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| author | Tejun Heo <tj@kernel.org> | 2015-08-19 00:55:11 +0300 |
|---|---|---|
| committer | Jens Axboe <axboe@fb.com> | 2015-08-19 01:49:16 +0300 |
| commit | 001bea73e70efdf48a9e00188cf302f6b6aed2bf (patch) | |
| tree | 73797e7ac03b5e3e4fd9a3dc90c43f89b1ed57e0 /block/cfq-iosched.c | |
| parent | 3e41871046bfe0ba7d122a1f14f0c1db2dca0256 (diff) | |
| download | linux-001bea73e70efdf48a9e00188cf302f6b6aed2bf.tar.xz | |
blkcg: replace blkcg_policy->pd_size with ->pd_alloc/free_fn() methods
A blkg (blkcg_gq) represents the relationship between a cgroup and
request_queue. Each active policy has a pd (blkg_policy_data) on each
blkg. The pd's were allocated by blkcg core and each policy could
request to allocate extra space at the end by setting
blkcg_policy->pd_size larger than the size of pd.
This is a bit unusual but was done this way mostly to simplify error
handling and all the existing use cases could be handled this way;
however, this is becoming too restrictive now that percpu memory can
be allocated without blocking.
This introduces two new mandatory blkcg_policy methods - pd_alloc_fn()
and pd_free_fn() - which are used to allocate and release pd for a
given policy. As pd allocation is now done from policy side, it can
simply allocate a larger area which embeds pd at the beginning. This
change makes ->pd_size pointless. Removed.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'block/cfq-iosched.c')
| -rw-r--r-- | block/cfq-iosched.c | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index 9c9ec7cc9f99..69ce2883099e 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -1582,6 +1582,11 @@ static void cfq_cpd_init(const struct blkcg *blkcg) } } +static struct blkg_policy_data *cfq_pd_alloc(gfp_t gfp, int node) +{ + return kzalloc_node(sizeof(struct cfq_group), gfp, node); +} + static void cfq_pd_init(struct blkcg_gq *blkg) { struct cfq_group *cfqg = blkg_to_cfqg(blkg); @@ -1618,6 +1623,11 @@ static void cfq_pd_offline(struct blkcg_gq *blkg) cfqg_stats_xfer_dead(cfqg); } +static void cfq_pd_free(struct blkg_policy_data *pd) +{ + return kfree(pd); +} + /* offset delta from cfqg->stats to cfqg->dead_stats */ static const int dead_stats_off_delta = offsetof(struct cfq_group, dead_stats) - offsetof(struct cfq_group, stats); @@ -4633,13 +4643,14 @@ static struct elevator_type iosched_cfq = { #ifdef CONFIG_CFQ_GROUP_IOSCHED static struct blkcg_policy blkcg_policy_cfq = { - .pd_size = sizeof(struct cfq_group), .cpd_size = sizeof(struct cfq_group_data), .cftypes = cfq_blkcg_files, .cpd_init_fn = cfq_cpd_init, + .pd_alloc_fn = cfq_pd_alloc, .pd_init_fn = cfq_pd_init, .pd_offline_fn = cfq_pd_offline, + .pd_free_fn = cfq_pd_free, .pd_reset_stats_fn = cfq_pd_reset_stats, }; #endif |