Messages in this thread | | | Date | Thu, 11 Apr 2013 15:22:07 +0400 | From | "Maxim V. Patlasov" <> | Subject | Re: [fuse-devel] [PATCH v2 0/6] fuse: process direct IO asynchronously |
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Hi Miklos,
Any feedback would be highly appreciated.
Thanks, Maxim
12/14/2012 07:20 PM, Maxim V. Patlasov пишет: > Hi, > > Existing fuse implementation always processes direct IO synchronously: it > submits next request to userspace fuse only when previous is completed. This > is suboptimal because: 1) libaio DIO works in blocking way; 2) userspace fuse > can't achieve parallelism processing several requests simultaneously (e.g. > in case of distributed network storage); 3) userspace fuse can't merge > requests before passing it to actual storage. > > The idea of the patch-set is to submit fuse requests in non-blocking way > (where it's possible) and either return -EIOCBQUEUED or wait for their > completion synchronously. The patch-set to be applied on top of for-next of > Miklos' git repo. > > To estimate performance improvement I used slightly modified fusexmp over > tmpfs (clearing O_DIRECT bit from fi->flags in xmp_open). For synchronous > operations I used 'dd' like this: > > dd of=/dev/null if=/fuse/mnt/file bs=2M count=256 iflag=direct > dd if=/dev/zero of=/fuse/mnt/file bs=2M count=256 oflag=direct conv=notrunc > > For AIO I used 'aio-stress' like this: > > aio-stress -s 512 -a 4 -b 1 -c 1 -O -o 1 /fuse/mnt/file > aio-stress -s 512 -a 4 -b 1 -c 1 -O -o 0 /fuse/mnt/file > > The throughput on some commodity (rather feeble) server was (in MB/sec): > > original / patched > > dd reads: ~322 / ~382 > dd writes: ~277 / ~288 > > aio reads: ~380 / ~459 > aio writes: ~319 / ~353 > > Changed in v2 - cleanups suggested by Brian: > - Updated fuse_io_priv with an async field and file pointer to preserve > the current style of interface (i.e., use this instead of iocb). > - Trigger the type of request submission based on the async field. > - Pulled up the fuse_write_update_size() call out of __fuse_direct_write() > to make the separate paths more consistent. > > Thanks, > Maxim > > --- > > Maxim V. Patlasov (6): > fuse: move fuse_release_user_pages() up > fuse: add support of async IO > fuse: make fuse_direct_io() aware about AIO > fuse: enable asynchronous processing direct IO > fuse: truncate file if async dio failed > fuse: optimize short direct reads > > > fs/fuse/cuse.c | 6 + > fs/fuse/file.c | 290 +++++++++++++++++++++++++++++++++++++++++++++++------- > fs/fuse/fuse_i.h | 19 +++- > 3 files changed, 276 insertions(+), 39 deletions(-) >
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