Messages in this thread | | | From | Miklos Szeredi <> | Subject | Re: [PATCH -v2 4/6] fuse: add a sysfs parameter to control the maximum request size | Date | Wed, 08 Aug 2012 16:43:54 +0200 |
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Mitsuo Hayasaka <mitsuo.hayasaka.hu@hitachi.com> writes:
> Add a max_pages_per_req sysfs paramater to limit the maximum > read/write request size. It can be changed to arbitrary number > between 32 and the nr_pages equivalent to pipe_max_size, and the > 32 pages are set by default. > > The sysfs parameter control is required, as follows. > > * The libfuse should change the current MIN_BUFSIZE limitation > according to the current maximum request size in FUSE. If not, > the libfuse must always set MIN_BUFSIZE to the maximum request > limit (= [nr_pages (equivalent to pipe_max_size) * 4KB + 0x1000]), > which leads to waste of memory.
I don't see the purpose of this sysfs parameter. Userspace can calculate the needed buffer size from the max_read/max_write parameters, can't it?
> > * It is easy to find and set the paramter to the optimized value > in order to improve the read/write throughput, since the > maximum request limit does not always provides the highest > throughput.
So basically this is a global max_read/max_write limit? For that a better solution would be to add it to /etc/fuse.conf.
But I have doubts about whether this is useful.
Thanks, Miklos
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