| Message ID | 1554343303-11880-1-git-send-email-huangzhaoyang@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | mm:workingset use real time to judge activity of the file page | expand |
On Wed, Apr 3, 2019 at 7:03 PM Zhaoyang Huang <huangzhaoyang@gmail.com> wrote: > > From: Zhaoyang Huang <Zhaoyang Huang@unisoc.com> > > In previous implementation, the number of refault pages is used > for judging the refault period of each page, which is not precised. > We introduce the timestamp into the workingset's entry to measure > the file page's activity. > > The patch is tested on an Android system, which can be described as > comparing the launch time of an application between a huge memory > consumption. The result is launch time decrease 50% and the page fault > during the test decrease 80%. > > Signed-off-by: Zhaoyang Huang <huangzhaoyang@gmail.com> > --- > include/linux/mmzone.h | 2 ++ > mm/workingset.c | 24 +++++++++++++++++------- > 2 files changed, 19 insertions(+), 7 deletions(-) > > diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h > index 32699b2..c38ba0a 100644 > --- a/include/linux/mmzone.h > +++ b/include/linux/mmzone.h > @@ -240,6 +240,8 @@ struct lruvec { > atomic_long_t inactive_age; > /* Refaults at the time of last reclaim cycle */ > unsigned long refaults; > + atomic_long_t refaults_ratio; > + atomic_long_t prev_fault; > #ifdef CONFIG_MEMCG > struct pglist_data *pgdat; > #endif > diff --git a/mm/workingset.c b/mm/workingset.c > index 40ee02c..6361853 100644 > --- a/mm/workingset.c > +++ b/mm/workingset.c > @@ -159,7 +159,7 @@ > NODES_SHIFT + \ > MEM_CGROUP_ID_SHIFT) > #define EVICTION_MASK (~0UL >> EVICTION_SHIFT) > - > +#define EVICTION_JIFFIES (BITS_PER_LONG >> 3) > /* > * Eviction timestamps need to be able to cover the full range of > * actionable refaults. However, bits are tight in the radix tree > @@ -175,18 +175,22 @@ static void *pack_shadow(int memcgid, pg_data_t *pgdat, unsigned long eviction) > eviction >>= bucket_order; > eviction = (eviction << MEM_CGROUP_ID_SHIFT) | memcgid; > eviction = (eviction << NODES_SHIFT) | pgdat->node_id; > + eviction = (eviction << EVICTION_JIFFIES) | (jiffies >> EVICTION_JIFFIES); > eviction = (eviction << RADIX_TREE_EXCEPTIONAL_SHIFT); > > return (void *)(eviction | RADIX_TREE_EXCEPTIONAL_ENTRY); > } > > static void unpack_shadow(void *shadow, int *memcgidp, pg_data_t **pgdat, > - unsigned long *evictionp) > + unsigned long *evictionp, unsigned long *prev_jiffp) > { > unsigned long entry = (unsigned long)shadow; > int memcgid, nid; > + unsigned long prev_jiff; > > entry >>= RADIX_TREE_EXCEPTIONAL_SHIFT; > + entry >>= EVICTION_JIFFIES; > + prev_jiff = (entry & ((1UL << EVICTION_JIFFIES) - 1)) << EVICTION_JIFFIES; > nid = entry & ((1UL << NODES_SHIFT) - 1); > entry >>= NODES_SHIFT; > memcgid = entry & ((1UL << MEM_CGROUP_ID_SHIFT) - 1); > @@ -195,6 +199,7 @@ static void unpack_shadow(void *shadow, int *memcgidp, pg_data_t **pgdat, > *memcgidp = memcgid; > *pgdat = NODE_DATA(nid); > *evictionp = entry << bucket_order; > + *prev_jiffp = prev_jiff; > } > > /** > @@ -242,8 +247,12 @@ bool workingset_refault(void *shadow) > unsigned long refault; > struct pglist_data *pgdat; > int memcgid; > + unsigned long refault_ratio; > + unsigned long prev_jiff; > + unsigned long avg_refault_time; > + unsigned long refault_time; > > - unpack_shadow(shadow, &memcgid, &pgdat, &eviction); > + unpack_shadow(shadow, &memcgid, &pgdat, &eviction, &prev_jiff); > > rcu_read_lock(); > /* > @@ -288,10 +297,11 @@ bool workingset_refault(void *shadow) > * list is not a problem. > */ > refault_distance = (refault - eviction) & EVICTION_MASK; > - > inc_lruvec_state(lruvec, WORKINGSET_REFAULT); > - > - if (refault_distance <= active_file) { > + lruvec->refaults_ratio = atomic_long_read(&lruvec->inactive_age) / jiffies; I also wonder how many times the division above yields a 0... > + refault_time = jiffies - prev_jiff; > + avg_refault_time = refault_distance / lruvec->refaults_ratio; and then used here as a denominator. > + if (refault_time <= avg_refault_time) { > inc_lruvec_state(lruvec, WORKINGSET_ACTIVATE); > rcu_read_unlock(); > return true; > @@ -521,7 +531,7 @@ static int __init workingset_init(void) > * some more pages at runtime, so keep working with up to > * double the initial memory by using totalram_pages as-is. > */ > - timestamp_bits = BITS_PER_LONG - EVICTION_SHIFT; > + timestamp_bits = BITS_PER_LONG - EVICTION_SHIFT - EVICTION_JIFFIES; > max_order = fls_long(totalram_pages - 1); > if (max_order > timestamp_bits) > bucket_order = max_order - timestamp_bits; > -- > 1.9.1 >
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 32699b2..c38ba0a 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -240,6 +240,8 @@ struct lruvec { atomic_long_t inactive_age; /* Refaults at the time of last reclaim cycle */ unsigned long refaults; + atomic_long_t refaults_ratio; + atomic_long_t prev_fault; #ifdef CONFIG_MEMCG struct pglist_data *pgdat; #endif diff --git a/mm/workingset.c b/mm/workingset.c index 40ee02c..6361853 100644 --- a/mm/workingset.c +++ b/mm/workingset.c @@ -159,7 +159,7 @@ NODES_SHIFT + \ MEM_CGROUP_ID_SHIFT) #define EVICTION_MASK (~0UL >> EVICTION_SHIFT) - +#define EVICTION_JIFFIES (BITS_PER_LONG >> 3) /* * Eviction timestamps need to be able to cover the full range of * actionable refaults. However, bits are tight in the radix tree @@ -175,18 +175,22 @@ static void *pack_shadow(int memcgid, pg_data_t *pgdat, unsigned long eviction) eviction >>= bucket_order; eviction = (eviction << MEM_CGROUP_ID_SHIFT) | memcgid; eviction = (eviction << NODES_SHIFT) | pgdat->node_id; + eviction = (eviction << EVICTION_JIFFIES) | (jiffies >> EVICTION_JIFFIES); eviction = (eviction << RADIX_TREE_EXCEPTIONAL_SHIFT); return (void *)(eviction | RADIX_TREE_EXCEPTIONAL_ENTRY); } static void unpack_shadow(void *shadow, int *memcgidp, pg_data_t **pgdat, - unsigned long *evictionp) + unsigned long *evictionp, unsigned long *prev_jiffp) { unsigned long entry = (unsigned long)shadow; int memcgid, nid; + unsigned long prev_jiff; entry >>= RADIX_TREE_EXCEPTIONAL_SHIFT; + entry >>= EVICTION_JIFFIES; + prev_jiff = (entry & ((1UL << EVICTION_JIFFIES) - 1)) << EVICTION_JIFFIES; nid = entry & ((1UL << NODES_SHIFT) - 1); entry >>= NODES_SHIFT; memcgid = entry & ((1UL << MEM_CGROUP_ID_SHIFT) - 1); @@ -195,6 +199,7 @@ static void unpack_shadow(void *shadow, int *memcgidp, pg_data_t **pgdat, *memcgidp = memcgid; *pgdat = NODE_DATA(nid); *evictionp = entry << bucket_order; + *prev_jiffp = prev_jiff; } /** @@ -242,8 +247,12 @@ bool workingset_refault(void *shadow) unsigned long refault; struct pglist_data *pgdat; int memcgid; + unsigned long refault_ratio; + unsigned long prev_jiff; + unsigned long avg_refault_time; + unsigned long refault_time; - unpack_shadow(shadow, &memcgid, &pgdat, &eviction); + unpack_shadow(shadow, &memcgid, &pgdat, &eviction, &prev_jiff); rcu_read_lock(); /* @@ -288,10 +297,11 @@ bool workingset_refault(void *shadow) * list is not a problem. */ refault_distance = (refault - eviction) & EVICTION_MASK; - inc_lruvec_state(lruvec, WORKINGSET_REFAULT); - - if (refault_distance <= active_file) { + lruvec->refaults_ratio = atomic_long_read(&lruvec->inactive_age) / jiffies; + refault_time = jiffies - prev_jiff; + avg_refault_time = refault_distance / lruvec->refaults_ratio; + if (refault_time <= avg_refault_time) { inc_lruvec_state(lruvec, WORKINGSET_ACTIVATE); rcu_read_unlock(); return true; @@ -521,7 +531,7 @@ static int __init workingset_init(void) * some more pages at runtime, so keep working with up to * double the initial memory by using totalram_pages as-is. */ - timestamp_bits = BITS_PER_LONG - EVICTION_SHIFT; + timestamp_bits = BITS_PER_LONG - EVICTION_SHIFT - EVICTION_JIFFIES; max_order = fls_long(totalram_pages - 1); if (max_order > timestamp_bits) bucket_order = max_order - timestamp_bits;