[GFS2] Remove the "greedy" function from glock.[ch]

The "greedy" code was an attempt to retain glocks for a minimum length
of time when they relate to mmap()ed files. The current implementation
of this feature is not, however, ideal in that it required allocating
memory in order to do this and its overly complicated.

It also misses the mark by ignoring the other I/O operations which are
just as likely to suffer from the same problem. So the plan is to remove
this now and then add the functionality back as part of the glock state
machine at a later date (and thus take into account all the possible
users of this feature)

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c
index 5341e03b873f6fb04d9f3912f773ea07111afb47..90847e0957bbb8e2d9bc5642af5108dbc31e4bdc 100644 (file)
--- a/fs/gfs2/glock.c
+++ b/fs/gfs2/glock.c
@@ -34,11 +34,6 @@
 #include "super.h"
 #include "util.h"
 
-struct greedy {
-       struct gfs2_holder gr_gh;
-       struct delayed_work gr_work;
-};
-
 struct gfs2_gl_hash_bucket {
         struct hlist_head hb_list;
 };
@@ -617,30 +612,6 @@ static int rq_demote(struct gfs2_holder *gh)
        return 0;
 }
 
-/**
- * rq_greedy - process a queued request to drop greedy status
- * @gh: the glock holder
- *
- * Returns: 1 if the queue is blocked
- */
-
-static int rq_greedy(struct gfs2_holder *gh)
-{
-       struct gfs2_glock *gl = gh->gh_gl;
-
-       list_del_init(&gh->gh_list);
-       /*  gh->gh_error never examined.  */
-       clear_bit(GLF_GREEDY, &gl->gl_flags);
-       spin_unlock(&gl->gl_spin);
-
-       gfs2_holder_uninit(gh);
-       kfree(container_of(gh, struct greedy, gr_gh));
-
-       spin_lock(&gl->gl_spin);
-
-       return 0;
-}
-
 /**
  * run_queue - process holder structures on a glock
  * @gl: the glock
@@ -671,8 +642,6 @@ static void run_queue(struct gfs2_glock *gl)
 
                        if (test_bit(HIF_DEMOTE, &gh->gh_iflags))
                                blocked = rq_demote(gh);
-                       else if (test_bit(HIF_GREEDY, &gh->gh_iflags))
-                               blocked = rq_greedy(gh);
                        else
                                gfs2_assert_warn(gl->gl_sbd, 0);
 
@@ -1336,68 +1305,6 @@ void gfs2_glock_dq(struct gfs2_holder *gh)
        spin_unlock(&gl->gl_spin);
 }
 
-static void greedy_work(struct work_struct *work)
-{
-       struct greedy *gr = container_of(work, struct greedy, gr_work.work);
-       struct gfs2_holder *gh = &gr->gr_gh;
-       struct gfs2_glock *gl = gh->gh_gl;
-       const struct gfs2_glock_operations *glops = gl->gl_ops;
-
-       clear_bit(GLF_SKIP_WAITERS2, &gl->gl_flags);
-
-       if (glops->go_greedy)
-               glops->go_greedy(gl);
-
-       spin_lock(&gl->gl_spin);
-
-       if (list_empty(&gl->gl_waiters2)) {
-               clear_bit(GLF_GREEDY, &gl->gl_flags);
-               spin_unlock(&gl->gl_spin);
-               gfs2_holder_uninit(gh);
-               kfree(gr);
-       } else {
-               gfs2_glock_hold(gl);
-               list_add_tail(&gh->gh_list, &gl->gl_waiters2);
-               run_queue(gl);
-               spin_unlock(&gl->gl_spin);
-               gfs2_glock_put(gl);
-       }
-}
-
-/**
- * gfs2_glock_be_greedy -
- * @gl:
- * @time:
- *
- * Returns: 0 if go_greedy will be called, 1 otherwise
- */
-
-int gfs2_glock_be_greedy(struct gfs2_glock *gl, unsigned int time)
-{
-       struct greedy *gr;
-       struct gfs2_holder *gh;
-
-       if (!time || gl->gl_sbd->sd_args.ar_localcaching ||
-           test_and_set_bit(GLF_GREEDY, &gl->gl_flags))
-               return 1;
-
-       gr = kmalloc(sizeof(struct greedy), GFP_KERNEL);
-       if (!gr) {
-               clear_bit(GLF_GREEDY, &gl->gl_flags);
-               return 1;
-       }
-       gh = &gr->gr_gh;
-
-       gfs2_holder_init(gl, 0, 0, gh);
-       set_bit(HIF_GREEDY, &gh->gh_iflags);
-       INIT_DELAYED_WORK(&gr->gr_work, greedy_work);
-
-       set_bit(GLF_SKIP_WAITERS2, &gl->gl_flags);
-       schedule_delayed_work(&gr->gr_work, time);
-
-       return 0;
-}
-
 /**
  * gfs2_glock_dq_uninit - dequeue a holder from a glock and initialize it
  * @gh: the holder structure

