From patchwork Thu Jun 3 01:12:23 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Douglas Gilbert X-Patchwork-Id: 12295961 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 068C2C4708F for ; Thu, 3 Jun 2021 01:12:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D442B613DC for ; Thu, 3 Jun 2021 01:12:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229707AbhFCBOW (ORCPT ); Wed, 2 Jun 2021 21:14:22 -0400 Received: from smtp.infotech.no ([82.134.31.41]:55356 "EHLO smtp.infotech.no" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229553AbhFCBOV (ORCPT ); Wed, 2 Jun 2021 21:14:21 -0400 Received: from localhost (localhost [127.0.0.1]) by smtp.infotech.no (Postfix) with ESMTP id 1E3292041AC; Thu, 3 Jun 2021 03:12:36 +0200 (CEST) X-Virus-Scanned: by amavisd-new-2.6.6 (20110518) (Debian) at infotech.no Received: from smtp.infotech.no ([127.0.0.1]) by localhost (smtp.infotech.no [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id jLlrHWkGnQC7; Thu, 3 Jun 2021 03:12:26 +0200 (CEST) Received: from xtwo70.bingwo.ca (host-45-58-219-4.dyn.295.ca [45.58.219.4]) by smtp.infotech.no (Postfix) with ESMTPA id DEF54204179; Thu, 3 Jun 2021 03:12:25 +0200 (CEST) From: Douglas Gilbert To: linux-scsi@vger.kernel.org Cc: martin.petersen@oracle.com, Damien.LeMoal@wdc.com, sysstat@orange.fr, hare@suse.de Subject: [RFC] sg: add statistics similar to st Date: Wed, 2 Jun 2021 21:12:23 -0400 Message-Id: <20210603011223.390826-1-dgilbert@interlog.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org Using the existing statistics gathering framework from the st driver, collect statistics for access via sysfs. The sysstat package already has a utility called tapestat for presenting st statistics. Its author is keen to use the existing tapestat code for showing sg statistics (rather than write a new utility). In keeping with the sg driver being SCSI command agnostic, the "read" statistics are compiled for requests that have "data-in" user data while write statistics are compiled for requests that have "data-out" user data. A new module/driver load time parameter called "no_stats" has been added. It is boolean, the default is to collect statistics. Signed-off-by: Douglas Gilbert --- This patch is based on my patchset whose cover is titled: "[PATCH v19 00/45] sg: add v4 interface" sent to the linux-scsi list on 20210523. That patchset is against Martin Petersen's 5.14/scsi-queue branch. drivers/scsi/sg.c | 259 ++++++++++++++++++++++++++++++++++++++++------ 1 file changed, 227 insertions(+), 32 deletions(-) diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c index d47efed3a3ca..eedeeb1872f7 100644 --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -143,6 +143,7 @@ int sg_big_buff = SG_DEF_RESERVED_SIZE; */ static int def_reserved_size = -1; /* picks up init parameter */ static int sg_allow_dio = SG_ALLOW_DIO_DEF; /* ignored by code */ +static bool sg_no_stats; static int scatter_elem_sz = SG_SCATTER_SZ; @@ -213,7 +214,7 @@ struct sg_request { /* active SCSI command or inactive request */ atomic_t rq_st; /* request state, holds a enum sg_rq_state */ u8 cmd_opcode; /* first byte of SCSI cdb */ blk_qc_t cookie; /* ids 1 or more queues for blk_poll() */ - u64 start_ns; /* starting point of command duration calc */ + ktime_t start_dur; /* start time