From rientjes@google.com Mon May 11 15:59:43 2009 From: Arve Hjønnevåg Date: Mon, 11 May 2009 15:45:09 -0700 (PDT) Subject: Staging: android: lowmemorykiller: Only iterate over process list when needed. To: Greg Kroah-Hartman Cc: Arve Hjønnevåg , San Mehat Message-ID: From: Arve Hjønnevåg Use NR_ACTIVE plus NR_INACTIVE as a size estimate for our fake cache instead the sum of rss. Neither method is accurate. Also skip the process scan, if the amount of memory available is above the largest threshold set. Signed-off-by: Arve Hjønnevåg Cc: David Rientjes Cc: San Mehat Signed-off-by: Greg Kroah-Hartman --- drivers/staging/android/lowmemorykiller.c | 35 ++++++++++++++++++------------ 1 file changed, 21 insertions(+), 14 deletions(-) --- a/drivers/staging/android/lowmemorykiller.c +++ b/drivers/staging/android/lowmemorykiller.c @@ -71,23 +71,30 @@ static int lowmem_shrink(int nr_to_scan, } if(nr_to_scan > 0) lowmem_print(3, "lowmem_shrink %d, %x, ofree %d, ma %d\n", nr_to_scan, gfp_mask, other_free, min_adj); + rem = global_page_state(NR_ACTIVE) + global_page_state(NR_INACTIVE); + if (nr_to_scan <= 0 || min_adj == OOM_ADJUST_MAX + 1) { + lowmem_print(5, "lowmem_shrink %d, %x, return %d\n", nr_to_scan, gfp_mask, rem); + return rem; + } + read_lock(&tasklist_lock); for_each_process(p) { - if(p->oomkilladj >= 0 && p->mm) { - tasksize = get_mm_rss(p->mm); - if(nr_to_scan > 0 && tasksize > 0 && p->oomkilladj >= min_adj) { - if(selected == NULL || - p->oomkilladj > selected->oomkilladj || - (p->oomkilladj == selected->oomkilladj && - tasksize > selected_tasksize)) { - selected = p; - selected_tasksize = tasksize; - lowmem_print(2, "select %d (%s), adj %d, size %d, to kill\n", - p->pid, p->comm, p->oomkilladj, tasksize); - } - } - rem += tasksize; + if (p->oomkilladj < min_adj || !p->mm) + continue; + tasksize = get_mm_rss(p->mm); + if (tasksize <= 0) + continue; + if (selected) { + if (p->oomkilladj < selected->oomkilladj) + continue; + if (p->oomkilladj == selected->oomkilladj && + tasksize <= selected_tasksize) + continue; } + selected = p; + selected_tasksize = tasksize; + lowmem_print(2, "select %d (%s), adj %d, size %d, to kill\n", + p->pid, p->comm, p->oomkilladj, tasksize); } if(selected != NULL) { lowmem_print(1, "send sigkill to %d (%s), adj %d, size %d\n",