refresh patches

debian/patches/patchset-zen/sauce/0015-ZEN-INTERACTIVE-Enable-background-reclaim-of-hugepag.patch

@@ -0,0 +1,59 @@
+From d0ce01e1def080e52770f9a899476bb840807b37 Mon Sep 17 00:00:00 2001
+From: "Jan Alexander Steffens (heftig)" <jan.steffens@gmail.com>
+Date: Mon, 27 Jan 2020 18:21:09 +0100
+Subject: ZEN: INTERACTIVE: Enable background reclaim of hugepages
+
+Use [defer+madvise] as default khugepaged defrag strategy:
+
+For some reason, the default strategy to respond to THP fault fallbacks
+is still just madvise, meaning stall if the program wants transparent
+hugepages, but don't trigger a background reclaim / compaction if THP
+begins to fail allocations.  This creates a snowball affect where we
+still use the THP code paths, but we almost always fail once a system
+has been active and busy for a while.
+
+The option "defer" was created for interactive systems where THP can
+still improve performance.  If we have to fallback to a regular page due
+to an allocation failure or anything else, we will trigger a background
+reclaim and compaction so future THP attempts succeed and previous
+attempts eventually have their smaller pages combined without stalling
+running applications.
+
+We still want madvise to stall applications that explicitely want THP,
+so defer+madvise _does_ make a ton of sense.  Make it the default for
+interactive systems, especially if the kernel maintainer left
+transparent hugepages on "always".
+
+Reasoning and details in the original patch: https://lwn.net/Articles/711248/
+---
+ init/Kconfig     | 4 ++++
+ mm/huge_memory.c | 4 ++++
+ 2 files changed, 8 insertions(+)
+
+--- a/init/Kconfig
++++ b/init/Kconfig
+@@ -168,6 +168,10 @@ config ZEN_INTERACTIVE
+ 	    Default scheduler for SQ..: mq-deadline ->   bfq
+ 	    Default scheduler for MQ..:        none ->   kyber
+ 
++	  --- Virtual Memory Subsystem ---------------------------
++
++	    Background-reclaim hugepages...:   no   ->   yes
++
+ config BROKEN
+ 	bool
+ 
+--- a/mm/huge_memory.c
++++ b/mm/huge_memory.c
+@@ -64,7 +64,11 @@ unsigned long transparent_hugepage_flags
+ #ifdef CONFIG_TRANSPARENT_HUGEPAGE_MADVISE
+ 	(1<<TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG)|
+ #endif
++#ifdef CONFIG_ZEN_INTERACTIVE
++	(1<<TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG)|
++#else
+ 	(1<<TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG)|
++#endif
+ 	(1<<TRANSPARENT_HUGEPAGE_DEFRAG_KHUGEPAGED_FLAG)|
+ 	(1<<TRANSPARENT_HUGEPAGE_USE_ZERO_PAGE_FLAG);
+