On 07/17/2011 11:04 PM, liubo wrote: > On 07/16/2011 02:29 AM, Josef Bacik wrote: >> Currently we reserve enough space to COW an entirely full btree for every >> extent >> we have reserved for an inode. This _sucks_, because you only need to COW >> once, >> and then everybody else is ok. Unfortunately we don't know we'll all be >> able to >> get into the same transaction so that's what we have had to do. But the >> global >> reserve holds a reservation large enough to cover a large percentage of all >> the >> metadata currently in the fs. So all we really need to account for is any >> new >> blocks that we may allocate. So fix this by >> >> 1) Passing to btrfs_alloc_free_block() wether this is a new block or a COW >> block. If it is a COW block we use the global reserve, if not we use the >> trans->block_rsv. >> 2) Reduce the amount of space we reserve. Since we don't need to account for >> cow'ing the tree we can just keep track of new blocks to reserve, which >> greatly >> reduces the reservation amount. >> >> This makes my basic random write test go from 3 mb/s to 75 mb/s. I've tested >> this with my horrible ENOSPC test and it seems to work out fine. Thanks, >> > > Hi, Josef, > > After I patched this and did a "tar xf source.tar", I got lots of warnings, > > Would you like to look into this? > > ------------[ cut here ]------------ > WARNING: at fs/btrfs/extent-tree.c:5695 btrfs_alloc_free_block+0x178/0x340 > [btrfs]() > Hardware name: QiTianM7150 > Modules linked in: btrfs iptable_nat nf_nat zlib_deflate libcrc32c > ebtable_nat ebtables bridge stp llc cpufreq_ondemand acpi_cpufreq freq_table > mperf be2iscsi iscsi_boot_sysfs bnx2i cnic uio cxgb3i libcxgbi cxgb3 mdio > iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi ext3 jbd dm_mirror > dm_region_hash dm_log dm_mod sg ppdev serio_raw pcspkr i2c_i801 iTCO_wdt > iTCO_vendor_support sky2 parport_pc parport ext4 mbcache jbd2 sd_mod > crc_t10dif pata_acpi ata_generic ata_piix i915 drm_kms_helper drm > i2c_algo_bit i2c_core video [last unloaded: btrfs] > Pid: 16008, comm: umount Tainted: G W 2.6.39+ #9 > Call Trace: > [<ffffffff81053baf>] warn_slowpath_common+0x7f/0xc0 > [<ffffffff81053c0a>] warn_slowpath_null+0x1a/0x20 > [<ffffffffa04d37d8>] btrfs_alloc_free_block+0x178/0x340 [btrfs] > [<ffffffffa0501768>] ? read_extent_buffer+0xd8/0x1d0 [btrfs] > [<ffffffffa04be625>] __btrfs_cow_block+0x155/0x5f0 [btrfs] > [<ffffffffa04bebcb>] btrfs_cow_block+0x10b/0x240 [btrfs] > [<ffffffffa04c4c8e>] btrfs_search_slot+0x49e/0x7a0 [btrfs] > [<ffffffffa04d2399>] btrfs_write_dirty_block_groups+0x1a9/0x4d0 [btrfs] > [<ffffffffa0512e20>] ? btrfs_tree_unlock+0x50/0x50 [btrfs] > [<ffffffffa04df845>] commit_cowonly_roots+0x105/0x1e0 [btrfs] > [<ffffffffa04e0708>] btrfs_commit_transaction+0x428/0x850 [btrfs] > [<ffffffffa04df9b8>] ? wait_current_trans+0x28/0x100 [btrfs] > [<ffffffffa04e0c25>] ? join_transaction+0x25/0x250 [btrfs] > [<ffffffff81075590>] ? wake_up_bit+0x40/0x40 > [<ffffffffa04bb187>] btrfs_sync_fs+0x67/0xd0 [btrfs] > [<ffffffff8116c27e>] __sync_filesystem+0x5e/0x90 > [<ffffffff8116c38b>] sync_filesystem+0x4b/0x70 > [<ffffffff811441c4>] generic_shutdown_super+0x34/0xf0 > [<ffffffff81144316>] kill_anon_super+0x16/0x60 > [<ffffffff81144a25>] deactivate_locked_super+0x45/0x70 > [<ffffffff8114568a>] deactivate_super+0x4a/0x70 > [<ffffffff8115efdc>] mntput_no_expire+0x13c/0x1c0 > [<ffffffff8115f7bb>] sys_umount+0x7b/0x3a0 > [<ffffffff81466b2b>] system_call_fastpath+0x16/0x1b > ---[ end trace 9a65800674b03b84 ]--- >
Hmm, not reserving enough room for the chunk tree it seems, or I screwed something up and we're not using the right reserve. I will look into this, thanks, Josef -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
