From: "Marek Marczykowski-Górecki" <email@example.com> To: firstname.lastname@example.org Cc: "Marek Marczykowski-Górecki" <email@example.com>, "Ian Jackson" <firstname.lastname@example.org>, "Wei Liu" <email@example.com>, "Anthony PERARD" <firstname.lastname@example.org> Subject: [RFC PATCH 0/2] libxl: support common cases without block script Date: Tue, 27 Apr 2021 02:22:30 +0200 [thread overview] Message-ID: <email@example.com> (raw) This series in an attempt to speed up the domain start by removing slow block script from the picture. The current RFC covers the simplest possible case only - target being a block device directly. This case does not require locking at all. Further version will cover also setting up a loop device. This, compared to the default block script, saves about 0.5s of domain start time, per disk. Similar speedup can be achieved with a trivial lock-less script too. But for file-based disks, it won't be that simple with a script - setting up a loop device lock-less is tricky and ability to keep an FD open and call different ioctls on it greatly helps. Furthermore reusing the same loop device for the same file can be done significantly better with a cache (which can be stored in the libxl hosting process - like xl devd, or libvirt). This surely isn't the only option to improve disk setup time, but is a very atractive one. Few questions: 1. Is it acceptable approach at all? 2. Is empty 'script' parameter value going to fly? Unfortunately, NULL is already taken as "use default". Marek Marczykowski-Górecki (2): libxl: rename 'error' label to 'out' as it is used for success too libxl: allow to skip block script completely docs/man/xl-disk-configuration.5.pod.in | 4 ++- tools/libs/light/libxl_disk.c | 7 ++- tools/libs/light/libxl_linux.c | 68 ++++++++++++++++++++++++-- 3 files changed, 74 insertions(+), 5 deletions(-) base-commit: bea65a212c0581520203b6ad0d07615693f42f73 -- git-series 0.9.1
next reply other threads:[~2021-04-27 0:24 UTC|newest] Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-04-27 0:22 Marek Marczykowski-Górecki [this message] 2021-04-27 0:22 ` [RFC PATCH 1/2] libxl: rename 'error' label to 'out' as it is used for success too Marek Marczykowski-Górecki 2021-04-27 0:22 ` [RFC PATCH 2/2] libxl: allow to skip block script completely Marek Marczykowski-Górecki 2021-04-28 6:48 ` [RFC PATCH 0/2] libxl: support common cases without block script Demi Marie Obenour 2021-04-28 12:26 ` Jason Andryuk
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