From 41d7db0ab437bc84f8a6e77cccc626ce937605ac Mon Sep 17 00:00:00 2001 From: Steven Whitehouse Date: Mon, 14 May 2007 17:43:26 +0100 Subject: [PATCH] [GFS2] Reduce size of struct gdlm_lock This patch removes the completion (which is rather large) from struct gdlm_lock in favour of using the wait_on_bit() functions. We don't need to add any extra fields to the structure to do this, so we save 32 bytes (on x86_64) per structure. This adds up to quite a lot when we may potentially have millions of these lock structures, Signed-off-by: Steven Whitehouse Acked-by: David Teigland --- fs/gfs2/locking/dlm/lock.c | 11 ++++++++--- fs/gfs2/locking/dlm/lock_dlm.h | 2 +- fs/gfs2/locking/dlm/thread.c | 11 +++++++++-- 3 files changed, 18 insertions(+), 6 deletions(-) diff --git a/fs/gfs2/locking/dlm/lock.c b/fs/gfs2/locking/dlm/lock.c index c305255bfe8..542a797ac89 100644 --- a/fs/gfs2/locking/dlm/lock.c +++ b/fs/gfs2/locking/dlm/lock.c @@ -174,7 +174,6 @@ static int gdlm_create_lp(struct gdlm_ls *ls, struct lm_lockname *name, lp->cur = DLM_LOCK_IV; lp->lvb = NULL; lp->hold_null = NULL; - init_completion(&lp->ast_wait); INIT_LIST_HEAD(&lp->clist); INIT_LIST_HEAD(&lp->blist); INIT_LIST_HEAD(&lp->delay_list); @@ -399,6 +398,12 @@ static void gdlm_del_lvb(struct gdlm_lock *lp) lp->lksb.sb_lvbptr = NULL; } +static int gdlm_ast_wait(void *word) +{ + schedule(); + return 0; +} + /* This can do a synchronous dlm request (requiring a lock_dlm thread to get the completion) because gfs won't call hold_lvb() during a callback (from the context of a lock_dlm thread). */ @@ -424,10 +429,10 @@ static int hold_null_lock(struct gdlm_lock *lp) lpn->lkf = DLM_LKF_VALBLK | DLM_LKF_EXPEDITE; set_bit(LFL_NOBAST, &lpn->flags); set_bit(LFL_INLOCK, &lpn->flags); + set_bit(LFL_AST_WAIT, &lpn->flags); - init_completion(&lpn->ast_wait); gdlm_do_lock(lpn); - wait_for_completion(&lpn->ast_wait); + wait_on_bit(&lpn->flags, LFL_AST_WAIT, gdlm_ast_wait, TASK_UNINTERRUPTIBLE); error = lpn->lksb.sb_status; if (error) { printk(KERN_INFO "lock_dlm: hold_null_lock dlm error %d\n", diff --git a/fs/gfs2/locking/dlm/lock_dlm.h b/fs/gfs2/locking/dlm/lock_dlm.h index d074c6e6f9b..24d70f73b65 100644 --- a/fs/gfs2/locking/dlm/lock_dlm.h +++ b/fs/gfs2/locking/dlm/lock_dlm.h @@ -101,6 +101,7 @@ enum { LFL_NOBAST = 10, LFL_HEADQUE = 11, LFL_UNLOCK_DELETE = 12, + LFL_AST_WAIT = 13, }; struct gdlm_lock { @@ -117,7 +118,6 @@ struct gdlm_lock { unsigned long flags; /* lock_dlm flags LFL_ */ int bast_mode; /* protected by async_lock */ - struct completion ast_wait; struct list_head clist; /* complete */ struct list_head blist; /* blocking */ diff --git a/fs/gfs2/locking/dlm/thread.c b/fs/gfs2/locking/dlm/thread.c index 9cf1f168eaf..1aca51e4509 100644 --- a/fs/gfs2/locking/dlm/thread.c +++ b/fs/gfs2/locking/dlm/thread.c @@ -44,6 +44,13 @@ static void process_blocking(struct gdlm_lock *lp, int bast_mode) ls->fscb(ls->sdp, cb, &lp->lockname); } +static void wake_up_ast(struct gdlm_lock *lp) +{ + clear_bit(LFL_AST_WAIT, &lp->flags); + smp_mb__after_clear_bit(); + wake_up_bit(&lp->flags, LFL_AST_WAIT); +} + static void process_complete(struct gdlm_lock *lp) { struct gdlm_ls *ls = lp->ls; @@ -136,7 +143,7 @@ static void process_complete(struct gdlm_lock *lp) */ if (test_and_clear_bit(LFL_SYNC_LVB, &lp->flags)) { - complete(&lp->ast_wait); + wake_up_ast(lp); return; } @@ -214,7 +221,7 @@ out: if (test_bit(LFL_INLOCK, &lp->flags)) { clear_bit(LFL_NOBLOCK, &lp->flags); lp->cur = lp->req; - complete(&lp->ast_wait); + wake_up_ast(lp); return; } -- 2.39.5