Print this page
3742 zfs comments need cleaner, more consistent style
Submitted by:   Will Andrews <willa@spectralogic.com>
Submitted by:   Alan Somers <alans@spectralogic.com>
Reviewed by:    Matthew Ahrens <mahrens@delphix.com>
Reviewed by:    George Wilson <george.wilson@delphix.com>
Reviewed by:    Eric Schrock <eric.schrock@delphix.com>


  19  * CDDL HEADER END
  20  */
  21 /*
  22  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
  23  * Use is subject to license terms.
  24  */
  25 
  26 /*
  27  * Copyright (c) 2012 by Delphix. All rights reserved.
  28  */
  29 
  30 #include <sys/zfs_context.h>
  31 #include <sys/vdev_impl.h>
  32 #include <sys/spa_impl.h>
  33 #include <sys/zio.h>
  34 #include <sys/avl.h>
  35 
  36 /*
  37  * These tunables are for performance analysis.
  38  */




  39 /*
  40  * zfs_vdev_max_pending is the maximum number of i/os concurrently
  41  * pending to each device.  zfs_vdev_min_pending is the initial number
  42  * of i/os pending to each device (before it starts ramping up to
  43  * max_pending).
  44  */
  45 int zfs_vdev_max_pending = 10;
  46 int zfs_vdev_min_pending = 4;
  47 
  48 /*
  49  * The deadlines are grouped into buckets based on zfs_vdev_time_shift:
  50  * deadline = pri + gethrtime() >> time_shift)
  51  */
  52 int zfs_vdev_time_shift = 29; /* each bucket is 0.537 seconds */
  53 
  54 /* exponential I/O issue ramp-up rate */
  55 int zfs_vdev_ramp_rate = 2;
  56 
  57 /*
  58  * To reduce IOPs, we aggregate small adjacent I/Os into one large I/O.
  59  * For read I/Os, we also aggregate across small adjacency gaps; for writes
  60  * we include spans of optional I/Os to aid aggregation at the disk even when
  61  * they aren't able to help us aggregate at this level.
  62  */
  63 int zfs_vdev_aggregation_limit = SPA_MAXBLOCKSIZE;
  64 int zfs_vdev_read_gap_limit = 32 << 10;
  65 int zfs_vdev_write_gap_limit = 4 << 10;




  19  * CDDL HEADER END
  20  */
  21 /*
  22  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
  23  * Use is subject to license terms.
  24  */
  25 
  26 /*
  27  * Copyright (c) 2012 by Delphix. All rights reserved.
  28  */
  29 
  30 #include <sys/zfs_context.h>
  31 #include <sys/vdev_impl.h>
  32 #include <sys/spa_impl.h>
  33 #include <sys/zio.h>
  34 #include <sys/avl.h>
  35 
  36 /*
  37  * These tunables are for performance analysis.
  38  */
  39 
  40 /* The maximum number of I/Os concurrently pending to each device. */
  41 int zfs_vdev_max_pending = 10;
  42 
  43 /*
  44  * The initial number of I/Os pending to each device, before it starts ramping
  45  * up to zfs_vdev_max_pending.


  46  */

  47 int zfs_vdev_min_pending = 4;
  48 
  49 /*
  50  * The deadlines are grouped into buckets based on zfs_vdev_time_shift:
  51  * deadline = pri + gethrtime() >> time_shift)
  52  */
  53 int zfs_vdev_time_shift = 29; /* each bucket is 0.537 seconds */
  54 
  55 /* exponential I/O issue ramp-up rate */
  56 int zfs_vdev_ramp_rate = 2;
  57 
  58 /*
  59  * To reduce IOPs, we aggregate small adjacent I/Os into one large I/O.
  60  * For read I/Os, we also aggregate across small adjacency gaps; for writes
  61  * we include spans of optional I/Os to aid aggregation at the disk even when
  62  * they aren't able to help us aggregate at this level.
  63  */
  64 int zfs_vdev_aggregation_limit = SPA_MAXBLOCKSIZE;
  65 int zfs_vdev_read_gap_limit = 32 << 10;
  66 int zfs_vdev_write_gap_limit = 4 << 10;