Re: [patch 09/10] mm: thrash detection-based file cache sizing

From: Roman Gushchin
Date: Fri Jun 07 2013 - 10:16:20 EST


On 30.05.2013 22:04, Johannes Weiner wrote:
+/*
+ * Monotonic workingset clock for non-resident pages.
+ *
+ * The refault distance of a page is the number of ticks that occurred
+ * between that page's eviction and subsequent refault.
+ *
+ * Every page slot that is taken away from the inactive list is one
+ * more slot the inactive list would have to grow again in order to
+ * hold the current non-resident pages in memory as well.
+ *
+ * As the refault distance needs to reflect the space missing on the
+ * inactive list, the workingset time is advanced every time the
+ * inactive list is shrunk. This means eviction, but also activation.
+ */
+static atomic_long_t workingset_time;

It seems strange to me, that workingset_time is global.
Don't you want to make it per-cgroup?

Two more questions:
1) do you plan to take fadvise's into account somehow?
2) do you plan to use workingset information to enhance
the readahead mechanism?

Thanks!

Regards,
Roman
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/