diff options
Diffstat (limited to 'module/spl/spl-kmem.c')
| -rw-r--r-- | module/spl/spl-kmem.c | 29 |
1 files changed, 20 insertions, 9 deletions
diff --git a/module/spl/spl-kmem.c b/module/spl/spl-kmem.c index fc04604d5..e458c2020 100644 --- a/module/spl/spl-kmem.c +++ b/module/spl/spl-kmem.c @@ -57,6 +57,16 @@ EXPORT_SYMBOL(spl_kmem_cache_expire); module_param(spl_kmem_cache_expire, uint, 0644); MODULE_PARM_DESC(spl_kmem_cache_expire, "By age (0x1) or low memory (0x2)"); +/* + * KMC_RECLAIM_ONCE is set as the default until zfsonlinux/spl#268 is + * definitively resolved. Depending on the system configuration and + * workload this may increase the likelihood of out of memory events. + * For those cases it is advised that this option be set to zero. + */ +unsigned int spl_kmem_cache_reclaim = KMC_RECLAIM_ONCE; +module_param(spl_kmem_cache_reclaim, uint, 0644); +MODULE_PARM_DESC(spl_kmem_cache_reclaim, "Single reclaim pass (0x1)"); + unsigned int spl_kmem_cache_obj_per_slab = SPL_KMEM_CACHE_OBJ_PER_SLAB; module_param(spl_kmem_cache_obj_per_slab, uint, 0644); MODULE_PARM_DESC(spl_kmem_cache_obj_per_slab, "Number of objects per slab"); @@ -2235,7 +2245,7 @@ __spl_kmem_cache_generic_shrinker(struct shrinker *shrink, struct shrink_control *sc) { spl_kmem_cache_t *skc; - int unused = 0; + int alloc = 0; down_read(&spl_kmem_cache_sem); list_for_each_entry(skc, &spl_kmem_cache_list, skc_list) { @@ -2244,24 +2254,25 @@ __spl_kmem_cache_generic_shrinker(struct shrinker *shrink, MAX(sc->nr_to_scan >> fls64(skc->skc_slab_objs), 1)); /* - * Presume everything alloc'ed in reclaimable, this ensures + * Presume everything alloc'ed is reclaimable, this ensures * we are called again with nr_to_scan > 0 so can try and * reclaim. The exact number is not important either so * we forgo taking this already highly contented lock. */ - unused += skc->skc_obj_alloc; + alloc += skc->skc_obj_alloc; } up_read(&spl_kmem_cache_sem); /* - * After performing reclaim always return -1 to indicate we cannot - * perform additional reclaim. This prevents shrink_slabs() from - * repeatedly invoking this generic shrinker and potentially spinning. + * When KMC_RECLAIM_ONCE is set allow only a single reclaim pass. + * This functionality only exists to work around a rare issue where + * shrink_slabs() is repeatedly invoked by many cores causing the + * system to thrash. */ - if (sc->nr_to_scan) - return -1; + if ((spl_kmem_cache_reclaim & KMC_RECLAIM_ONCE) && sc->nr_to_scan) + return (-1); - return unused; + return MAX((alloc * sysctl_vfs_cache_pressure) / 100, 0); } SPL_SHRINKER_CALLBACK_WRAPPER(spl_kmem_cache_generic_shrinker); |