[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: 2.6.0-test9-mm3 - AIO test results
Suparna,
Good news and bad news. Your patch does fix the non-power of two i/o
size problems where AIO previously did not complete:
$ ./aiodio_sparse -s 1751k -r 18k -w 11k
$ aiodio_sparse -i 9 -dd -s 180k -r 18k -w 18k
io_submit() return 9
aiodio_sparse: 9 i/o in flight
aiodio_sparse: offset 165888 filesize 184320 inflight 9
aiodio_sparse: io_getevent() returned 1
aiodio_sparse: io_getevent() res 18432 res2 0
io_submit() return 1
AIO DIO write done unlinking file
dio_sparse done writing, kill children
aiodio_sparse 0 children had errors
But when testing using aiocp using O_DIRECT to copy a file to
an already allocated file, the aiocp process hangs. I used i/o
size of 4k and that compeleted. Using i/o size of 1k and 2k,
the aiocp process hung during io_sumbit() and are unkillable.
Here are the stack traces:
# ps -fu daniel | grep aiocp
daniel 1920 1 0 16:45 ? 00:00:07 aiocp -b 1k -n 1 -f DIRECT glibc-2.3.2.tar ff2
daniel 2083 2037 0 17:00 pts/2 00:00:03 aiocp -dd -b 1k -n 8 -f DIRECT glibc-2.3.2.tar ff2
aiocp D 00000001 1920 1 1902 (NOTLB)
e70abd04 00200086 c18dbc80 00000001 00000003 c02897fc 00000060 00200246
f7cdb8b4 c16522f0 c18dbc80 0000309c 640a05eb 0000008b e6d9e660
c0289a16
f7cdb8b4 e87e95cc c18dbc80 00000000 00000001 e70abd10 c0123712
e70aa000
Call Trace:
[<c02897fc>] generic_unplug_device+0x50/0xbd
[<c0289a16>] blk_run_queues+0xa9/0x15c
[<c0123712>] io_schedule+0x26/0x30
[<c0192242>] direct_io_worker+0x376/0x5ab
[<c014840f>] generic_file_direct_IO+0x70/0x89
[<c019264a>] __blockdev_direct_IO+0x1d3/0x2d5
[<c01ac73e>] ext3_direct_io_get_blocks+0x0/0xbf
[<c01ad72d>] ext3_direct_IO+0xc0/0x1e1
[<c01ac73e>] ext3_direct_io_get_blocks+0x0/0xbf
[<c014840f>] generic_file_direct_IO+0x70/0x89
[<c0145e11>] __generic_file_aio_read+0xfb/0x1ff
[<c0121b70>] schedule+0x3ac/0x7ef
[<c0145f48>] generic_file_aio_read+0x33/0x37
[<c0194ad3>] aio_pread+0x34/0x5f
[<c0193bec>] aio_run_iocb+0xa6/0x1ed
[<c019316f>] __aio_get_req+0x27/0x158
[<c0194a9f>] aio_pread+0x0/0x5f
[<c0194f62>] io_submit_one+0x1ea/0x2b7
[<c0195110>] sys_io_submit+0xe1/0x194
[<c03c29a7>] syscall_call+0x7/0xb
[<c03c007b>] rpc_depopulate+0x1aa/0x24b
aiocp D 366EDC94 2083 2037 (NOTLB)
e758bd04 00200082 f71ba000 366edc94 00000161 c02897fc 00000060 366edc94
00000161 f71ba000 c18d3c80 000069a9 366f5a0e 00000161 e8d4acc0 c0289a16
f7cdb8b4 e960465c c18d3c80 00000000 00000001 e758bd10 c0123712 e758a000
Call Trace:
[<c02897fc>] generic_unplug_device+0x50/0xbd
[<c0289a16>] blk_run_queues+0xa9/0x15c
[<c0123712>] io_schedule+0x26/0x30
[<c0192242>] direct_io_worker+0x376/0x5ab
[<c019264a>] __blockdev_direct_IO+0x1d3/0x2d5
[<c01ac73e>] ext3_direct_io_get_blocks+0x0/0xbf
[<c01ad72d>] ext3_direct_IO+0xc0/0x1e1
[<c01ac73e>] ext3_direct_io_get_blocks+0x0/0xbf
[<c014840f>] generic_file_direct_IO+0x70/0x89
[<c0145e11>] __generic_file_aio_read+0xfb/0x1ff
[<c0259d3e>] write_chan+0x165/0x21e
[<c0145f48>] generic_file_aio_read+0x33/0x37
[<c0194ad3>] aio_pread+0x34/0x5f
[<c0193bec>] aio_run_iocb+0xa6/0x1ed
[<c019316f>] __aio_get_req+0x27/0x158
[<c0194a9f>] aio_pread+0x0/0x5f
[<c02532ab>] tty_write+0x1e8/0x3b2
[<c0194f62>] io_submit_one+0x1ea/0x2b7
[<c0195110>] sys_io_submit+0xe1/0x194
[<c03c29a7>] syscall_call+0x7/0xb
[<c03c007b>] rpc_depopulate+0x1aa/0x24b
Daniel
On Sun, 2003-11-16 at 21:25, Suparna Bhattacharya wrote:
> On Thu, Nov 13, 2003 at 02:03:58PM -0800, Daniel McNeil wrote:
> > Andrew,
> >
> > I'm testing test9-mm3 on a 2-proc Xeon with a ext3 file system.
