Hi, I've spotted that the periodic write-back threads wakes up every 5 seconds, even though there are no dirty data. And it still wakes up and wake up and disturbs the CPU which is resting in a low power consumption state. I've tried to optimize this a bit and make the periodic write-back stop when there are no dirty data. Here are 2 patches which kind of help. They are just quick hacks. I did not want to spend much time on this and I'd like to get some comments/directions first: * I'm not sure I went the right path; * there are new per-BDI patches from Jens, and I probably should work on top of them. AFAIU, the periodic write-back may be stopped if there are no dirty inodes and no dirty super-blocks. And it should start an inode or superblock is marked as dirty. For inodes, I've hooked to '__mark_inode_dirty()'. For superblocks. Well, probably a new VFS helper like 'mark_sb_dirty()' should be introduced. Also, FSes currently may mark SB as clean directly, but probably they should use a 'mark_sb_clean()' helper. FSes should not touch sb->s_dirt directly. Anyway, I have not implemented this part. -- Best Regards, Artem Bityutskiy (Ð?Ñ?Ñ?Ñ?м Ð?иÑ?Ñ?Ñ?кий) -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
