Date: Fri, 12 Apr 2013 10:03:33 +0300 From: Andriy Gapon <avg@FreeBSD.org> To: Adam Nowacki <nowakpl@platinum.linux.pl> Cc: freebsd-fs@FreeBSD.org Subject: Re: ZFS slow reads for unallocated blocks Message-ID: <5167B1C5.8020402@FreeBSD.org> In-Reply-To: <5166EA43.7050700@platinum.linux.pl> References: <5166EA43.7050700@platinum.linux.pl>
next in thread | previous in thread | raw e-mail | index | archive | help
ENOTIME to really investigate, but here is a basic profile result for those
interested:
kernel`bzero+0xa
kernel`dmu_buf_hold_array_by_dnode+0x1cf
kernel`dmu_read_uio+0x66
kernel`zfs_freebsd_read+0x3c0
kernel`VOP_READ_APV+0x92
kernel`vn_read+0x1a3
kernel`vn_io_fault+0x23a
kernel`dofileread+0x7b
kernel`sys_read+0x9e
kernel`amd64_syscall+0x238
kernel`0xffffffff80747e4b
That's where > 99% of time is spent.
--
Andriy Gapon
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?5167B1C5.8020402>