diff --git a/fs/gfs2/glock.h b/fs/gfs2/glock.h
index bde02a7061ecd35c3905f2abd4f78539e3c81899..ddc56dc4ec9fe59d4902d323e8458d253edb7073 100644 (file)
--- a/fs/gfs2/glock.h
+++ b/fs/gfs2/glock.h
@@ -92,8 +92,6 @@ int gfs2_glock_poll(struct gfs2_holder *gh);
 int gfs2_glock_wait(struct gfs2_holder *gh);
 void gfs2_glock_dq(struct gfs2_holder *gh);
 
-int gfs2_glock_be_greedy(struct gfs2_glock *gl, unsigned int time);
-
 void gfs2_glock_dq_uninit(struct gfs2_holder *gh);
 int gfs2_glock_nq_num(struct gfs2_sbd *sdp,
                      u64 number, const struct gfs2_glock_operations *glops,

diff --git a/fs/gfs2/glops.c b/fs/gfs2/glops.c
index b068d10bcb6e75b981eef0b977cd4ca912743960..e4da26fe406fa05feaf7e71563c71aa6464a3489 100644 (file)
--- a/fs/gfs2/glops.c
+++ b/fs/gfs2/glops.c
@@ -318,39 +318,6 @@ static void inode_go_unlock(struct gfs2_holder *gh)
                gfs2_meta_cache_flush(ip);
 }
 
-/**
- * inode_greedy -
- * @gl: the glock
- *
- */
-
-static void inode_greedy(struct gfs2_glock *gl)
-{
-       struct gfs2_sbd *sdp = gl->gl_sbd;
-       struct gfs2_inode *ip = gl->gl_object;
-       unsigned int quantum = gfs2_tune_get(sdp, gt_greedy_quantum);
-       unsigned int max = gfs2_tune_get(sdp, gt_greedy_max);
-       unsigned int new_time;
-
-       spin_lock(&ip->i_spin);
-
-       if (time_after(ip->i_last_pfault + quantum, jiffies)) {
-               new_time = ip->i_greedy + quantum;
-               if (new_time > max)
-                       new_time = max;
-       } else {
-               new_time = ip->i_greedy - quantum;
-               if (!new_time || new_time > max)
-                       new_time = 1;
-       }
-
-       ip->i_greedy = new_time;
-
-       spin_unlock(&ip->i_spin);
-
-       iput(&ip->i_inode);
-}
-
 /**
  * rgrp_go_demote_ok - Check to see if it's ok to unlock a RG's glock
  * @gl: the glock
@@ -492,7 +459,6 @@ const struct gfs2_glock_operations gfs2_inode_glops = {
        .go_demote_ok = inode_go_demote_ok,
        .go_lock = inode_go_lock,
        .go_unlock = inode_go_unlock,
-       .go_greedy = inode_greedy,
        .go_type = LM_TYPE_INODE,
 };
 

