ + pcpu_stats; \ +}) /** * struct spi_delay - SPI delay information @@ -192,7 +226,7 @@ struct spi_device { struct spi_delay cs_inactive; /* the statistics */ - struct spi_statistics statistics; + struct spi_statistics __percpu *pcpu_statistics; /* * likely need more hooks for more protocol options affecting how @@ -643,7 +677,7 @@ struct spi_controller { s8 max_native_cs; /* statistics */ - struct spi_statistics statistics; + struct spi_statistics __percpu *pcpu_statistics; /* DMA channels for use with core dmaengine helpers */ struct dma_chan *dma_tx;