FreeBSD src
19ea3d25df
The zil_itx_create() function uses the vmem_alloc() allocator for its buffers because when logging a write that buffer may be as large as 64K. This is non-optimal because we may need to allocate many of of these buffers and this interface has the potential to be slow. Instead, use zio_data_buf_alloc() which is specifically designed to be able to efficiently allocate a wide range of buffer sizes. In addition, do some cleanup and use the zil_itx_destroy() function to always free an itx structure. This way we're always sure the right allocation functions are used. Notice that in the current code kmem_free() and vmem_free() were both used. This happened to work because these wrappers map to the same internal SPL function. This was identified as a potential problem when a low-end memory constrained system began logging the following warnings. There was no deadlock here just repeated allocation failures resulting in increased latency. Possible memory allocation deadlock: size=65792 lflags=0x42d0 Pid: 20118, comm: kvm Tainted: P O 3.2.0-0.bpo.4-amd64 Call Trace: [<ffffffffa040b834>] ? spl_kmem_alloc_impl+0x115/0x127 [spl] [<ffffffffa040b84f>] ? spl_kmem_alloc_debug+0x9/0x36 [spl] [<ffffffffa05d8a0b>] ? zil_itx_create+0x2d/0x59 [zfs] [<ffffffffa05c71e6>] ? zfs_log_write+0x13a/0x2f0 [zfs] [<ffffffffa05d41bc>] ? zfs_write+0x85b/0x9bb [zfs] [<ffffffffa05e37ec>] ? zpl_aio_write+0xca/0x110 [zfs] [<ffffffff811088e5>] ? do_sync_readv_writev+0xa3/0xde [<ffffffff81108f41>] ? do_readv_writev+0xaf/0x125 [<ffffffff81109055>] ? sys_pwritev+0x55/0x9a [<ffffffff813721d2>] ? system_call_fastpath+0x16/0x1b Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Richard Yao <ryao@gentoo.org> Closes #3059 |
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Native ZFS for Linux!
ZFS is an advanced file system and volume manager which was originally developed for Solaris and is now maintained by the Illumos community.
ZFS on Linux, which is also known as ZoL, is currently feature complete. It includes fully functional and stable SPA, DMU, ZVOL, and ZPL layers.
Full documentation for installing ZoL on your favorite Linux distribution can be found at: http://zfsonlinux.org