3699e3a44b
This removes the extra filldir callback which gfs2 was using to enclose an attempt at readahead for inodes during readdir. The code was too complicated and also hurts performance badly in the case that the getdents64/readdir call isn't being followed by stat() and it wasn't even getting it right all the time when it was. As a result, on my test box an "ls" of a directory containing 250000 files fell from about 7mins (freshly mounted, so nothing cached) to between about 15 to 25 seconds. When the directory content was cached, the time taken fell from about 3mins to about 4 or 5 seconds. Interestingly in the cached case, running "ls -l" once reduced the time taken for subsequent runs of "ls" to about 6 secs even without this patch. Now it turns out that there was a special case of glocks being used for prefetching the metadata, but because of the timeouts for these locks (set to 10 secs) the metadata was being timed out before it was being used and this the prefetch code was constantly trying to prefetch the same data over and over. Calling "ls -l" meant that the inodes were brought into memory and once the inodes are cached, the glocks are not disposed of until the inodes are pushed out of the cache, thus extending the lifetime of the glocks, and thus bringing down the time for subsequent runs of "ls" considerably. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
147 lines
4.0 KiB
C
147 lines
4.0 KiB
C
/*
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* Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
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* Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
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*
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* This copyrighted material is made available to anyone wishing to use,
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* modify, copy, or redistribute it subject to the terms and conditions
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* of the GNU General Public License version 2.
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*/
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#ifndef __GLOCK_DOT_H__
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#define __GLOCK_DOT_H__
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#include "incore.h"
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/* Flags for lock requests; used in gfs2_holder gh_flag field.
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From lm_interface.h:
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#define LM_FLAG_TRY 0x00000001
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#define LM_FLAG_TRY_1CB 0x00000002
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#define LM_FLAG_NOEXP 0x00000004
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#define LM_FLAG_ANY 0x00000008
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#define LM_FLAG_PRIORITY 0x00000010 */
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#define GL_LOCAL_EXCL 0x00000020
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#define GL_ASYNC 0x00000040
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#define GL_EXACT 0x00000080
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#define GL_SKIP 0x00000100
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#define GL_ATIME 0x00000200
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#define GL_NOCACHE 0x00000400
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#define GL_NOCANCEL 0x00001000
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#define GLR_TRYFAILED 13
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#define GLR_CANCELED 14
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static inline int gfs2_glock_is_locked_by_me(struct gfs2_glock *gl)
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{
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struct gfs2_holder *gh;
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int locked = 0;
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/* Look in glock's list of holders for one with current task as owner */
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spin_lock(&gl->gl_spin);
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list_for_each_entry(gh, &gl->gl_holders, gh_list) {
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if (gh->gh_owner == current) {
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locked = 1;
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break;
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}
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}
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spin_unlock(&gl->gl_spin);
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return locked;
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}
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static inline int gfs2_glock_is_held_excl(struct gfs2_glock *gl)
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{
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return gl->gl_state == LM_ST_EXCLUSIVE;
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}
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static inline int gfs2_glock_is_held_dfrd(struct gfs2_glock *gl)
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{
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return gl->gl_state == LM_ST_DEFERRED;
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}
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static inline int gfs2_glock_is_held_shrd(struct gfs2_glock *gl)
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{
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return gl->gl_state == LM_ST_SHARED;
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}
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static inline int gfs2_glock_is_blocking(struct gfs2_glock *gl)
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{
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int ret;
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spin_lock(&gl->gl_spin);
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ret = !list_empty(&gl->gl_waiters2) || !list_empty(&gl->gl_waiters3);
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spin_unlock(&gl->gl_spin);
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return ret;
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}
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int gfs2_glock_get(struct gfs2_sbd *sdp,
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u64 number, const struct gfs2_glock_operations *glops,
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int create, struct gfs2_glock **glp);
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void gfs2_glock_hold(struct gfs2_glock *gl);
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int gfs2_glock_put(struct gfs2_glock *gl);
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void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state, unsigned flags,
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struct gfs2_holder *gh);
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void gfs2_holder_reinit(unsigned int state, unsigned flags,
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struct gfs2_holder *gh);
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void gfs2_holder_uninit(struct gfs2_holder *gh);
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void gfs2_glock_xmote_th(struct gfs2_glock *gl, unsigned int state, int flags);
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void gfs2_glock_drop_th(struct gfs2_glock *gl);
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int gfs2_glock_nq(struct gfs2_holder *gh);
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int gfs2_glock_poll(struct gfs2_holder *gh);
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int gfs2_glock_wait(struct gfs2_holder *gh);
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void gfs2_glock_dq(struct gfs2_holder *gh);
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int gfs2_glock_be_greedy(struct gfs2_glock *gl, unsigned int time);
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void gfs2_glock_dq_uninit(struct gfs2_holder *gh);
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int gfs2_glock_nq_num(struct gfs2_sbd *sdp,
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u64 number, const struct gfs2_glock_operations *glops,
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unsigned int state, int flags, struct gfs2_holder *gh);
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int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs);
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void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs);
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void gfs2_glock_dq_uninit_m(unsigned int num_gh, struct gfs2_holder *ghs);
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/**
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* gfs2_glock_nq_init - intialize a holder and enqueue it on a glock
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* @gl: the glock
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* @state: the state we're requesting
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* @flags: the modifier flags
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* @gh: the holder structure
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*
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* Returns: 0, GLR_*, or errno
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*/
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static inline int gfs2_glock_nq_init(struct gfs2_glock *gl,
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unsigned int state, int flags,
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struct gfs2_holder *gh)
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{
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int error;
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gfs2_holder_init(gl, state, flags, gh);
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error = gfs2_glock_nq(gh);
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if (error)
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gfs2_holder_uninit(gh);
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return error;
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}
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/* Lock Value Block functions */
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int gfs2_lvb_hold(struct gfs2_glock *gl);
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void gfs2_lvb_unhold(struct gfs2_glock *gl);
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void gfs2_glock_cb(void *cb_data, unsigned int type, void *data);
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void gfs2_glock_schedule_for_reclaim(struct gfs2_glock *gl);
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void gfs2_reclaim_glock(struct gfs2_sbd *sdp);
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void gfs2_scand_internal(struct gfs2_sbd *sdp);
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void gfs2_gl_hash_clear(struct gfs2_sbd *sdp, int wait);
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int __init gfs2_glock_init(void);
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#endif /* __GLOCK_DOT_H__ */
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