diff --git a/fs/gfs2/incore.h b/fs/gfs2/incore.h
index a24c4af09ce08c61f0f7434cf643e67383b3619b..dc024b18ea9649016ce22e90e24748a24303e1a5 100644 (file)
--- a/fs/gfs2/incore.h
+++ b/fs/gfs2/incore.h
@@ -111,7 +111,6 @@ struct gfs2_glock_operations {
        int (*go_lock) (struct gfs2_holder *gh);
        void (*go_unlock) (struct gfs2_holder *gh);
        void (*go_callback) (struct gfs2_glock *gl, unsigned int state);
-       void (*go_greedy) (struct gfs2_glock *gl);
        const int go_type;
 };
 
@@ -120,7 +119,6 @@ enum {
        HIF_MUTEX               = 0,
        HIF_PROMOTE             = 1,
        HIF_DEMOTE              = 2,
-       HIF_GREEDY              = 3,
 
        /* States */
        HIF_ALLOCED             = 4,
@@ -149,7 +147,6 @@ enum {
        GLF_STICKY              = 2,
        GLF_DIRTY               = 5,
        GLF_SKIP_WAITERS2       = 6,
-       GLF_GREEDY              = 7,
 };
 
 struct gfs2_glock {
@@ -166,7 +163,7 @@ struct gfs2_glock {
        unsigned long gl_ip;
        struct list_head gl_holders;
        struct list_head gl_waiters1;   /* HIF_MUTEX */
-       struct list_head gl_waiters2;   /* HIF_DEMOTE, HIF_GREEDY */
+       struct list_head gl_waiters2;   /* HIF_DEMOTE */
        struct list_head gl_waiters3;   /* HIF_PROMOTE */
 
        const struct gfs2_glock_operations *gl_ops;
@@ -235,7 +232,6 @@ struct gfs2_inode {
 
        spinlock_t i_spin;
        struct rw_semaphore i_rw_mutex;
-       unsigned int i_greedy;
        unsigned long i_last_pfault;
 
        struct buffer_head *i_cache[GFS2_MAX_META_HEIGHT];
@@ -423,9 +419,6 @@ struct gfs2_tune {
        unsigned int gt_complain_secs;
        unsigned int gt_reclaim_limit; /* Max num of glocks in reclaim list */
        unsigned int gt_entries_per_readdir;
-       unsigned int gt_greedy_default;
-       unsigned int gt_greedy_quantum;
-       unsigned int gt_greedy_max;
        unsigned int gt_statfs_quantum;
        unsigned int gt_statfs_slow;
 };

diff --git a/fs/gfs2/ops_super.c b/fs/gfs2/ops_super.c
index c22738cdbf2dc2a18c8adc6e49fddcda1b2d8d11..47369d0112147d8c7fb814234bf2f4cd9bdd80e4 100644 (file)
--- a/fs/gfs2/ops_super.c
+++ b/fs/gfs2/ops_super.c
@@ -452,14 +452,12 @@ out:
 
 static struct inode *gfs2_alloc_inode(struct super_block *sb)
 {
-       struct gfs2_sbd *sdp = sb->s_fs_info;
        struct gfs2_inode *ip;
 
        ip = kmem_cache_alloc(gfs2_inode_cachep, GFP_KERNEL);
        if (ip) {
                ip->i_flags = 0;
                ip->i_gl = NULL;
-               ip->i_greedy = gfs2_tune_get(sdp, gt_greedy_default);
                ip->i_last_pfault = jiffies;
        }
        return &ip->i_inode;

diff --git a/fs/gfs2/ops_vm.c b/fs/gfs2/ops_vm.c
index 45a5f11fc39a88b0a53953e590cae739c4ad920b..14b380fb060290a77f24a96872e8b6b439707128 100644 (file)
--- a/fs/gfs2/ops_vm.c
+++ b/fs/gfs2/ops_vm.c
@@ -28,34 +28,13 @@
 #include "trans.h"
 #include "util.h"
 
