On Wed, Sep 26, 2012 at 06:59:00AM +0530, Raghavendra D Prabhu wrote:

Hi,


* On Sat, Sep 22, 2012 at 08:49:20PM +0800, Fengguang Wu [off-list ref] wrote:

quoted

On Sat, Sep 22, 2012 at 04:03:11PM +0530, raghu.prabhu13@gmail.com wrote:

quoted

From: Raghavendra D Prabhu <redacted>

If page lookup from radix_tree_lookup is successful and its index page_idx ==
nr_to_read - lookahead_size, then SetPageReadahead never gets called, so this
fixes that.

NAK. Sorry. It's actually an intentional behavior, so that for the
common cases of many cached files that are accessed frequently, no
PG_readahead will be set at all to pointlessly trap into the readahead
routines once and again.

ACK, thanks for explaining that. However, regarding this, I would
like to know if the implications of the patch
51daa88ebd8e0d437289f589af29d4b39379ea76 will still apply if
PG_readahead is not set.

Would you elaborate the implication and the possible problematic case?

Thanks,
Fengguang

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>