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authorAlexander Motin <mav@FreeBSD.org>2021-04-06 21:27:16 +0000
committerAlexander Motin <mav@FreeBSD.org>2021-04-06 21:27:16 +0000
commitac503c194cd8e9dbef5c120e87f9521e1a89003a (patch)
treeb8c297e29f4ec486435562f1deb706d1b9309b0a /sys/cam/ctl/ctl_backend.h
parent13b3862ee874db0b5efae484934de9b20da864e4 (diff)
downloadsrc-ac503c194cd8e9dbef5c120e87f9521e1a89003a.tar.gz
src-ac503c194cd8e9dbef5c120e87f9521e1a89003a.zip
Introduce "soft" serseq variant.
With new ZFS prefetcher improvements it is no longer needed to fully serialize reads to reach decent prediction hit rate. Softer variant only creates small time window to reduce races instead of completely blocking following reads while previous is running. It much less hurts the performance in case of prediction miss. MFC after: 1 month
Diffstat (limited to 'sys/cam/ctl/ctl_backend.h')
-rw-r--r--sys/cam/ctl/ctl_backend.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/sys/cam/ctl/ctl_backend.h b/sys/cam/ctl/ctl_backend.h
index 05e65abe41f8..fe4e7f5df1d0 100644
--- a/sys/cam/ctl/ctl_backend.h
+++ b/sys/cam/ctl/ctl_backend.h
@@ -47,6 +47,7 @@
typedef enum {
CTL_LUN_SERSEQ_OFF,
+ CTL_LUN_SERSEQ_SOFT,
CTL_LUN_SERSEQ_READ,
CTL_LUN_SERSEQ_ON
} ctl_lun_serseq;