zfs: add zio_buf_alloc_nowait and use it in vdev_queue_aggregate
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Authored by avg on Mar 14 2017, 1:37 PM.

Details

Summary

This way we can avoid blocking the whole queue in the low memory
situations. It's better to sacrifice some I/O performance by not doing
the aggregation than to add an indefinite wait for more memory.

Test Plan

Different workloads on a ZFS-only system (with non-ZFS swap).

Diff Detail

Repository
rS FreeBSD src repository
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avg created this revision.Mar 14 2017, 1:37 PM
smh accepted this revision.Mar 14 2017, 1:46 PM

LGTM

This revision is now accepted and ready to land.Mar 14 2017, 1:46 PM
This revision was automatically updated to reflect the committed changes.