diff options
Diffstat (limited to 'mm/thrash.c')
-rw-r--r-- | mm/thrash.c | 120 |
1 files changed, 99 insertions, 21 deletions
diff --git a/mm/thrash.c b/mm/thrash.c index 2372d4ed5dd8..e53f7d02c17c 100644 --- a/mm/thrash.c +++ b/mm/thrash.c @@ -6,7 +6,7 @@ * Released under the GPL, see the file COPYING for details. * * Simple token based thrashing protection, using the algorithm - * described in: http://www.cs.wm.edu/~sjiang/token.pdf + * described in: http://www.cse.ohio-state.edu/hpcs/WWW/HTML/publications/abs05-1.html * * Sep 2006, Ashwin Chaugule <ashwin.chaugule@celunite.com> * Improved algorithm to pass token: @@ -21,14 +21,40 @@ #include <linux/mm.h> #include <linux/sched.h> #include <linux/swap.h> +#include <linux/memcontrol.h> + +#include <trace/events/vmscan.h> + +#define TOKEN_AGING_INTERVAL (0xFF) static DEFINE_SPINLOCK(swap_token_lock); struct mm_struct *swap_token_mm; -static unsigned int global_faults; +struct mem_cgroup *swap_token_memcg; + +#ifdef CONFIG_CGROUP_MEM_RES_CTLR +static struct mem_cgroup *swap_token_memcg_from_mm(struct mm_struct *mm) +{ + struct mem_cgroup *memcg; + + memcg = try_get_mem_cgroup_from_mm(mm); + if (memcg) + css_put(mem_cgroup_css(memcg)); + + return memcg; +} +#else +static struct mem_cgroup *swap_token_memcg_from_mm(struct mm_struct *mm) +{ + return NULL; +} +#endif void grab_swap_token(struct mm_struct *mm) { int current_interval; + unsigned int old_prio = mm->token_priority; + static unsigned int global_faults; + static unsigned int last_aging; global_faults++; @@ -38,40 +64,92 @@ void grab_swap_token(struct mm_struct *mm) return; /* First come first served */ - if (swap_token_mm == NULL) { - mm->token_priority = mm->token_priority + 2; - swap_token_mm = mm; - goto out; + if (!swap_token_mm) + goto replace_token; + + /* + * Usually, we don't need priority aging because long interval faults + * makes priority decrease quickly. But there is one exception. If the + * token owner task is sleeping, it never make long interval faults. + * Thus, we need a priority aging mechanism instead. The requirements + * of priority aging are + * 1) An aging interval is reasonable enough long. Too short aging + * interval makes quick swap token lost and decrease performance. + * 2) The swap token owner task have to get priority aging even if + * it's under sleep. + */ + if ((global_faults - last_aging) > TOKEN_AGING_INTERVAL) { + swap_token_mm->token_priority /= 2; + last_aging = global_faults; } - if (mm != swap_token_mm) { - if (current_interval < mm->last_interval) - mm->token_priority++; - else { - if (likely(mm->token_priority > 0)) - mm->token_priority--; - } - /* Check if we deserve the token */ - if (mm->token_priority > swap_token_mm->token_priority) { - mm->token_priority += 2; - swap_token_mm = mm; - } - } else { - /* Token holder came in again! */ + if (mm == swap_token_mm) { mm->token_priority += 2; + goto update_priority; + } + + if (current_interval < mm->last_interval) + mm->token_priority++; + else { + if (likely(mm->token_priority > 0)) + mm->token_priority--; } + /* Check if we deserve the token */ + if (mm->token_priority > swap_token_mm->token_priority) + goto replace_token; + +update_priority: + trace_update_swap_token_priority(mm, old_prio, swap_token_mm); + out: mm->faultstamp = global_faults; mm->last_interval = current_interval; spin_unlock(&swap_token_lock); + return; + +replace_token: + mm->token_priority += 2; + trace_replace_swap_token(swap_token_mm, mm); + swap_token_mm = mm; + swap_token_memcg = swap_token_memcg_from_mm(mm); + last_aging = global_faults; + goto out; } /* Called on process exit. */ void __put_swap_token(struct mm_struct *mm) { spin_lock(&swap_token_lock); - if (likely(mm == swap_token_mm)) + if (likely(mm == swap_token_mm)) { + trace_put_swap_token(swap_token_mm); swap_token_mm = NULL; + swap_token_memcg = NULL; + } spin_unlock(&swap_token_lock); } + +static bool match_memcg(struct mem_cgroup *a, struct mem_cgroup *b) +{ + if (!a) + return true; + if (!b) + return true; + if (a == b) + return true; + return false; +} + +void disable_swap_token(struct mem_cgroup *memcg) +{ + /* memcg reclaim don't disable unrelated mm token. */ + if (match_memcg(memcg, swap_token_memcg)) { + spin_lock(&swap_token_lock); + if (match_memcg(memcg, swap_token_memcg)) { + trace_disable_swap_token(swap_token_mm); + swap_token_mm = NULL; + swap_token_memcg = NULL; + } + spin_unlock(&swap_token_lock); + } +} |