if before completion */ unsigned long frq_bm[1]; /* see SG_FRQ_* defines above */ u8 *sense_bp; /* mempool alloc-ed sense buffer, as needed */ struct sg_fd *parentfp; /* pointer to owning fd, even when on fl */ @@ -258,6 +259,7 @@ struct sg_device { /* holds the state of each scsi generic device */ unsigned long fdev_bm[1]; /* see SG_FDEV_* defines above */ struct gendisk *disk; struct cdev *cdev; + struct sg_dev_stats *statsp; /* NULL when no_stats=true */ struct xarray sfp_arr; struct kref d_ref; }; @@ -275,6 +277,19 @@ struct sg_comm_wr_t { /* arguments to sg_common_write() */ const u8 __user *u_cmdp; }; +struct sg_dev_stats { /* copied from drivers/scsi/st.h scsi_tape_stats */ + atomic64_t read_byte_cnt; /* data-in bytes */ + atomic64_t write_byte_cnt; /* data-out bytes */ + atomic64_t in_flight; /* Number of I/Os in flight */ + atomic64_t read_cnt; /* Count of data-in requests */ + atomic64_t write_cnt; /* Count of data-out requests */ + atomic64_t other_cnt; /* Count of non-data requests */ + atomic64_t resid_cnt; /* Count of resid_len > 0 */ + atomic64_t tot_read_time; /* time spent completing data-in_s */ + atomic64_t tot_write_time; /* time spent completing data-out_s */ + atomic64_t tot_io_time; /* ktime spent doing any I/O */ +}; + /* tasklet or soft irq callback */ static void sg_rq_end_io(struct request *rq, blk_status_t status); /* Declarations of other static functions used before they are defined */ @@ -306,6 +321,8 @@ static struct sg_request *sg_mk_srp_sgat(struct sg_fd *sfp, bool first, static int sg_sfp_blk_poll(struct sg_fd *sfp, int loop_count); static int sg_srp_q_blk_poll(struct sg_request *srp, struct request_queue *q, int loop_count); +static u32 sg_get_dur(struct sg_request *srp, const enum sg_rq_state *sr_stp, + bool *is_durp); #if IS_ENABLED(CONFIG_SCSI_LOGGING) && IS_ENABLED(SG_DEBUG) static const char *sg_rq_st_str(enum sg_rq_state rq_st, bool long_str); #endif @@ -1020,7 +1037,12 @@ sg_execute_cmd(struct sg_fd *sfp, struct sg_request *srp) is_v4h = test_bit(SG_FRQ_IS_V4I, srp->frq_bm); sync = test_bit(SG_FRQ_SYNC_INVOC, srp->frq_bm); SG_LOG(3, sfp, "%s: is_v4h=%d\n", __func__, (int)is_v4h); - srp->start_ns = ktime_get_boottime_ns(); + if (sg_no_stats) { + WRITE_ONCE(srp->start_dur, 0); + } else { + atomic64_inc(&sdp->statsp->in_flight); + WRITE_ONCE(srp->start_dur, ktime_get_boottime()); + } srp->duration = 0; if (!is_v4h && srp->s_hdr3.interface_id == '\0') @@ -1194,11 +1216,45 @@ sg_copy_sense(struct sg_request *srp, bool v4_active) return sb_len_ret; } +static void +sg_do_stats(struct sg_fd *sfp, struct sg_request *srp, bool v4_active) +{ + int dir = v4_active ? srp->s_hdr4.dir : srp->s_hdr3.dxfer_direction; + ktime_t kt = READ_ONCE(srp->start_dur); + struct sg_dev_stats *statsp = sfp->parentdp->statsp; + + if (!statsp) + return; + if (dir == SG_DXFER_TO_DEV) { /* data-out, write-like */ + atomic64_add(ktime_to_ns(kt), &statsp->tot_write_time); + atomic64_add(ktime_to_ns(kt), &statsp->tot_io_time); + atomic64_inc(&statsp->write_cnt); + atomic64_add(srp->sgat_h.dlen, &statsp->write_byte_cnt); + } else if (dir == SG_DXFER_FROM_DEV) { /* data-in, read-like */ + atomic64_add(ktime_to_ns(kt), &statsp->tot_read_time); + atomic64_add(ktime_to_ns(kt), &statsp->tot_io_time); + atomic64_inc(&statsp->read_cnt); + atomic64_add(srp->sgat_h.dlen, &statsp->read_byte_cnt); + if (srp->in_resid > 0) + atomic64_inc(&statsp->resid_cnt); + } else { /* no data transfer (e.g. TEST UNIT READY) */ + atomic64_add(ktime_to_ns(kt), &statsp->tot_io_time); + atomic64_inc(&statsp->other_cnt); + } + atomic64_dec(&statsp->in_flight); +} + static int sg_rec_state_v3v4(struct sg_fd *sfp, struct sg_request *srp, bool v4_active) { u32 rq_res = srp->rq_result; + if (!sg_no_stats) { + const enum sg_rq_state sr_st = SG_RS_BUSY; + + sg_do_stats(sfp, srp, v4_active); + srp->duration = sg_get_dur(srp, &sr_st, NULL); + } if (unlikely(srp->rq_result & 0xff)) { int sb_len_wr = sg_copy_sense(srp, v4_active); @@ -1625,49 +1681,43 @@ sg_calc_sgat_param(struct sg_device *sdp) sdp->max_sgat_sz = sz; } -static u32 -sg_calc_rq_dur(const struct sg_request *srp) -{ - ktime_t ts0 = ns_to_ktime(srp->start_ns); - ktime_t now_ts; - s64 diff; - - if (ts0 == 0) - return 0; - if (unlikely(ts0 == S64_MAX)) /* _prior_ to issuing req */ - return 999999999; /* eye catching */ - now_ts = ktime_get_boottime(); - if (unlikely(ts0 > now_ts)) - return 999999998; - /* unlikely req duration will exceed 2**32 milliseconds */ - diff = ktime_ms_delta(now_ts, ts0); - return (diff > (s64)U32_MAX) ? 3999999999U : (u32)diff; -} - -/* Return of U32_MAX means srp is inactive state */ static u32 sg_get_dur(struct sg_request *srp, const enum sg_rq_state *sr_stp, bool *is_durp) { bool is_dur = false; - u32 res = U32_MAX; + s64 dur_ns; + ktime_t start_dur = READ_ONCE(srp->start_dur); + if (ktime_to_ns(start_dur) <= 0) { + is_dur = true; + dur_ns = 0; + goto fini; + } switch (sr_stp ? *sr_stp : atomic_read(&srp->rq_st)) { - case SG_RS_INFLIGHT: case SG_RS_BUSY: - res = sg_calc_rq_dur(srp); + if (test_bit(SG_FRQ_ISSUED, srp->frq_bm)) { + dur_ns = ktime_to_ns(start_dur); + is_dur = true; + break; + } + dur_ns = 1; + break; + case SG_RS_INFLIGHT: + dur_ns = ktime_sub(ktime_get_boottime(), start_dur); break; case SG_RS_AWAIT_RCV: case SG_RS_INACTIVE: - res = srp->duration; + dur_ns = ktime_to_ns(start_dur); is_dur = true; /* completion has occurred, timing finished */ break; - default: - break; } +fini: if (is_durp) *is_durp = is_dur; - return res; + if (dur_ns < 2) + return 999999999; /* timekeeping problem */ + return ktime_to_ms(ns_to_ktime(dur_ns)); } static void @@ -1678,8 +1728,6 @@ sg_fill_request_element(struct sg_fd *sfp, struct sg_request *srp, xa_lock_irqsave(&sfp->srp_arr, iflags); rip->duration = sg_get_dur(srp, NULL, NULL); - if (rip->duration == U32_MAX) - rip->duration = 0; rip->orphan = test_bit(SG_FRQ_IS_ORPHAN, srp->frq_bm); rip->sg_io_owned = test_bit(SG_FRQ_SYNC_INVOC, srp->frq_bm); rip->problem = !!(srp->rq_result & SG_ML_RESULT_MSK); @@ -2502,6 +2550,7 @@ sg_rq_end_io(struct request *rqq, blk_status_t status) int a_resid, slen; u32 rq_result; unsigned long iflags; + ktime_t start_tm; struct sg_request *srp = rqq->end_io_data; struct scsi_request *scsi_rp = scsi_req(rqq); struct sg_device *sdp; @@ -2528,7 +2577,9 @@ sg_rq_end_io(struct request *rqq, blk_status_t status) SG_LOG(6, sfp, "%s: pack_id=%d, res=0x%x\n", __func__, srp->pack_id, rq_result); - srp->duration = sg_calc_rq_dur(srp); + start_tm = READ_ONCE(srp->start_dur); + if (start_tm > 0) + WRITE_ONCE(srp->start_dur, ktime_sub(ktime_get_boottime(), start_tm)); if (unlikely((rq_result & SG_ML_RESULT_MSK) && slen > 0 && test_bit(SG_FDEV_LOG_SENSE, sdp->fdev_bm))) { u32 scsi_stat = rq_result & 0xff; @@ -2683,6 +2734,8 @@ sg_add_device_helper(struct gendisk *disk, struct scsi_device *scsidp) return sdp; } +static const struct attribute_group *sg_dev_groups[]; + static int sg_add_device(struct device *cl_dev, struct class_interface *cl_intf) { @@ -2714,6 +2767,9 @@ sg_add_device(struct device *cl_dev, struct class_interface *cl_intf) error = PTR_ERR(sdp); goto out; } + if (!sg_no_stats) + sdp->statsp = kzalloc(sizeof(*sdp->statsp), GFP_KERNEL); + /* don't worry if NULL, probably a lot of devices */ error = cdev_add(cdev, MKDEV(SCSI_GENERIC_MAJOR, sdp->index), 1); if (error) @@ -2723,6 +2779,7 @@ sg_add_device(struct device *cl_dev, struct class_interface *cl_intf) if (sg_sysfs_valid) { struct device *sg_class_member; + sg_sysfs_class->dev_groups = sg_dev_groups; sg_class_member = device_create(sg_sysfs_class, cl_dev->parent, MKDEV(SCSI_GENERIC_MAJOR, sdp->index), @@ -2749,6 +2806,7 @@ sg_add_device(struct device *cl_dev, struct class_interface *cl_intf) return 0; cdev_add_err: + kfree(sdp->statsp); write_lock_irqsave(&sg_index_lock, iflags); idr_remove(&sg_index_idr, sdp->index); write_unlock_irqrestore(&sg_index_lock, iflags); @@ -2777,6 +2835,7 @@ sg_device_destroy(struct kref *kref) */ xa_destroy(&sdp->sfp_arr); + kfree(sdp->statsp); write_lock_irqsave(&sg_index_lock, flags); idr_remove(&sg_index_idr, sdp->index); write_unlock_irqrestore(&sg_index_lock, flags); @@ -3919,6 +3978,140 @@ sg_rq_st_str(enum sg_rq_state rq_st, bool long_str) } #endif +static ssize_t read_cnt_show(struct device *dev, struct device_attribute *attr, char *buf) +{ + struct sg_device *sdp = dev_get_drvdata(dev); + struct sg_dev_stats *sp = sdp->statsp; + + if (!sdp || !sp) + return -EINVAL; + return scnprintf(buf, PAGE_SIZE, "%lld\n", (long long)atomic64_read(&sp->read_cnt)); +} +static DEVICE_ATTR_RO(read_cnt); + +static ssize_t read_byte_cnt_show(struct device *dev, struct device_attribute *attr, char *buf) +{ + struct sg_device *sdp = dev_get_drvdata(dev); + struct sg_dev_stats *sp = sdp->statsp; + + if (!sdp || !sp) + return -EINVAL; + return scnprintf(buf, PAGE_SIZE, "%lld\n", (long long)atomic64_read(&sp->read_byte_cnt)); +} +static DEVICE_ATTR_RO(read_byte_cnt); + +static ssize_t read_ns_show(struct device *dev, struct device_attribute *attr, char *buf) +{ + struct sg_device *sdp = dev_get_drvdata(dev); + struct sg_dev_stats *sp = sdp->statsp; + + if (!sdp || !sp) + return -EINVAL; + return scnprintf(buf, PAGE_SIZE, "%lld\n", (long long)atomic64_read(&sp->tot_read_time)); +} +static DEVICE_ATTR_RO(read_ns); + +static ssize_t write_cnt_show(struct device *dev, struct device_attribute *attr, char *buf) +{ + struct sg_device *sdp = dev_get_drvdata(dev); + struct sg_dev_stats *sp = sdp->statsp; + + if (!sdp || !sp) + return -EINVAL; + return scnprintf(buf, PAGE_SIZE, "%lld\n", (long long)atomic64_read(&sp->write_cnt)); +} +static DEVICE_ATTR_RO(write_cnt); + +static ssize_t write_byte_cnt_show(struct device *dev, struct device_attribute *attr, char *buf) +{ + struct sg_device *sdp = dev_get_drvdata(dev); + struct sg_dev_stats *sp = sdp->statsp; + + if (!sdp || !sp) + return -EINVAL; + return scnprintf(buf, PAGE_SIZE, "%lld\n", (long