Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756514Ab0FGH7D (ORCPT ); Mon, 7 Jun 2010 03:59:03 -0400 Received: from fgwmail7.fujitsu.co.jp ([192.51.44.37]:54277 "EHLO fgwmail7.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752724Ab0FGH7A (ORCPT ); Mon, 7 Jun 2010 03:59:00 -0400 X-SecurityPolicyCheck-FJ: OK by FujitsuOutboundMailChecker v1.4.0 Message-ID: <4C0CA681.5000100@jp.fujitsu.com> Date: Mon, 07 Jun 2010 16:57:53 +0900 From: Kei Tokunaga User-Agent: Thunderbird 2.0.0.23 (Windows/20090812) MIME-Version: 1.0 To: rostedt@goodmis.org CC: LKML , Ingo Molnar , Frederic Weisbecker , "Martin K. Petersen" , James Bottomley , Tomohiro Kusumi , Xiao Guangrong , Li Zefan , Kei Tokunaga Subject: Re: [PATCH v2][GIT PULL][v2.6.35] tracing/events: Convert format output to seq_file References: <1275594103.15884.35.camel@gandalf.stny.rr.com> <1275622026.15884.72.camel@gandalf.stny.rr.com> In-Reply-To: <1275622026.15884.72.camel@gandalf.stny.rr.com> Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 8906 Lines: 314 Steven Rostedt wrote: > Ingo, > > Please pull the latest tip/perf/urgent-2 tree, which can be found at: > > git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace.git > tip/perf/urgent-2 > > > Steven Rostedt (1): > tracing/events: Convert format output to seq_file > > ---- > kernel/trace/trace_events.c | 208 +++++++++++++++++++++++++++++-------------- > 1 files changed, 141 insertions(+), 67 deletions(-) > --------------------------- > commit bcaa10360f3b2a623453a9fb10ef77aafeef8bb6 > Author: Steven Rostedt > Date: Thu Jun 3 15:21:34 2010 -0400 > > tracing/events: Convert format output to seq_file > > Two new events were added that broke the current format output. > > Both from the SCSI system: scsi_dispatch_cmd_done and scsi_dispatch_cmd_timeout > > The reason is that their print_fmt exceeded a page size. Since the output > of the format used simple_read_from_buffer and trace_seq, it was limited > to a page size in output. > > This patch converts the printing of the format of an event into seq_file, > which allows greater than a page size to be shown. > > I diffed all event formats comparing the output with and without this > patch. All matched except for the above two, which showed just: > > FORMAT TOO BIG > > without this patch, but now properly displays the output with this patch. > > v2: Remove updating *pos in seq start function. > [ Thanks to Li Zefan for pointing that out ] There's been an oversight... Thanks a lot for finding and fixing this! I built a kernel with the patch applied and confirmed the issue is fixed on my box. Tested-by: Kei Tokunaga > Reviewed-by: Li Zefan > Cc: Martin K. Petersen > Cc: Kei Tokunaga > Cc: James Bottomley > Cc: Tomohiro Kusumi > Cc: Xiao Guangrong > Signed-off-by: Steven Rostedt > > diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c > index 53cffc0..45a8968 100644 > --- a/kernel/trace/trace_events.c > +++ b/kernel/trace/trace_events.c > @@ -29,6 +29,8 @@ DEFINE_MUTEX(event_mutex); > > LIST_HEAD(ftrace_events); > > +#define COMMON_FIELD_COUNT 5 > + > struct list_head * > trace_get_fields(struct ftrace_event_call *event_call) > { > @@ -544,85 +546,155 @@ out: > return ret; > } > > -static ssize_t > -event_format_read(struct file *filp, char __user *ubuf, size_t cnt, > - loff_t *ppos) > +enum { > + FORMAT_HEADER = 1, > + FORMAT_PRINTFMT = 2, > +}; > + > +static void *f_next(struct seq_file *m, void *v, loff_t *pos) > { > - struct ftrace_event_call *call = filp->private_data; > + struct ftrace_event_call *call = m->private; > struct ftrace_event_field *field; > struct list_head *head; > - struct trace_seq *s; > - int common_field_count = 5; > - char *buf; > - int r = 0; > - > - if (*ppos) > - return 0; > + loff_t index = *pos; > > - s = kmalloc(sizeof(*s), GFP_KERNEL); > - if (!s) > - return -ENOMEM; > + (*pos)++; > > - trace_seq_init(s); > + head = trace_get_fields(call); > > - trace_seq_printf(s, "name: %s\n", call->name); > - trace_seq_printf(s, "ID: %d\n", call->event.type); > - trace_seq_printf(s, "format:\n"); > + switch ((unsigned long)v) { > + case FORMAT_HEADER: > > - head = trace_get_fields(call); > - list_for_each_entry_reverse(field, head, link) { > - /* > - * Smartly shows the array type(except dynamic array). > - * Normal: > - * field:TYPE VAR > - * If TYPE := TYPE[LEN], it is shown: > - * field:TYPE VAR[LEN] > - */ > - const char *array_descriptor = strchr(field->type, '['); > - > - if (!strncmp(field->type, "__data_loc", 10)) > - array_descriptor = NULL; > - > - if (!array_descriptor) { > - r = trace_seq_printf(s, "\tfield:%s %s;\toffset:%u;" > - "\tsize:%u;\tsigned:%d;\n", > - field->type, field->name, field->offset, > - field->size, !!field->is_signed); > - } else { > - r = trace_seq_printf(s, "\tfield:%.*s %s%s;\toffset:%u;" > - "\tsize:%u;\tsigned:%d;\n", > - (int)(array_descriptor - field->type), > - field->type, field->name, > - array_descriptor, field->offset, > - field->size, !!field->is_signed); > - } > + if (unlikely(list_empty(head))) > + return NULL; > > - if (--common_field_count == 0) > - r = trace_seq_printf(s, "\n"); > + field = list_entry(head->prev, struct ftrace_event_field, link); > + return field; > > - if (!r) > - break; > + case FORMAT_PRINTFMT: > + /* all done */ > + return NULL; > } > > - if (r) > - r = trace_seq_printf(s, "\nprint fmt: %s\n", > - call->print_fmt); > + /* > + * To separate common fields from event fields, the > + * LSB is set on the first event field. Clear it in case. > + */ > + v = (void *)((unsigned long)v & ~1L); > > - if (!r) { > - /* > - * ug! The format output is bigger than a PAGE!! > - */ > - buf = "FORMAT TOO BIG\n"; > - r = simple_read_from_buffer(ubuf, cnt, ppos, > - buf, strlen(buf)); > - goto out; > + field = v; > + if (field->link.prev == head) > + return (void *)FORMAT_PRINTFMT; > + > + field = list_entry(field->link.prev, struct ftrace_event_field, link); > + > + /* Set the LSB to notify f_show to print an extra newline */ > + if (index == COMMON_FIELD_COUNT) > + field = (struct ftrace_event_field *) > + ((unsigned long)field | 1); > + > + return field; > +} > + > +static void *f_start(struct seq_file *m, loff_t *pos) > +{ > + loff_t l = 0; > + void *p; > + > + /* Start by showing the header */ > + if (!*pos) > + return (void *)FORMAT_HEADER; > + > + p = (void *)FORMAT_HEADER; > + do { > + p = f_next(m, p, &l); > + } while (p && l < *pos); > + > + return p; > +} > + > +static int f_show(struct seq_file *m, void *v) > +{ > + struct ftrace_event_call *call = m->private; > + struct ftrace_event_field *field; > + const char *array_descriptor; > + > + switch ((unsigned long)v) { > + case FORMAT_HEADER: > + seq_printf(m, "name: %s\n", call->name); > + seq_printf(m, "ID: %d\n", call->event.type); > + seq_printf(m, "format:\n"); > + return 0; > + > + case FORMAT_PRINTFMT: > + seq_printf(m, "\nprint fmt: %s\n", > + call->print_fmt); > + return 0; > } > > - r = simple_read_from_buffer(ubuf, cnt, ppos, > - s->buffer, s->len); > - out: > - kfree(s); > - return r; > + /* > + * To separate common fields from event fields, the > + * LSB is set on the first event field. Clear it and > + * print a newline if it is set. > + */ > + if ((unsigned long)v & 1) { > + seq_putc(m, '\n'); > + v = (void *)((unsigned long)v & ~1L); > + } > + > + field = v; > + > + /* > + * Smartly shows the array type(except dynamic array). > + * Normal: > + * field:TYPE VAR > + * If TYPE := TYPE[LEN], it is shown: > + * field:TYPE VAR[LEN] > + */ > + array_descriptor = strchr(field->type, '['); > + > + if (!strncmp(field->type, "__data_loc", 10)) > + array_descriptor = NULL; > + > + if (!array_descriptor) > + seq_printf(m, "\tfield:%s %s;\toffset:%u;\tsize:%u;\tsigned:%d;\n", > + field->type, field->name, field->offset, > + field->size, !!field->is_signed); > + else > + seq_printf(m, "\tfield:%.*s %s%s;\toffset:%u;\tsize:%u;\tsigned:%d;\n", > + (int)(array_descriptor - field->type), > + field->type, field->name, > + array_descriptor, field->offset, > + field->size, !!field->is_signed); > + > + return 0; > +} > + > +static void f_stop(struct seq_file *m, void *p) > +{ > +} > + > +static const struct seq_operations trace_format_seq_ops = { > + .start = f_start, > + .next = f_next, > + .stop = f_stop, > + .show = f_show, > +}; > + > +static int trace_format_open(struct inode *inode, struct file *file) > +{ > + struct ftrace_event_call *call = inode->i_private; > + struct seq_file *m; > + int ret; > + > + ret = seq_open(file, &trace_format_seq_ops); > + if (ret < 0) > + return ret; > + > + m = file->private_data; > + m->private = call; > + > + return 0; > } > > static ssize_t > @@ -820,8 +892,10 @@ static const struct file_operations ftrace_enable_fops = { > }; > > static const struct file_operations ftrace_event_format_fops = { > - .open = tracing_open_generic, > - .read = event_format_read, > + .open = trace_format_open, > + .read = seq_read, > + .llseek = seq_lseek, > + .release = seq_release, > }; > > static const struct file_operations ftrace_event_id_fops = { > > > > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/