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authorAlexander Motin <[email protected]>2023-06-09 15:40:55 -0400
committerGitHub <[email protected]>2023-06-09 12:40:55 -0700
commit70ea484e3ec56c529c6c5027ffc43840100ce224 (patch)
treed006081f0701728fe2b3a743cbd47e54e25fbac2 /man/man8
parent6db4ed51d6c2cd8ec6a3ad318118f7a0d6b6dfe8 (diff)
Finally drop long disabled vdev cache.
It was a vdev level read cache, designed to aggregate many small reads by speculatively issuing bigger reads instead and caching the result. But since it has almost no idea about what is going on with exception of ZIO_FLAG_DONT_CACHE flag set by higher layers, it was found to make more harm than good, for which reason it was disabled for the past 12 years. These days we have much better instruments to enlarge the I/Os, such as speculative and prescient prefetches, I/O scheduler, I/O aggregation etc. Besides just the dead code removal this removes one extra mutex lock/unlock per write inside vdev_cache_write(), not otherwise disabled and trying to do some work. Reviewed-by: Brian Behlendorf <[email protected]> Signed-off-by: Alexander Motin <[email protected]> Sponsored by: iXsystems, Inc. Closes #14953
Diffstat (limited to 'man/man8')
-rw-r--r--man/man8/zpool-events.81
1 files changed, 0 insertions, 1 deletions
diff --git a/man/man8/zpool-events.8 b/man/man8/zpool-events.8
index 0ba93e416..341f902fe 100644
--- a/man/man8/zpool-events.8
+++ b/man/man8/zpool-events.8
@@ -456,7 +456,6 @@ ZIO_FLAG_CANFAIL:0x00000080
ZIO_FLAG_SPECULATIVE:0x00000100
ZIO_FLAG_CONFIG_WRITER:0x00000200
ZIO_FLAG_DONT_RETRY:0x00000400
-ZIO_FLAG_DONT_CACHE:0x00000800
ZIO_FLAG_NODATA:0x00001000
ZIO_FLAG_INDUCE_DAMAGE:0x00002000