On 2011-05-13 18:07, Vasilis Liaskovitis wrote: > Hi, > > I am trying to use the splice ioengine to read/write from/to tmpfs (/dev/shm). > > Writing works fine e.g. with the following fio config: > [sw] > rw=write > size=1g > directory=/dev/shm > iodepth=32 > direct=0 > blocksize=512k > numjobs=1 > nrfiles=1 > ioengine=splice > loops=1 > group_reporting > create_on_open=1 > create_serialize=0 > > But reading the same file afterwards with the splice ioengine fails: > [sw] > rw=read > size=1g > directory=/dev/shm > iodepth=32 > direct=0 > blocksize=512k > numjobs=1 > nrfiles=1 > ioengine=splice > loops=1 > group_reporting > > root@server1:~/fio# ./fio /root/fior_splice.fio > sw: (g=0): rw=read, bs=512K-512K/512K-512K, ioengine=splice, iodepth=32 > fio 1.53 > Starting 1 process > fio: pid=17504, err=22/file:filesetup.c:502, > func=open(/dev/shm/sw.1.0), error=Invalid argument > Run status group 0 (all jobs): > > Is something misconfigured in the fio read config? > The --debug=all output is: It's a bug in fio. We used to set O_DIRECT just in case vmsplice could map into user address space, which is why it fails (/dev/shm/ does not do O_DIRECT). There's actually a way to set this correctly now, the below patch will work for you. I'll commit it now. diff --git a/engines/splice.c b/engines/splice.c index be16cbb..aa00234 100644 --- a/engines/splice.c +++ b/engines/splice.c @@ -284,7 +284,7 @@ static int fio_spliceio_init(struct thread_data *td) * buffers. Just set ->odirect to force that. */ if (td_read(td)) - td->o.odirect = 1; + td->o.mem_align = 1; td->io_ops->data = sd; return 0; -- Jens Axboe -- To unsubscribe from this list: send the line "unsubscribe fio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