-static void pfault_be_greedy(struct gfs2_inode *ip)
-{
-       unsigned int time;
-
-       spin_lock(&ip->i_spin);
-       time = ip->i_greedy;
-       ip->i_last_pfault = jiffies;
-       spin_unlock(&ip->i_spin);
-
-       igrab(&ip->i_inode);
-       if (gfs2_glock_be_greedy(ip->i_gl, time))
-               iput(&ip->i_inode);
-}
-
 static struct page *gfs2_private_nopage(struct vm_area_struct *area,
                                        unsigned long address, int *type)
 {
        struct gfs2_inode *ip = GFS2_I(area->vm_file->f_mapping->host);
-       struct page *result;
 
        set_bit(GIF_PAGED, &ip->i_flags);
-
-       result = filemap_nopage(area, address, type);
-
-       if (result && result != NOPAGE_OOM)
-               pfault_be_greedy(ip);
-
-       return result;
+       return filemap_nopage(area, address, type);
 }
 
 static int alloc_page_backing(struct gfs2_inode *ip, struct page *page)
@@ -167,7 +146,6 @@ static struct page *gfs2_sharewrite_nopage(struct vm_area_struct *area,
                set_page_dirty(result);
        }
 
-       pfault_be_greedy(ip);
 out:
        gfs2_glock_dq_uninit(&i_gh);
 

diff --git a/fs/gfs2/super.c b/fs/gfs2/super.c
index 3e17dcf35a30965490b48bb498e9f928c63cc3c8..ce5353ac8f3dfdde8ff402371ae9780f72e8e3d7 100644 (file)
--- a/fs/gfs2/super.c
+++ b/fs/gfs2/super.c
@@ -77,9 +77,6 @@ void gfs2_tune_init(struct gfs2_tune *gt)
        gt->gt_complain_secs = 10;
        gt->gt_reclaim_limit = 5000;
        gt->gt_entries_per_readdir = 32;
-       gt->gt_greedy_default = HZ / 10;
-       gt->gt_greedy_quantum = HZ / 40;
-       gt->gt_greedy_max = HZ / 4;
        gt->gt_statfs_quantum = 30;
        gt->gt_statfs_slow = 0;
 }

diff --git a/fs/gfs2/sys.c b/fs/gfs2/sys.c
index 11206118d983693a6980e7676fc5b04a4d66c2ea..d01f9f0fda261de2b95cff57353b0f8ca44ff79e 100644 (file)
--- a/fs/gfs2/sys.c
+++ b/fs/gfs2/sys.c
@@ -442,9 +442,6 @@ TUNE_ATTR(new_files_directio, 0);
 TUNE_ATTR(quota_simul_sync, 1);
 TUNE_ATTR(quota_cache_secs, 1);
 TUNE_ATTR(stall_secs, 1);
-TUNE_ATTR(greedy_default, 1);
-TUNE_ATTR(greedy_quantum, 1);
-TUNE_ATTR(greedy_max, 1);
 TUNE_ATTR(statfs_quantum, 1);
 TUNE_ATTR_DAEMON(scand_secs, scand_process);
 TUNE_ATTR_DAEMON(recoverd_secs, recoverd_process);
@@ -467,9 +464,6 @@ static struct attribute *tune_attrs[] = {
        &tune_attr_quota_simul_sync.attr,
        &tune_attr_quota_cache_secs.attr,
        &tune_attr_stall_secs.attr,
-       &tune_attr_greedy_default.attr,
-       &tune_attr_greedy_quantum.attr,
-       &tune_attr_greedy_max.attr,
        &tune_attr_statfs_quantum.attr,
        &tune_attr_scand_secs.attr,
        &tune_attr_recoverd_secs.attr,