> > I tested using the test programs aiocp and aiodio_sparse.
> > (see http://developer.osdl.org/daniel/AIO/)
> >
> > Using aiocp with i/o sizes from 1k to 512k to copy files worked
> > without any errors or kernel debug messages.
> >
> > With 64k i/o, the aiodio_sparse program complete without any errors.
> > There are no kernel error messages, so that is good.
> >
> > There are still problems with non power of 2 i/o sizes using AIO and
> > O_DIRECT. It hangs with aio's that do not seem to complete. The test
> > does exit when hitting ^c and there are no kernel messages. Test output
> > below:
>
> Could you check if the following patch fixes the problem for you ?
>
> Regards
> Suparna
>
> --------------------------------------------------------------
>
> With this patch, when the DIO code falls back to buffered i/o after
> having submitted part of the i/o, then buffered i/o is issued only
> for the remaining part of the request (i.e. the part not already
> covered by DIO).
>
> diff -ur pure-mm3/fs/direct-io.c linux-2.6.0-test9-mm3/fs/direct-io.c
> --- pure-mm3/fs/direct-io.c 2003-11-14 09:09:06.000000000 +0530
> +++ linux-2.6.0-test9-mm3/fs/direct-io.c 2003-11-17 09:00:47.000000000 +0530
> @@ -74,6 +74,7 @@
> been performed at the start of a
> write */
> int pages_in_io; /* approximate total IO pages */
> + size_t size; /* total request size (doesn't change)*/
> sector_t block_in_file; /* Current offset into the underlying
> file in dio_block units. */
> unsigned blocks_available; /* At block_in_file. changes */
> @@ -226,7 +227,7 @@
> dio_complete(dio, dio->block_in_file << dio->blkbits,
> dio->result);
> /* Complete AIO later if falling back to buffered i/o */
> - if (dio->result != -ENOTBLK) {
> + if (dio->result >= dio->size || dio->rw == READ) {
> aio_complete(dio->iocb, dio->result, 0);
> kfree(dio);
> } else {
> @@ -889,6 +890,7 @@
> dio->blkbits = blkbits;
> dio->blkfactor = inode->i_blkbits - blkbits;
> dio->start_zero_done = 0;
> + dio->size = 0;
> dio->block_in_file = offset >> blkbits;
> dio->blocks_available = 0;
> dio->cur_page = NULL;
> @@ -925,7 +927,7 @@
>
> for (seg = 0; seg < nr_segs; seg++) {
> user_addr = (unsigned long)iov[seg].iov_base;
> - bytes = iov[seg].iov_len;
> + dio->size += bytes = iov[seg].iov_len;
>
> /* Index into the first page of the first block */
> dio->first_block_in_page = (user_addr & ~PAGE_MASK) >> blkbits;
> @@ -956,6 +958,13 @@
> }
> } /* end iovec loop */
>
> + if (ret == -ENOTBLK && rw == WRITE) {
> + /*
> + * The remaining part of the request will be
> + * be handled by buffered I/O when we return
> + */
> + ret = 0;
> + }
> /*
> * There may be some unwritten disk at the end of a part-written
> * fs-block-sized block. Go zero that now.
> @@ -986,19 +995,13 @@
> */
> if (dio->is_async) {
> if (ret == 0)
> - ret = dio->result; /* Bytes written */
> - if (ret == -ENOTBLK) {
> - /*
> - * The request will be reissued via buffered I/O
> - * when we return; Any I/O already issued
> - * effectively becomes redundant.
> - */
> - dio->result = ret;
> + ret = dio->result;
> + if (ret > 0 && dio->result < dio->size && rw == WRITE) {
> dio->waiter = current;
> }
> finished_one_bio(dio); /* This can free the dio */
> blk_run_queues();
> - if (ret == -ENOTBLK) {
> + if (dio->waiter) {
> /*
> * Wait for already issued I/O to drain out and
> * release its references to user-space pages
> @@ -1032,7 +1035,8 @@
> }
> dio_complete(dio, offset, ret);
> /* We could have also come here on an AIO file extend */
> - if (!is_sync_kiocb(iocb) && (ret != -ENOTBLK))
> + if (!is_sync_kiocb(iocb) && !(rw == WRITE && ret >= 0 &&
> + dio->result < dio->size))
> aio_complete(iocb, ret, 0);
> kfree(dio);
> }
> diff -ur pure-mm3/mm/filemap.c linux-2.6.0-test9-mm3/mm/filemap.c
> --- pure-mm3/mm/filemap.c 2003-11-14 09:15:08.000000000 +0530
> +++ linux-2.6.0-test9-mm3/mm/filemap.c 2003-11-15 11:11:16.000000000 +0530
> @@ -1895,14 +1895,16 @@
> */
> if (written >= 0 && file->f_flags & O_SYNC)
> status = generic_osync_inode(inode, mapping, OSYNC_METADATA);
> - if (written >= 0 && !is_sync_kiocb(iocb))
> + if (written >= count && !is_sync_kiocb(iocb))
> written = -EIOCBQUEUED;
> - if (written != -ENOTBLK)
> + if (written < 0 || written >= count)
> goto out_status;
> /*
> * direct-io write to a hole: fall through to buffered I/O
> + * for completing the rest of the request.
> */
> - written = 0;
> + pos += written;
> + count -= written;
> }
>
> buf = iov->iov_base;
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"aart@kvack.org"> aart@kvack.org </a>