kernel-ark/fs/xfs/xfs_trans_extfree.c
David Chinner da353b0d64 [XFS] Radix tree based inode caching
One of the perpetual scaling problems XFS has is indexing it's incore
inodes. We currently uses hashes and the default hash sizes chosen can
only ever be a tradeoff between memory consumption and the maximum
realistic size of the cache.

As a result, anyone who has millions of inodes cached on a filesystem
needs to tunes the size of the cache via the ihashsize mount option to
allow decent scalability with inode cache operations.

A further problem is the separate inode cluster hash, whose size is based
on the ihashsize but is smaller, and so under certain conditions (sparse
cluster cache population) this can become a limitation long before the
inode hash is causing issues.

The following patchset removes the inode hash and cluster hash and
replaces them with radix trees to avoid the scalability limitations of the
hashes. It also reduces the size of the inodes by 3 pointers....

SGI-PV: 969561
SGI-Modid: xfs-linux-melb:xfs-kern:29481a

Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Tim Shimmin <tes@sgi.com>
2007-10-15 16:50:50 +10:00

142 lines
3.6 KiB
C

/*
* Copyright (c) 2000,2005 Silicon Graphics, Inc.
* All Rights Reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it would be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "xfs.h"
#include "xfs_fs.h"
#include "xfs_types.h"
#include "xfs_log.h"
#include "xfs_inum.h"
#include "xfs_trans.h"
#include "xfs_sb.h"
#include "xfs_ag.h"
#include "xfs_dmapi.h"
#include "xfs_mount.h"
#include "xfs_trans_priv.h"
#include "xfs_extfree_item.h"
/*
* This routine is called to allocate an "extent free intention"
* log item that will hold nextents worth of extents. The
* caller must use all nextents extents, because we are not
* flexible about this at all.
*/
xfs_efi_log_item_t *
xfs_trans_get_efi(xfs_trans_t *tp,
uint nextents)
{
xfs_efi_log_item_t *efip;
ASSERT(tp != NULL);
ASSERT(nextents > 0);
efip = xfs_efi_init(tp->t_mountp, nextents);
ASSERT(efip != NULL);
/*
* Get a log_item_desc to point at the new item.
*/
(void) xfs_trans_add_item(tp, (xfs_log_item_t*)efip);
return (efip);
}
/*
* This routine is called to indicate that the described
* extent is to be logged as needing to be freed. It should
* be called once for each extent to be freed.
*/
void
xfs_trans_log_efi_extent(xfs_trans_t *tp,
xfs_efi_log_item_t *efip,
xfs_fsblock_t start_block,
xfs_extlen_t ext_len)
{
xfs_log_item_desc_t *lidp;
uint next_extent;
xfs_extent_t *extp;
lidp = xfs_trans_find_item(tp, (xfs_log_item_t*)efip);
ASSERT(lidp != NULL);
tp->t_flags |= XFS_TRANS_DIRTY;
lidp->lid_flags |= XFS_LID_DIRTY;
next_extent = efip->efi_next_extent;
ASSERT(next_extent < efip->efi_format.efi_nextents);
extp = &(efip->efi_format.efi_extents[next_extent]);
extp->ext_start = start_block;
extp->ext_len = ext_len;
efip->efi_next_extent++;
}
/*
* This routine is called to allocate an "extent free done"
* log item that will hold nextents worth of extents. The
* caller must use all nextents extents, because we are not
* flexible about this at all.
*/
xfs_efd_log_item_t *
xfs_trans_get_efd(xfs_trans_t *tp,
xfs_efi_log_item_t *efip,
uint nextents)
{
xfs_efd_log_item_t *efdp;
ASSERT(tp != NULL);
ASSERT(nextents > 0);
efdp = xfs_efd_init(tp->t_mountp, efip, nextents);
ASSERT(efdp != NULL);
/*
* Get a log_item_desc to point at the new item.
*/
(void) xfs_trans_add_item(tp, (xfs_log_item_t*)efdp);
return (efdp);
}
/*
* This routine is called to indicate that the described
* extent is to be logged as having been freed. It should
* be called once for each extent freed.
*/
void
xfs_trans_log_efd_extent(xfs_trans_t *tp,
xfs_efd_log_item_t *efdp,
xfs_fsblock_t start_block,
xfs_extlen_t ext_len)
{
xfs_log_item_desc_t *lidp;
uint next_extent;
xfs_extent_t *extp;
lidp = xfs_trans_find_item(tp, (xfs_log_item_t*)efdp);
ASSERT(lidp != NULL);
tp->t_flags |= XFS_TRANS_DIRTY;
lidp->lid_flags |= XFS_LID_DIRTY;
next_extent = efdp->efd_next_extent;
ASSERT(next_extent < efdp->efd_format.efd_nextents);
extp = &(efdp->efd_format.efd_extents[next_extent]);
extp->ext_start = start_block;
extp->ext_len = ext_len;
efdp->efd_next_extent++;
}