I am experimenting with the kernel (as some of you may know), and I have added a whole slew of traces in some relatively sensitive code in the lower levels of the page cache and i/o functions. Most of this tracing not only works but is highly revealing as to what the kernel is doing and why.

However, I am now getting this odd content in the trace log (dmesg), and I cannot figure out what it is or why it is there. If anyone recognizes this situation, I invite comment and suggestions on how to eliminate or decipher it:

4296757675 pdflush(80): do_writepages: map>ops>wrtpgs ffffffffa0195ff5 4296757675 pdflush(80): mpage_writepages w/b index 49728 pages 256000 <7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7> <7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7> <7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7> <7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7> <7><7><7><7><7>__bio_add_page: 2x ph 88>128 || hw 88>88 || 360448>max ffffffff802525d8 generic_make_request(bio 000001017c745300) 50729472, 704 __make_request(q 00000101b9293870, bio 000001017c745300: sdc; 50729600, 704) ll_new_hw_segment: 70 + 29 > 88 <7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7> <7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7> <7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7> <7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7><7> <7><7><7><7>__bio_add_page: 2x ph 88>128 || hw 88>88 || 360448>max ffffffff802525d8 generic_make_request(bio 000001017c745a80) 50730176, 704 __make_request(q 00000101b9293870, bio 000001017c745a80: sdc; 50730304, 704) 4296757684 swapper(0): dl_mv2dsp: sdc start 50710368 secs 1408

(The lines with the <7>s in them are long - I wrapped them for ease of reading and to keep the width down somewhat.)

Or should I post this in the lkml?

Thanks.