From: Max Reitz <mreitz@redhat.com>
To: Vivek Goyal <vgoyal@redhat.com>
Cc: virtio-fs@redhat.com, qemu-devel@nongnu.org,
Stefan Hajnoczi <stefanha@redhat.com>,
"Dr . David Alan Gilbert" <dgilbert@redhat.com>
Subject: Re: [PATCH v2 0/9] virtiofsd: Allow using file handles instead of O_PATH FDs
Date: Wed, 16 Jun 2021 15:41:36 +0200 [thread overview]
Message-ID: <ddc46d6a-70c0-5d5e-c704-514be7a3c014@redhat.com> (raw)
In-Reply-To: <20210611191925.GA767764@redhat.com>
On 11.06.21 21:19, Vivek Goyal wrote:
> On Wed, Jun 09, 2021 at 05:55:42PM +0200, Max Reitz wrote:
>> Hi,
>>
>> v1 cover letter for an overview:
>> https://listman.redhat.com/archives/virtio-fs/2021-June/msg00033.html
> Hi Max,
>
> What's the impact of these patches on performance? Just trying to
> get some idea what to expect. Performance remains more or less
> same or we expect a hit.
I definitely expect a hit if you just benchmark the right way. Having to
open FDs all the time (for metadata operations) will have an impact
(when you do lookups all the time, or open files and close them
immediately). How much of an impact, that’s completely up to the
filesystem’s open_by_handle_at() implementation, I presume.
I don’t expect it to be significant for real-world use cases, though.
When really doing I/O, there should be absolutely no difference, because
then we’re operating with these FUSE handles that have actual (non-path)
FDs attached to them.
Max
WARNING: multiple messages have this Message-ID (diff)
From: Max Reitz <mreitz@redhat.com>
To: Vivek Goyal <vgoyal@redhat.com>
Cc: virtio-fs@redhat.com, qemu-devel@nongnu.org
Subject: Re: [Virtio-fs] [PATCH v2 0/9] virtiofsd: Allow using file handles instead of O_PATH FDs
Date: Wed, 16 Jun 2021 15:41:36 +0200 [thread overview]
Message-ID: <ddc46d6a-70c0-5d5e-c704-514be7a3c014@redhat.com> (raw)
In-Reply-To: <20210611191925.GA767764@redhat.com>
On 11.06.21 21:19, Vivek Goyal wrote:
> On Wed, Jun 09, 2021 at 05:55:42PM +0200, Max Reitz wrote:
>> Hi,
>>
>> v1 cover letter for an overview:
>> https://listman.redhat.com/archives/virtio-fs/2021-June/msg00033.html
> Hi Max,
>
> What's the impact of these patches on performance? Just trying to
> get some idea what to expect. Performance remains more or less
> same or we expect a hit.
I definitely expect a hit if you just benchmark the right way. Having to
open FDs all the time (for metadata operations) will have an impact
(when you do lookups all the time, or open files and close them
immediately). How much of an impact, that’s completely up to the
filesystem’s open_by_handle_at() implementation, I presume.
I don’t expect it to be significant for real-world use cases, though.
When really doing I/O, there should be absolutely no difference, because
then we’re operating with these FUSE handles that have actual (non-path)
FDs attached to them.
Max
next prev parent reply other threads:[~2021-06-16 13:42 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-09 15:55 [PATCH v2 0/9] virtiofsd: Allow using file handles instead of O_PATH FDs Max Reitz
2021-06-09 15:55 ` [Virtio-fs] " Max Reitz
2021-06-09 15:55 ` [PATCH v2 1/9] virtiofsd: Add TempFd structure Max Reitz
2021-06-09 15:55 ` [Virtio-fs] " Max Reitz
2021-06-09 15:55 ` [PATCH v2 2/9] virtiofsd: Use lo_inode_open() instead of openat() Max Reitz
2021-06-09 15:55 ` [Virtio-fs] " Max Reitz
2021-06-09 15:55 ` [PATCH v2 3/9] virtiofsd: Add lo_inode_fd() helper Max Reitz
2021-06-09 15:55 ` [Virtio-fs] " Max Reitz
2021-06-09 15:55 ` [PATCH v2 4/9] virtiofsd: Let lo_fd() return a TempFd Max Reitz
2021-06-09 15:55 ` [Virtio-fs] " Max Reitz
2021-06-09 15:55 ` [PATCH v2 5/9] virtiofsd: Let lo_inode_open() " Max Reitz
2021-06-09 15:55 ` [Virtio-fs] " Max Reitz
2021-06-09 15:55 ` [PATCH v2 6/9] virtiofsd: Add lo_inode.fhandle Max Reitz
2021-06-09 15:55 ` [Virtio-fs] " Max Reitz
2021-06-09 15:55 ` [PATCH v2 7/9] virtiofsd: Add inodes_by_handle hash table Max Reitz
2021-06-09 15:55 ` [Virtio-fs] " Max Reitz
2021-06-11 20:04 ` Vivek Goyal
2021-06-16 13:38 ` Max Reitz
2021-06-17 21:21 ` Vivek Goyal
2021-06-18 8:28 ` Max Reitz
2021-06-18 18:29 ` Vivek Goyal
2021-06-21 9:02 ` Max Reitz
2021-06-21 15:51 ` Vivek Goyal
2021-06-21 17:07 ` Max Reitz
2021-06-21 21:27 ` Vivek Goyal
2021-07-13 15:07 ` Max Reitz
2021-07-20 14:50 ` Vivek Goyal
2021-07-21 8:29 ` Max Reitz
2021-06-18 8:30 ` Max Reitz
2021-06-18 8:30 ` [Virtio-fs] " Max Reitz
2021-06-09 15:55 ` [PATCH v2 8/9] virtiofsd: Optionally fill lo_inode.fhandle Max Reitz
2021-06-09 15:55 ` [Virtio-fs] " Max Reitz
2021-06-09 15:55 ` [PATCH v2 9/9] virtiofsd: Add lazy lo_do_find() Max Reitz
2021-06-09 15:55 ` [Virtio-fs] " Max Reitz
2021-06-11 19:19 ` [PATCH v2 0/9] virtiofsd: Allow using file handles instead of O_PATH FDs Vivek Goyal
2021-06-11 19:19 ` [Virtio-fs] " Vivek Goyal
2021-06-16 13:41 ` Max Reitz [this message]
2021-06-16 13:41 ` Max Reitz
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