[pve-devel] [PATCH installer v3 7/8] fix #4829: tui: setup: add new ZFS `arc_max` option

[Christoph Heiss <c.heiss@proxmox.com>]

Signed-off-by: Christoph Heiss <c.heiss@proxmox.com>
---
Changes v1 -> v2:
  * updated comment for ZfsBootdiskOptions::defaults_from() accordingly

Changes v2 -> v2:
  * documented the unit of the return value of default_zfs_arc_max()

 proxmox-tui-installer/src/options.rs        | 57 +++++++++++++++++++--
 proxmox-tui-installer/src/setup.rs          |  2 +
 proxmox-tui-installer/src/views/bootdisk.rs | 31 ++++++-----
 3 files changed, 71 insertions(+), 19 deletions(-)

diff --git a/proxmox-tui-installer/src/options.rs b/proxmox-tui-installer/src/options.rs
index 85b39b8..c9b036d 100644
--- a/proxmox-tui-installer/src/options.rs
+++ b/proxmox-tui-installer/src/options.rs
@@ -1,7 +1,9 @@
 use std::net::{IpAddr, Ipv4Addr};
 use std::{cmp, fmt};

-use crate::setup::{LocaleInfo, NetworkInfo, RuntimeInfo, SetupInfo};
+use crate::setup::{
+    LocaleInfo, NetworkInfo, ProductConfig, ProxmoxProduct, RuntimeInfo, SetupInfo,
+};
 use crate::utils::{CidrAddress, Fqdn};
 use crate::SummaryOption;

@@ -190,21 +192,23 @@ pub struct ZfsBootdiskOptions {
     pub compress: ZfsCompressOption,
     pub checksum: ZfsChecksumOption,
     pub copies: usize,
+    pub arc_max: usize,
     pub disk_size: f64,
     pub selected_disks: Vec<usize>,
 }

 impl ZfsBootdiskOptions {
-    /// This panics if the provided slice is empty.
-    pub fn defaults_from(disks: &[Disk]) -> Self {
-        let disk = &disks[0];
+    /// Panics if the disk list is empty.
+    pub fn defaults_from(runinfo: &RuntimeInfo, product_conf: &ProductConfig) -> Self {
+        let disk = &runinfo.disks[0];
         Self {
             ashift: 12,
             compress: ZfsCompressOption::default(),
             checksum: ZfsChecksumOption::default(),
             copies: 1,
+            arc_max: default_zfs_arc_max(product_conf.product, runinfo.total_memory),
             disk_size: disk.size,
-            selected_disks: (0..disks.len()).collect(),
+            selected_disks: (0..runinfo.disks.len()).collect(),
         }
     }
 }
@@ -444,6 +448,27 @@ impl InstallerOptions {
     }
 }

+/// Calculates the default upper limit for the ZFS ARC size.
+/// See also <https://bugzilla.proxmox.com/show_bug.cgi?id=4829> and
+/// https://openzfs.github.io/openzfs-docs/Performance%20and%20Tuning/Module%20Parameters.html#zfs-arc-max
+///
+/// # Arguments
+/// * `product` - The product to be installed
+/// * `total_memory` - Total memory installed in the system, in MiB
+///
+/// # Returns
+/// The default ZFS maximum ARC size in MiB for this system.
+fn default_zfs_arc_max(product: ProxmoxProduct, total_memory: usize) -> usize {
+    if product != ProxmoxProduct::PVE {
+        // Use ZFS default for non-PVE
+        0
+    } else {
+        ((total_memory as f64) / 10.)
+            .round()
+            .clamp(64., 16. * 1024.) as usize
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -470,6 +495,28 @@ mod tests {
         }
     }

+    #[test]
+    fn zfs_arc_limit() {
+        const TESTS: &[(usize, usize)] = &[
+            (16, 64), // at least 64 MiB
+            (1024, 102),
+            (4 * 1024, 410),
+            (8 * 1024, 819),
+            (150 * 1024, 15360),
+            (160 * 1024, 16384),
+            (1024 * 1024, 16384), // maximum of 16 GiB
+        ];
+
+        for (total_memory, expected) in TESTS {
+            assert_eq!(
+                default_zfs_arc_max(ProxmoxProduct::PVE, *total_memory),
+                *expected
+            );
+            assert_eq!(default_zfs_arc_max(ProxmoxProduct::PBS, *total_memory), 0);
+            assert_eq!(default_zfs_arc_max(ProxmoxProduct::PMG, *total_memory), 0);
+        }
+    }
+
     #[test]
     fn network_options_from_setup_network_info() {
         let setup = dummy_setup_info();
diff --git a/proxmox-tui-installer/src/setup.rs b/proxmox-tui-installer/src/setup.rs
index 5575759..e9fe70d 100644
--- a/proxmox-tui-installer/src/setup.rs
+++ b/proxmox-tui-installer/src/setup.rs
@@ -114,6 +114,7 @@ struct InstallZfsOption {
     #[serde(serialize_with = "serialize_as_display")]
     checksum: ZfsChecksumOption,
     copies: usize,
+    arc_max: usize,
 }

