From mboxrd@z Thu Jan 1 00:00:00 1970 From: jay.aurabind@gmail.com (Jay Aurabind) Date: Fri, 25 Apr 2014 19:41:04 +0530 Subject: Kworker and jbd2 constantly writing to hdd In-Reply-To: References: <535A0647.1090601@gmail.com> Message-ID: <535A6CF8.6030901@gmail.com> To: kernelnewbies@lists.kernelnewbies.org List-Id: kernelnewbies.lists.kernelnewbies.org On Friday 25 April 2014 05:48 PM, Mulyadi Santosa wrote: > > > Could it be a power management system trying to spin down your disk to > save power? > > Try to alter the power management variable from your desktop > environment settings. Try to make it less aggresive. Tried setting APM to 254, so as not to attempt a spin down, but no change in the situation. But even if its the system trying to spin down, would it get listed as a write operation? Isnt it supposed to be an ioctl ? Does iotop consider ioctls as a write ? Its man page doesnt mention anything about ioctls. > > > ALso, it could be the I/O scheduler too. Try to switch to noop and see > if it change the situation > Under noop, deadline and cfq, the situation remains the same. Dont have any other schedulers. The kworker I mentioned was spotted from the output of iotop -o. I kept "watching" /proc/meminfo while kworker was popping up. I found that even though the same kworker showed up periodically at 1 second, meminfo's "dirty" entry was getting modified only at about 45 seconds, with 8KB, and subsequently after 1 minute, dirty would roll back to zero, (probably indicating a real disk write?). Iotop says it reports acutal I/O happening, and this seems consistent with the above observation. But in reality, my HDD indicator is blinking at 1 second, synchronous to kworker. Does the hdd indicator blink under any circumstances other than a read or write? BTW its a light blink, not a strong one like when we do some serious I/O. Can you please do an "iotop -o" and see if you also have the same kworker popping up? Thanks and Regards, Jay -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 278 bytes Desc: OpenPGP digital signature Url : http://lists.kernelnewbies.org/pipermail/kernelnewbies/attachments/20140425/48565801/attachment.bin