Question(s) about smbd in respect to preadv2

Volker Lendecke Volker.Lendecke at SerNet.DE
Sun Jan 25 00:12:01 MST 2015

On Sat, Jan 24, 2015 at 03:46:18PM -0500, Milosz Tanski wrote:
> The results were that sync was fastest (no surprise there).
> Pthreadpool + preadv2 was about 8% slower then sync. Plain old
> pthreadpool 26% slower. So not a bad win there. Additionally, it looks
> like the vfs_pread_send and vfs_pread_recv have a bit more overhead
> over plain old vfs_pread in the code path so it's possible to get that
> 8% even closer to the sync case.

Indeed. The change I proposed was really the minimum number
of code lines to be achieved as quickly as possible. If
preadv2 succeeds we don't have to set up the tevent_req
stuff at all, which might add the overhead (basically malloc
cost). But this would happen at a different layer with a
little more code effort (possibly a VFS change).


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