On 6/13/2013 8:29 AM, Tomasz Stanislawski wrote: > On ARM, sizeof(struct smack_master_list) == 12. Allocation by kmalloc() uses a > 32-byte-long chunk to allocate 12 bytes. Just ask ksize(). It means that 63% > of memory is simply wasted for padding bytes. > > The problem is fixed in this patch by using kmem_cache. The cache allocates > struct smack_master_list using 16-byte-long chunks according to ksize(). This > reduces amount of used memory by 50%.
As with patch 4, I need to see performance numbers. Saving 50% is good, but if there are 20,000 rules you're only saving 320K of memory. > > Signed-off-by: Tomasz Stanislawski <[email protected]> > --- > security/smack/smack.h | 7 +++++++ > security/smack/smack_lsm.c | 8 ++++++++ > security/smack/smackfs.c | 8 ++------ > 3 files changed, 17 insertions(+), 6 deletions(-) > > diff --git a/security/smack/smack.h b/security/smack/smack.h > index 38ba673..463f818 100644 > --- a/security/smack/smack.h > +++ b/security/smack/smack.h > @@ -194,6 +194,12 @@ struct smk_audit_info { > struct smack_audit_data sad; > #endif > }; > + > +struct smack_master_list { > + struct list_head list; > + struct smack_rule *smk_rule; > +}; > + > /* > * These functions are in smack_lsm.c > */ > @@ -235,6 +241,7 @@ extern struct list_head smk_netlbladdr_list; > > /* Cache for fast and thrifty allocations */ > extern struct kmem_cache *smack_rule_cache; > +extern struct kmem_cache *smack_master_list_cache; > > extern struct security_operations smack_ops; > > diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c > index 7aa696a..1d4a1b0 100644 > --- a/security/smack/smack_lsm.c > +++ b/security/smack/smack_lsm.c > @@ -3566,6 +3566,7 @@ static __init void init_smack_known_list(void) > > /* KMEM caches for fast and thrifty allocations */ > struct kmem_cache *smack_rule_cache; > +struct kmem_cache *smack_master_list_cache; > > /** > * smack_init - initialize the smack system > @@ -3584,9 +3585,16 @@ static __init int smack_init(void) > if (!smack_rule_cache) > return -ENOMEM; > > + smack_master_list_cache = KMEM_CACHE(smack_master_list, 0); > + if (!smack_master_list_cache) { > + kmem_cache_destroy(smack_rule_cache); > + return -ENOMEM; > + } > + > tsp = new_task_smack(smack_known_floor.smk_known, > smack_known_floor.smk_known, GFP_KERNEL); > if (tsp == NULL) { > + kmem_cache_destroy(smack_master_list_cache); > kmem_cache_destroy(smack_rule_cache); > return -ENOMEM; > } > diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c > index c08b1ec..c7a1b0d 100644 > --- a/security/smack/smackfs.c > +++ b/security/smack/smackfs.c > @@ -104,11 +104,6 @@ LIST_HEAD(smk_netlbladdr_list); > * Rule lists are maintained for each label. > * This master list is just for reading /smack/load and /smack/load2. > */ > -struct smack_master_list { > - struct list_head list; > - struct smack_rule *smk_rule; > -}; > - > LIST_HEAD(smack_rule_list); > > struct smack_parsed_rule { > @@ -233,7 +228,8 @@ static int smk_set_access(struct smack_parsed_rule *srp, > * it needs to get added for reporting. > */ > if (global) { > - smlp = kzalloc(sizeof(*smlp), GFP_KERNEL); > + smlp = kmem_cache_zalloc(smack_master_list_cache, > + GFP_KERNEL); > if (smlp != NULL) { > smlp->smk_rule = sp; > list_add_rcu(&smlp->list, &smack_rule_list); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
