Date: Tue, 19 May 2015 03:34:55 +0000 From: bugzilla-noreply@freebsd.org To: freebsd-bugs@FreeBSD.org Subject: [Bug 200316] don't have compiler inline vdev_queue_max_async_writes so zfs write throttle tuning works Message-ID: <bug-200316-8@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D200316 Bug ID: 200316 Summary: don't have compiler inline vdev_queue_max_async_writes so zfs write throttle tuning works Product: Base System Version: 10.1-RELEASE Hardware: Any OS: Any Status: New Severity: Affects Only Me Priority: --- Component: kern Assignee: freebsd-bugs@FreeBSD.org Reporter: lacey.leanne@gmail.com Created attachment 156921 --> https://bugs.freebsd.org/bugzilla/attachment.cgi?id=3D156921&action= =3Dedit patch against 10.1-RELEASE to fix the issue. On unpatched systems vdev_queue_max_async_writes is inlined and hidden from dtrace.=20 This prevents the use of the q.d async write tuning script, as outlined here http://dtrace.org/blogs/ahl/2014/08/31/openzfs-tuning/ which makes it difficult to properly investigate and tune the ZFS write throttle on FreeBSD 10.1.=20 On unpatched systems the script reports: dtrace: failed to compile script ./q.d: line 6: probe description fbt::vdev_queue_max_async_writes:entry does not match any probes Once patched, the output looks like this: min .--------------------------------. max | count < 0 : =E2=96=88 : >=3D 30 | 174 min .--------------------------------. max | count < 0 : : >=3D 30 | 0 The attached patch adding __noinline fixes this.=20 The problem can be reproduced on unpatched systems with the attached q.d script. Thank you for your time and assistance in fixing this. --=20 You are receiving this mail because: You are the assignee for the bug.=
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