 impl From<ZfsBootdiskOptions> for InstallZfsOption {
@@ -123,6 +124,7 @@ impl From<ZfsBootdiskOptions> for InstallZfsOption {
             compress: opts.compress,
             checksum: opts.checksum,
             copies: opts.copies,
+            arc_max: opts.arc_max,
         }
     }
 }
diff --git a/proxmox-tui-installer/src/views/bootdisk.rs b/proxmox-tui-installer/src/views/bootdisk.rs
index 3addd6c..07ca5b7 100644
--- a/proxmox-tui-installer/src/views/bootdisk.rs
+++ b/proxmox-tui-installer/src/views/bootdisk.rs
@@ -16,7 +16,7 @@ use crate::{
         FsType, LvmBootdiskOptions, ZfsBootdiskOptions, ZfsRaidLevel, FS_TYPES,
         ZFS_CHECKSUM_OPTIONS, ZFS_COMPRESS_OPTIONS,
     },
-    setup::{BootType, ProductConfig},
+    setup::{BootType, ProductConfig, RuntimeInfo},
 };
 use crate::{setup::ProxmoxProduct, InstallerState};

@@ -123,10 +123,7 @@ impl AdvancedBootdiskOptionsView {
                     .position(|t| *t == options.fstype)
                     .unwrap_or_default(),
             )
-            .on_submit({
-                let disks = disks.to_owned();
-                move |siv, fstype| Self::fstype_on_submit(siv, &disks, fstype)
-            });
+            .on_submit(move |siv, fstype| Self::fstype_on_submit(siv, fstype));

         let mut view = LinearLayout::vertical()
             .child(DummyView.full_width())
@@ -148,8 +145,9 @@ impl AdvancedBootdiskOptionsView {
         Self { view }
     }

-    fn fstype_on_submit(siv: &mut Cursive, disks: &[Disk], fstype: &FsType) {
+    fn fstype_on_submit(siv: &mut Cursive, fstype: &FsType) {
         let state = siv.user_data::<InstallerState>().unwrap();
+        let runinfo = state.runtime_info.clone();
         let product_conf = state.setup_info.config.clone();

         siv.call_on_name("advanced-bootdisk-options-dialog", |view: &mut Dialog| {
@@ -159,13 +157,14 @@ impl AdvancedBootdiskOptionsView {
                 view.remove_child(3);
                 match fstype {
                     FsType::Ext4 | FsType::Xfs => view.add_child(
-                        LvmBootdiskOptionsView::new_with_defaults(&disks[0], &product_conf),
+                        LvmBootdiskOptionsView::new_with_defaults(&runinfo.disks[0], &product_conf),
                     ),
-                    FsType::Zfs(_) => {
-                        view.add_child(ZfsBootdiskOptionsView::new_with_defaults(disks))
-                    }
+                    FsType::Zfs(_) => view.add_child(ZfsBootdiskOptionsView::new_with_defaults(
+                        &runinfo,
+                        &product_conf,
+                    )),
                     FsType::Btrfs(_) => {
-                        view.add_child(BtrfsBootdiskOptionsView::new_with_defaults(disks))
+                        view.add_child(BtrfsBootdiskOptionsView::new_with_defaults(&runinfo.disks))
                     }
                 }
             }
@@ -179,7 +178,7 @@ impl AdvancedBootdiskOptionsView {
                         0,
                         SelectView::new()
                             .popup()
-                            .with_all(disks.iter().map(|d| (d.to_string(), d.clone()))),
+                            .with_all(runinfo.disks.iter().map(|d| (d.to_string(), d.clone()))),
                     );
                 }
                 other => view.replace_child(0, TextView::new(other.to_string())),
@@ -547,8 +546,11 @@ impl ZfsBootdiskOptionsView {
         Self { view }
     }

-    fn new_with_defaults(disks: &[Disk]) -> Self {
-        Self::new(disks, &ZfsBootdiskOptions::defaults_from(disks))
+    fn new_with_defaults(runinfo: &RuntimeInfo, product_conf: &ProductConfig) -> Self {
+        Self::new(
+            &runinfo.disks,
+            &ZfsBootdiskOptions::defaults_from(runinfo, product_conf),
+        )
     }

     fn get_values(&mut self) -> Option<(Vec<Disk>, ZfsBootdiskOptions)> {
@@ -568,6 +570,7 @@ impl ZfsBootdiskOptionsView {
                 compress,
                 checksum,
                 copies,
+                arc_max: 0, // use built-in ZFS default value
                 disk_size,
                 selected_disks,
             },
--
2.42.0