113 lines
3.0 KiB
Diff
113 lines
3.0 KiB
Diff
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From: Jan Blunck <jblunck@suse.de>
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Subject: blkparse: Track smallest sequence read per device
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When running
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blktrace -d /dev/sda -o - | ./blkparse -i -
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only a few traces are actually printed out on stdout. Most of the traces are
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queued up and only after hitting ^C and therefore forcing show_entries_rb()
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they are printed out. I noticed that once pci->smallest_seq_read is zero,
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check_sequence always returns 1:
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static int check_sequence(struct per_dev_info *pdi, struct trace *t, int
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force)
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{
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...
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if (expected_sequence < pci->smallest_seq_read) {
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__t = trace_rb_find_last(pdi, pci, expected_sequence);
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if (!__t)
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goto skip;
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__put_trace_last(pdi, __t);
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return 0;
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} else if (!force) {
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return 1;
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...
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}
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This patch fixes the problem by using a variable per device to keep track of
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the smallest sequence read on each cpu.
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--
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---
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blkparse.c | 19 +++++++++++--------
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1 file changed, 11 insertions(+), 8 deletions(-)
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--- a/blkparse.c
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+++ b/blkparse.c
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@@ -58,6 +58,8 @@ struct per_dev_info {
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unsigned int max_depth[2];
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unsigned int cur_depth[2];
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+ unsigned long smallest_seq_read;
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+
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struct rb_root rb_track;
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int nfiles;
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@@ -401,6 +403,7 @@ static struct per_dev_info *get_dev_info
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pdi->dev = dev;
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pdi->first_reported_time = 0;
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pdi->last_read_time = 0;
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+ pdi->smallest_seq_read = -1UL;
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return pdi;
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}
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@@ -1969,10 +1972,14 @@ static int sort_entries(unsigned long lo
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struct per_dev_info *pdi = NULL;
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struct per_cpu_info *pci = NULL;
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struct trace *t;
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+ int i;
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if (!genesis_time)
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find_genesis();
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+ for (i = 0; i < ndevices; i++)
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+ devices[i].smallest_seq_read = -1UL;
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+
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*youngest = 0;
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while ((t = trace_list) != NULL) {
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struct blk_io_trace *bit = t->bit;
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@@ -1992,8 +1999,8 @@ static int sort_entries(unsigned long lo
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if (!pci || pci->cpu != bit->cpu)
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pci = get_cpu_info(pdi, bit->cpu);
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- if (bit->sequence < pci->smallest_seq_read)
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- pci->smallest_seq_read = bit->sequence;
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+ if (bit->sequence < pdi->smallest_seq_read)
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+ pdi->smallest_seq_read = bit->sequence;
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if (check_stopwatch(bit)) {
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bit_free(bit);
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@@ -2065,7 +2072,7 @@ static int check_sequence(struct per_dev
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*/
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if (bit->sequence == 1)
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return 0;
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- if (bit->sequence == pci->smallest_seq_read)
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+ if (bit->sequence == pdi->smallest_seq_read)
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return 0;
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return check_cpu_map(pdi);
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@@ -2078,7 +2085,7 @@ static int check_sequence(struct per_dev
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* we may not have seen that sequence yet. if we are not doing
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* the final run, break and wait for more entries.
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*/
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- if (expected_sequence < pci->smallest_seq_read) {
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+ if (expected_sequence < pdi->smallest_seq_read) {
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__t = trace_rb_find_last(pdi, pci, expected_sequence);
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if (!__t)
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goto skip;
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@@ -2620,10 +2627,6 @@ static void do_pipe(int fd)
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fdblock = -1;
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while ((events = read_events(fd, 0, &fdblock)) > 0) {
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read_sequence++;
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-
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-#if 0
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- smallest_seq_read = -1U;
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-#endif
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if (sort_entries(&youngest))
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break;
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