mm: Boost when memory pressure becomes high

When memory pressure starts to balloon, allocation latency takes a hit
as the page allocator continuously tries to find a way to free up some
pages. Boosting when this occurs can significantly help reduce
allocation latency, preventing noticeable lag from being observed.
Signed-off-by: Sultan Alsawaf <sultan@kerneltoast.com>
Signed-off-by: ronaxdevil <pratabidya.007@gmail.com>
Signed-off-by: arnavpuranik <puranikarnav@gmail.com>

mm/page_alloc.c

@@ -62,6 +62,7 @@
 #include <linux/sched/rt.h>
 #include <linux/page_owner.h>
 #include <linux/kthread.h>
+#include <linux/devfreq_boost.h>
 
 #include <asm/sections.h>
 #include <asm/tlbflush.h>
@@ -3291,6 +3292,9 @@ retry:
 	if (gfp_mask & __GFP_NORETRY)
 		goto noretry;
 
+				/* Boost when memory is low so allocation latency doesn't get too bad */
+				devfreq_boost_kick_max(DEVFREQ_MSM_CPUBW, 100);
+
 	/* Keep reclaiming pages as long as there is reasonable progress */
 	pages_reclaimed += did_some_progress;
 	if ((did_some_progress && order <= PAGE_ALLOC_COSTLY_ORDER) ||