| Message ID | 1519468562-68172-1-git-send-email-cgxu519@icloud.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
> On 24 Feb 2018, at 18:36, Chengguang Xu <cgxu519@icloud.com> wrote: > > When caps_avail_count is in a low level, most newly > trimmed caps will probably go into ->caps_list and > caps_avail_count will be increased. Hence after trimming, > should recheck caps_avail_count to effectly reuse > newly trimmed caps. Also, when releasing unnecessary > caps follow the same rule of ceph_put_cap. > > Signed-off-by: Chengguang Xu <cgxu519@icloud.com> > --- > Only compile tested. > > fs/ceph/caps.c | 41 +++++++++++++++++++++++++++++++++++++---- > 1 file changed, 37 insertions(+), 4 deletions(-) > > diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c > index 6582c45..ba58422 100644 > --- a/fs/ceph/caps.c > +++ b/fs/ceph/caps.c > @@ -165,6 +165,7 @@ int ceph_reserve_caps(struct ceph_mds_client *mdsc, > int have; > int alloc = 0; > int max_caps; > + int more_avail_caps; > bool trimmed = false; > struct ceph_mds_session *s; > LIST_HEAD(newcaps); > @@ -204,6 +205,24 @@ int ceph_reserve_caps(struct ceph_mds_client *mdsc, > mutex_lock(&mdsc->mutex); > } > trimmed = true; > + > + spin_lock(&mdsc->caps_list_lock); > + if (mdsc->caps_avail_count) { > + if (mdsc->caps_avail_count + have + alloc >= need) > + more_avail_caps = need - alloc - have; > + else > + more_avail_caps = mdsc->caps_avail_count; > + > + i += more_avail_caps; > + have += more_avail_caps; > + mdsc->caps_avail_count -= more_avail_caps; > + mdsc->caps_reserve_count += more_avail_caps; > + } > + spin_unlock(&mdsc->caps_list_lock); > + > + if (i >= need) > + break; > + > goto retry; > } else { > pr_warn("reserve caps ctx=%p ENOMEM " > @@ -234,16 +253,30 @@ int ceph_reserve_caps(struct ceph_mds_client *mdsc, > return 0; > > out_nomem: > + > + spin_lock(&mdsc->caps_list_lock); > + mdsc->caps_avail_count += have; > + mdsc->caps_reserve_count -= have; > + > while (!list_empty(&newcaps)) { > cap = list_first_entry(&newcaps, > struct ceph_cap, caps_item); > list_del(&cap->caps_item); > - kmem_cache_free(ceph_cap_cachep, cap); > + > + /* > + * Keep some preallocated caps around (ceph_min_count), to > + * avoid lots of free/alloc churn. > + */ > + if (mdsc->caps_avail_count >= mdsc->caps_reserve_count + > + mdsc->caps_min_count) { > + kmem_cache_free(ceph_cap_cachep, cap); > + } else { > + mdsc->caps_avail_count++; > + mdsc->caps_total_count++; > + list_add(&cap->caps_item, &mdsc->caps_list); > + } > } > > - spin_lock(&mdsc->caps_list_lock); > - mdsc->caps_avail_count += have; > - mdsc->caps_reserve_count -= have; > BUG_ON(mdsc->caps_total_count != mdsc->caps_use_count + > mdsc->caps_reserve_count + > mdsc->caps_avail_count); > -- > 1.8.3.1 Some lines exceed 80 characters. I make some modification to patch. Regards Yan, Zheng > -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
> 在 2018年3月5日，上午11:05，Yan, Zheng <zyan@redhat.com> 写道： > > > >> On 24 Feb 2018, at 18:36, Chengguang Xu <cgxu519@icloud.com> wrote: >> >> When caps_avail_count is in a low level, most newly >> trimmed caps will probably go into ->caps_list and >> caps_avail_count will be increased. Hence after trimming, >> should recheck caps_avail_count to effectly reuse >> newly trimmed caps. Also, when releasing unnecessary >> caps follow the same rule of ceph_put_cap. >> >> Signed-off-by: Chengguang Xu <cgxu519@icloud.com> >> --- >> Only compile tested. >> >> fs/ceph/caps.c | 41 +++++++++++++++++++++++++++++++++++++---- >> 1 file changed, 37 insertions(+), 4 deletions(-) >> >> diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c >> index 6582c45..ba58422 100644 >> --- a/fs/ceph/caps.c >> +++ b/fs/ceph/caps.c >> @@ -165,6 +165,7 @@ int ceph_reserve_caps(struct ceph_mds_client *mdsc, >> int have; >> int alloc = 0; >> int max_caps; >> + int more_avail_caps; >> bool trimmed = false; >> struct ceph_mds_session *s; >> LIST_HEAD(newcaps); >> @@ -204,6 +205,24 @@ int ceph_reserve_caps(struct ceph_mds_client *mdsc, >> mutex_lock(&mdsc->mutex); >> } >> trimmed = true; >> + >> + spin_lock(&mdsc->caps_list_lock); >> + if (mdsc->caps_avail_count) { >> + if (mdsc->caps_avail_count + have + alloc >= need) >> + more_avail_caps = need - alloc - have; >> + else >> + more_avail_caps = mdsc->caps_avail_count; >> + >> + i += more_avail_caps; >> + have += more_avail_caps; >> + mdsc->caps_avail_count -= more_avail_caps; >> + mdsc->caps_reserve_count += more_avail_caps; >> + } >> + spin_unlock(&mdsc->caps_list_lock); >> + >> + if (i >= need) >> + break; >> + >> goto retry; >> } else { >> pr_warn("reserve caps ctx=%p ENOMEM " >> @@ -234,16 +253,30 @@ int ceph_reserve_caps(struct ceph_mds_client *mdsc, >> return 0; >> >> out_nomem: >> + >> + spin_lock(&mdsc->caps_list_lock); >> + mdsc->caps_avail_count += have; >> + mdsc->caps_reserve_count -= have; >> + >> while (!list_empty(&newcaps)) { >> cap = list_first_entry(&newcaps, >> struct ceph_cap, caps_item); >> list_del(&cap->caps_item); >> - kmem_cache_free(ceph_cap_cachep, cap); >> + >> + /* >> + * Keep some preallocated caps around (ceph_min_count), to >> + * avoid lots of free/alloc churn. >> + */ >> + if (mdsc->caps_avail_count >= mdsc->caps_reserve_count + >> + mdsc->caps_min_count) { >> + kmem_cache_free(ceph_cap_cachep, cap); >> + } else { >> + mdsc->caps_avail_count++; >> + mdsc->caps_total_count++; >> + list_add(&cap->caps_item, &mdsc->caps_list); >> + } >> } >> >> - spin_lock(&mdsc->caps_list_lock); >> - mdsc->caps_avail_count += have; >> - mdsc->caps_reserve_count -= have; >> BUG_ON(mdsc->caps_total_count != mdsc->caps_use_count + >> mdsc->caps_reserve_count + >> mdsc->caps_avail_count); >> -- >> 1.8.3.1 > > Some lines exceed 80 characters. I make some modification to patch. I’ll put more attention on it next time. Thanks, Chengguang. -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c index 6582c45..ba58422 100644 --- a/fs/ceph/caps.c +++ b/fs/ceph/caps.c @@ -165,6 +165,7 @@ int ceph_reserve_caps(struct ceph_mds_client *mdsc, int have; int alloc = 0; int max_caps; + int more_avail_caps; bool trimmed = false; struct ceph_mds_session *s; LIST_HEAD(newcaps); @@ -204,6 +205,24 @@ int ceph_reserve_caps(struct ceph_mds_client *mdsc, mutex_lock(&mdsc->mutex); } trimmed = true; + + spin_lock(&mdsc->caps_list_lock); + if (mdsc->caps_avail_count) { + if (mdsc->caps_avail_count + have + alloc >= need) + more_avail_caps = need - alloc - have; + else + more_avail_caps = mdsc->caps_avail_count; + + i += more_avail_caps; + have += more_avail_caps; + mdsc->caps_avail_count -= more_avail_caps; + mdsc->caps_reserve_count += more_avail_caps; + } + spin_unlock(&mdsc->caps_list_lock); + + if (i >= need) + break; + goto retry; } else { pr_warn("reserve caps ctx=%p ENOMEM " @@ -234,16 +253,30 @@ int ceph_reserve_caps(struct ceph_mds_client *mdsc, return 0; out_nomem: + + spin_lock(&mdsc->caps_list_lock); + mdsc->caps_avail_count += have; + mdsc->caps_reserve_count -= have; + while (!list_empty(&newcaps)) { cap = list_first_entry(&newcaps, struct ceph_cap, caps_item); list_del(&cap->caps_item); - kmem_cache_free(ceph_cap_cachep, cap); + + /* + * Keep some preallocated caps around (ceph_min_count), to + * avoid lots of free/alloc churn. + */ + if (mdsc->caps_avail_count >= mdsc->caps_reserve_count + + mdsc->caps_min_count) { + kmem_cache_free(ceph_cap_cachep, cap); + } else { + mdsc->caps_avail_count++; + mdsc->caps_total_count++; + list_add(&cap->caps_item, &mdsc->caps_list); + } } - spin_lock(&mdsc->caps_list_lock); - mdsc->caps_avail_count += have; - mdsc->caps_reserve_count -= have; BUG_ON(mdsc->caps_total_count != mdsc->caps_use_count + mdsc->caps_reserve_count + mdsc->caps_avail_count);
When caps_avail_count is in a low level, most newly trimmed caps will probably go into ->caps_list and caps_avail_count will be increased. Hence after trimming, should recheck caps_avail_count to effectly reuse newly trimmed caps. Also, when releasing unnecessary caps follow the same rule of ceph_put_cap. Signed-off-by: Chengguang Xu <cgxu519@icloud.com> --- Only compile tested. fs/ceph/caps.c | 41 +++++++++++++++++++++++++++++++++++++---- 1 file changed, 37 insertions(+), 4 deletions(-)