long)atomic64_read(&sp->write_byte_cnt)); +} +static DEVICE_ATTR_RO(write_byte_cnt); + +static ssize_t write_ns_show(struct device *dev, struct device_attribute *attr, char *buf) +{ + struct sg_device *sdp = dev_get_drvdata(dev); + struct sg_dev_stats *sp = sdp->statsp; + + if (!sdp || !sp) + return -EINVAL; + return scnprintf(buf, PAGE_SIZE, "%lld\n", (long long)atomic64_read(&sp->tot_write_time)); +} +static DEVICE_ATTR_RO(write_ns); + +static ssize_t in_flight_show(struct device *dev, struct device_attribute *attr, char *buf) +{ + struct sg_device *sdp = dev_get_drvdata(dev); + struct sg_dev_stats *sp = sdp->statsp; + + if (!sdp || !sp) + return -EINVAL; + return scnprintf(buf, PAGE_SIZE, "%lld\n", (long long)atomic64_read(&sp->in_flight)); +} +static DEVICE_ATTR_RO(in_flight); + +static ssize_t io_ns_show(struct device *dev, struct device_attribute *attr, char *buf) +{ + struct sg_device *sdp = dev_get_drvdata(dev); + struct sg_dev_stats *sp = sdp->statsp; + + if (!sdp || !sp) + return -EINVAL; + return scnprintf(buf, PAGE_SIZE, "%lld\n", (long long)atomic64_read(&sp->tot_io_time)); +} +static DEVICE_ATTR_RO(io_ns); + +static ssize_t other_cnt_show(struct device *dev, struct device_attribute *attr, char *buf) +{ + struct sg_device *sdp = dev_get_drvdata(dev); + struct sg_dev_stats *sp = sdp->statsp; + + if (!sdp || !sp) + return -EINVAL; + return scnprintf(buf, PAGE_SIZE, "%lld\n", (long long)atomic64_read(&sp->other_cnt)); +} +static DEVICE_ATTR_RO(other_cnt); + +static ssize_t resid_cnt_show(struct device *dev, struct device_attribute *attr, char *buf) +{ + struct sg_device *sdp = dev_get_drvdata(dev); + struct sg_dev_stats *sp = sdp->statsp; + + if (!sdp || !sp) + return -EINVAL; + return scnprintf(buf, PAGE_SIZE, "%lld\n", (long long)atomic64_read(&sp->resid_cnt)); +} +static DEVICE_ATTR_RO(resid_cnt); + +static struct attribute *sg_stats_attrs[] = { + &dev_attr_read_cnt.attr, + &dev_attr_read_byte_cnt.attr, + &dev_attr_read_ns.attr, + &dev_attr_write_cnt.attr, + &dev_attr_write_byte_cnt.attr, + &dev_attr_write_ns.attr, + &dev_attr_in_flight.attr, + &dev_attr_io_ns.attr, + &dev_attr_other_cnt.attr, + &dev_attr_resid_cnt.attr, + NULL, +}; + +static struct attribute_group sg_stats_group = { + .name = "stats", + .attrs = sg_stats_attrs, +}; + +static const struct attribute_group *sg_dev_groups[] = { + &sg_stats_group, + NULL, +}; + #if IS_ENABLED(SG_PROC_OR_DEBUG_FS) #define SG_SNAPSHOT_DEV_MAX 4 @@ -4623,6 +4816,7 @@ static void sg_dfs_exit(void) {} module_param_named(scatter_elem_sz, scatter_elem_sz, int, 0644); module_param_named(def_reserved_size, def_reserved_size, int, 0644); module_param_named(allow_dio, sg_allow_dio, int, 0644); +module_param_named(no_stats, sg_no_stats, bool, 0644); MODULE_AUTHOR("Douglas Gilbert"); MODULE_DESCRIPTION("SCSI generic (sg) driver"); @@ -4633,5 +4827,6 @@ MODULE_ALIAS_CHARDEV_MAJOR(SCSI_GENERIC_MAJOR); MODULE_PARM_DESC(scatter_elem_sz, "scatter gather element size (default: max(SG_SCATTER_SZ, PAGE_SIZE))"); MODULE_PARM_DESC(def_reserved_size, "size of buffer reserved for each fd"); MODULE_PARM_DESC(allow_dio, "allow direct I/O (default: 0 (disallow)); now ignored"); +MODULE_PARM_DESC(no_stats, "don't collect per device statistics (default: 0)"); module_init(init_sg); module_exit(exit_sg);