On Sun, Sep 23, 2012 at 08:56:31PM +0800, zwu.ker...@gmail.com wrote: > From: Zhi Yong Wu <wu...@linux.vnet.ibm.com> > > Miscellaneous features that implement hot data tracking > and generally make the hot data functions a bit more friendly. > > Signed-off-by: Zhi Yong Wu <wu...@linux.vnet.ibm.com> > --- > fs/direct-io.c | 10 ++++++++++ > include/linux/hot_tracking.h | 11 +++++++++++ > mm/filemap.c | 8 ++++++++ > mm/page-writeback.c | 21 +++++++++++++++++++++ > mm/readahead.c | 9 +++++++++ > 5 files changed, 59 insertions(+), 0 deletions(-) > > diff --git a/fs/direct-io.c b/fs/direct-io.c > index f86c720..3773f44 100644 > --- a/fs/direct-io.c > +++ b/fs/direct-io.c > @@ -37,6 +37,7 @@ > #include <linux/uio.h> > #include <linux/atomic.h> > #include <linux/prefetch.h> > +#include "hot_tracking.h" > > /* > * How many user pages to map in one call to get_user_pages(). This > determines > @@ -1297,6 +1298,15 @@ __blockdev_direct_IO(int rw, struct kiocb *iocb, > struct inode *inode, > prefetch(bdev->bd_queue); > prefetch((char *)bdev->bd_queue + SMP_CACHE_BYTES); > > + /* Hot data tracking */ > + if (TRACK_THIS_INODE(iocb->ki_filp->f_mapping->host) > + && iov_length(iov, nr_segs) > 0) { > + hot_rb_update_freqs(iocb->ki_filp->f_mapping->host, > + (u64)offset, > + (u64)iov_length(iov, nr_segs), > + rw & WRITE); > + }
That's a bit messy. I'd prefer a static inline function that hides all this. e.g. track_hot_inode_ranges(inode, offset, length, rw) { if (inode->i_sb->s_flags & MS_HOT_TRACKING) hot_inode_freq_update(inode, offset, length, rw); } > diff --git a/mm/page-writeback.c b/mm/page-writeback.c > index 5ad5ce2..552c861 100644 > --- a/mm/page-writeback.c > +++ b/mm/page-writeback.c > @@ -35,6 +35,7 @@ > #include <linux/buffer_head.h> /* __set_page_dirty_buffers */ > #include <linux/pagevec.h> > #include <linux/timer.h> > +#include <linux/hot_tracking.h> > #include <trace/events/writeback.h> > > /* > @@ -1895,13 +1896,33 @@ EXPORT_SYMBOL(generic_writepages); > int do_writepages(struct address_space *mapping, struct writeback_control > *wbc) > { > int ret; > + pgoff_t start = 0; > + u64 prev_count = 0, count = 0; > > if (wbc->nr_to_write <= 0) > return 0; > + > + /* Hot data tracking */ > + if (TRACK_THIS_INODE(mapping->host) > + && wbc->range_cyclic) { > + start = mapping->writeback_index << PAGE_CACHE_SHIFT; > + prev_count = (u64)wbc->nr_to_write; > + } Why only wbc->range_cyclic? This won't record things like synchronous writes or fsync-triggered writes, are are far more likely to be to hot ranges in a file... Cheers, Dave. -- Dave Chinner da...@fromorbit.com -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html