linux

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Stefano Stabellini 36f9967531 9p/xen: increase XEN_9PFS_RING_ORDER

Increase XEN_9PFS_RING_ORDER to 9 for performance reason. Order 9 is the
max allowed by the protocol.

We can't assume that all backends will support order 9. The xenstore
property max-ring-page-order specifies the max order supported by the
backend. We'll use max-ring-page-order for the size of the ring.

This means that the size of the ring is not static
(XEN_FLEX_RING_SIZE(9)) anymore. Change XEN_9PFS_RING_SIZE to take an
argument and base the calculation on the order chosen at setup time.

Finally, modify p9_xen_trans.maxsize to be divided by 4 compared to the
original value. We need to divide it by 2 because we have two rings
coming off the same order allocation: the in and out rings. This was a
mistake in the original code. Also divide it further by 2 because we
don't want a single request/reply to fill up the entire ring. There can
be multiple requests/replies outstanding at any given time and if we use
the full ring with one, we risk forcing the backend to wait for the
client to read back more replies before continuing, which is not
performant.

Link: http://lkml.kernel.org/r/20200521193242.15953-1-sstabellini@kernel.org
Signed-off-by: Stefano Stabellini <stefano.stabellini@xilinx.com>
Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr>

2020-06-02 08:00:39 +02:00

client.c

9pnet: allow making incomplete read requests

2020-03-27 09:29:56 +00:00

error.c

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 188

2019-05-30 11:29:21 -07:00

Kconfig

treewide: Add SPDX license identifier - Makefile/Kconfig

2019-05-21 10:50:46 +02:00

Makefile

9p: Remove p9_idpool