From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Tue, 16 Feb 2021 17:55:26 +0000 From: "Dr. David Alan Gilbert" Message-ID: References: <20210210182744.27324-1-vgoyal@redhat.com> <20210210182744.27324-2-vgoyal@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210210182744.27324-2-vgoyal@redhat.com> Subject: Re: [Virtio-fs] [PATCH 1/1] virtiofsd: Do not use a thread pool by default List-Id: Development discussions about virtio-fs List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Vivek Goyal Cc: virtio-fs@redhat.com, qemu-devel@nongnu.org * Vivek Goyal (vgoyal@redhat.com) wrote: > Currently we created a thread pool (With 64 max threads per pool) for > each virtqueue. We hoped that this will provide us with better scalability > and performance. > > But in practice, we are getting better numbers in most of the cases > when we don't create a thread pool at all and a single thread per > virtqueue receives the request and processes it. > > Hence, I am proposing that we switch to no thread pool by default > (equivalent of --thread-pool-size=0). This will provide out of > box better performance to most of the users. In fact other users > have confirmed that not using a thread pool gives them better > numbers. So why not use this as default. It can be changed when > somebody can fix the issues with thread pool performance. > > Signed-off-by: Vivek Goyal OK, lets try it - I still worry it really means we're missing something silly about them, you'd really think eventually the threads should help. Reviewed-by: Dr. David Alan Gilbert > --- > tools/virtiofsd/fuse_lowlevel.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/tools/virtiofsd/fuse_lowlevel.c b/tools/virtiofsd/fuse_lowlevel.c > index e94b71110b..fbdf62ee9b 100644 > --- a/tools/virtiofsd/fuse_lowlevel.c > +++ b/tools/virtiofsd/fuse_lowlevel.c > @@ -18,7 +18,7 @@ > > #include > > -#define THREAD_POOL_SIZE 64 > +#define THREAD_POOL_SIZE 0 > > #define OFFSET_MAX 0x7fffffffffffffffLL > > -- > 2.25.4 -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK