From: Jinshan Xiong <jinshan.xi...@intel.com> Add new information about the fields in struct client_obd.
Signed-off-by: Jinshan Xiong <jinshan.xi...@intel.com> Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-5108 Reviewed-on: http://review.whamcloud.com/10458 Reviewed-by: Bobi Jam <bobi...@hotmail.com> Reviewed-by: Fan Yong <fan.y...@intel.com> Reviewed-by: Oleg Drokin <oleg.dro...@intel.com> Signed-off-by: James Simmons <jsimm...@infradead.org> --- drivers/staging/lustre/lustre/include/obd.h | 27 ++++++++++++++++++++++--- drivers/staging/lustre/lustre/osc/osc_page.c | 17 +++++++++++---- 2 files changed, 35 insertions(+), 9 deletions(-) diff --git a/drivers/staging/lustre/lustre/include/obd.h b/drivers/staging/lustre/lustre/include/obd.h index d4d2ffa..6d6e479 100644 --- a/drivers/staging/lustre/lustre/include/obd.h +++ b/drivers/staging/lustre/lustre/include/obd.h @@ -247,15 +247,34 @@ struct client_obd { struct obd_histogram cl_read_offset_hist; struct obd_histogram cl_write_offset_hist; - /* lru for osc caching pages */ + /* LRU for osc caching pages */ struct cl_client_cache *cl_cache; - struct list_head cl_lru_osc; /* member of cl_cache->ccc_lru */ + /** member of cl_cache->ccc_lru */ + struct list_head cl_lru_osc; + /** # of available LRU slots left in the per-OSC cache. + * Available LRU slots are shared by all OSCs of the same file system, + * therefore this is a pointer to cl_client_cache::ccc_lru_left. + */ atomic_long_t *cl_lru_left; + /** # of busy LRU pages. A page is considered busy if it's in writeback + * queue, or in transfer. Busy pages can't be discarded so they are not + * in LRU cache. + */ atomic_long_t cl_lru_busy; + /** # of LRU pages in the cache for this client_obd */ atomic_long_t cl_lru_in_list; + /** # of threads are shrinking LRU cache. To avoid contention, it's not + * allowed to have multiple threads shrinking LRU cache. + */ atomic_t cl_lru_shrinkers; - struct list_head cl_lru_list; /* lru page list */ - spinlock_t cl_lru_list_lock; /* page list protector */ + /** List of LRU pages for this client_obd */ + struct list_head cl_lru_list; + /** Lock for LRU page list */ + spinlock_t cl_lru_list_lock; + /** # of unstable pages in this client_obd. + * An unstable page is a page state that WRITE RPC has finished but + * the transaction has NOT yet committed. + */ atomic_long_t cl_unstable_count; /* number of in flight destroy rpcs is limited to max_rpcs_in_flight */ diff --git a/drivers/staging/lustre/lustre/osc/osc_page.c b/drivers/staging/lustre/lustre/osc/osc_page.c index 7a1f102..2cdc30a 100644 --- a/drivers/staging/lustre/lustre/osc/osc_page.c +++ b/drivers/staging/lustre/lustre/osc/osc_page.c @@ -343,16 +343,17 @@ void osc_page_submit(const struct lu_env *env, struct osc_page *opg, * OSC to free slots voluntarily to maintain a reasonable number of free slots * at any time. */ - static DECLARE_WAIT_QUEUE_HEAD(osc_lru_waitq); -/* LRU pages are freed in batch mode. OSC should at least free this - * number of pages to avoid running out of LRU budget, and.. + +/** + * LRU pages are freed in batch mode. OSC should at least free this + * number of pages to avoid running out of LRU slots. */ static const int lru_shrink_min = 2 << (20 - PAGE_SHIFT); /* 2M */ -/* free this number at most otherwise it will take too long time to finish. */ static const int lru_shrink_max = 8 << (20 - PAGE_SHIFT); /* 8M */ -/* Check if we can free LRU slots from this OSC. If there exists LRU waiters, +/** + * Check if we can free LRU slots from this OSC. If there exists LRU waiters, * we should free slots aggressively. In this way, slots are freed in a steady * step to maintain fairness among OSCs. * @@ -643,6 +644,12 @@ long osc_lru_shrink(const struct lu_env *env, struct client_obd *cli, return count > 0 ? count : rc; } +/** + * Reclaim LRU pages by an IO thread. The caller wants to reclaim at least + * \@npages of LRU slots. For performance consideration, it's better to drop + * LRU pages in batch. Therefore, the actual number is adjusted at least + * max_pages_per_rpc. + */ long osc_lru_reclaim(struct client_obd *cli) { struct lu_env *env; -- 1.7.1 _______________________________________________ devel mailing list de...@linuxdriverproject.org http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
