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| author | Stefan Metzmacher <metze@samba.org> | 2022-08-16 14:17:50 +0200 |
|---|---|---|
| committer | Stefan Metzmacher <metze@samba.org> | 2022-08-16 19:37:17 +0000 |
| commit | 8b6cea8105c8e8f3f5279b0ee62d36fa467e316d (patch) | |
| tree | 7ec19581fcc90c972aad38988f98b6c6a8c9650c /WHATSNEW.txt | |
| parent | c027512a6128f40ba9f533b624535ccfdba1260b (diff) | |
| download | samba-8b6cea8105c8e8f3f5279b0ee62d36fa467e316d.tar.gz | |
WHATSNEW: SMB Server performance improvements
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Ralph Boehme <slow@samba.org>
Autobuild-User(v4-17-test): Stefan Metzmacher <metze@samba.org>
Autobuild-Date(v4-17-test): Tue Aug 16 19:37:17 UTC 2022 on sn-devel-184
Diffstat (limited to 'WHATSNEW.txt')
| -rw-r--r-- | WHATSNEW.txt | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/WHATSNEW.txt b/WHATSNEW.txt index 006220f0d4c..9ef0bcc68d7 100644 --- a/WHATSNEW.txt +++ b/WHATSNEW.txt @@ -16,6 +16,27 @@ UPGRADING NEW FEATURES/CHANGES ==================== +SMB Server performance improvements +----------------------------------- + +The security improvements in recent releases +(4.13, 4.14, 4.15, 4.16), mainly as protection against symlink races, +caused performance regressions for meta data heavy workloads. + +With 4.17 the situation improved a lot again: + +- Pathnames given by a client are devided into dirname and basename. + The amount of syscalls to validate dirnames is reduced to 2 syscalls + (openat, close) per component. On modern Linux kernels (>= 5.6) smbd + makes use of the openat2() syscall with RESOLVE_NO_SYMLINKS, + in order to just use 2 syscalls (openat2, close) for the whole dirname. + +- Contended path based operations used to generate a lot of unsolicited + wakeup events causing thundering herd problems, which lead to masive + latencies for some clients. These events are now avoided in order + to provide stable latencies and much higher throughput of open/close + operations. + Configure without the SMB1 Server --------------------------------- |