From: Bohdan Khomutskyi <bkhomuts(a)redhat.com>
I discovered that several kernel configuration options related to SquashFS decompression
are set sub-optimally in Fedora. But the optimal configuration is used in RHEL 8.
If we set those options to match RHEL, a performance improvement could be achieved while
reading from compressed SquashFS filesystem.
Please see my original message in Fedora kernel mailing list archive:
https://lists.fedoraproject.org/archives/list/kernel@lists.fedoraproject....
There you can find an excerpt from Linux documentation for the changed options.
I found the disparity while working on Fedora change proposal:
https://fedoraproject.org/wiki/Changes/OptimizeSquashFS
Signed-off-by: Bohdan Khomutskyi <bkhomuts(a)redhat.com>
---
.../{ark => common}/generic/CONFIG_SQUASHFS_DECOMP_MULTI_PERCPU | 0
.../{ark => common}/generic/CONFIG_SQUASHFS_DECOMP_SINGLE | 0
.../configs/{ark => common}/generic/CONFIG_SQUASHFS_FILE_CACHE | 0
.../configs/{ark => common}/generic/CONFIG_SQUASHFS_FILE_DIRECT | 0
.../configs/fedora/generic/CONFIG_SQUASHFS_DECOMP_MULTI_PERCPU | 1 -
redhat/configs/fedora/generic/CONFIG_SQUASHFS_DECOMP_SINGLE | 1 -
redhat/configs/fedora/generic/CONFIG_SQUASHFS_FILE_CACHE | 1 -
redhat/configs/fedora/generic/CONFIG_SQUASHFS_FILE_DIRECT | 1 -
8 files changed, 4 deletions(-)
rename redhat/configs/{ark => common}/generic/CONFIG_SQUASHFS_DECOMP_MULTI_PERCPU
(100%)
rename redhat/configs/{ark => common}/generic/CONFIG_SQUASHFS_DECOMP_SINGLE (100%)
rename redhat/configs/{ark => common}/generic/CONFIG_SQUASHFS_FILE_CACHE (100%)
rename redhat/configs/{ark => common}/generic/CONFIG_SQUASHFS_FILE_DIRECT (100%)
delete mode 100644 redhat/configs/fedora/generic/CONFIG_SQUASHFS_DECOMP_MULTI_PERCPU
delete mode 100644 redhat/configs/fedora/generic/CONFIG_SQUASHFS_DECOMP_SINGLE
delete mode 100644 redhat/configs/fedora/generic/CONFIG_SQUASHFS_FILE_CACHE
delete mode 100644 redhat/configs/fedora/generic/CONFIG_SQUASHFS_FILE_DIRECT
diff --git a/redhat/configs/ark/generic/CONFIG_SQUASHFS_DECOMP_MULTI_PERCPU
b/redhat/configs/common/generic/CONFIG_SQUASHFS_DECOMP_MULTI_PERCPU
similarity index 100%
rename from redhat/configs/ark/generic/CONFIG_SQUASHFS_DECOMP_MULTI_PERCPU
rename to redhat/configs/common/generic/CONFIG_SQUASHFS_DECOMP_MULTI_PERCPU
diff --git a/redhat/configs/ark/generic/CONFIG_SQUASHFS_DECOMP_SINGLE
b/redhat/configs/common/generic/CONFIG_SQUASHFS_DECOMP_SINGLE
similarity index 100%
rename from redhat/configs/ark/generic/CONFIG_SQUASHFS_DECOMP_SINGLE
rename to redhat/configs/common/generic/CONFIG_SQUASHFS_DECOMP_SINGLE
diff --git a/redhat/configs/ark/generic/CONFIG_SQUASHFS_FILE_CACHE
b/redhat/configs/common/generic/CONFIG_SQUASHFS_FILE_CACHE
similarity index 100%
rename from redhat/configs/ark/generic/CONFIG_SQUASHFS_FILE_CACHE
rename to redhat/configs/common/generic/CONFIG_SQUASHFS_FILE_CACHE
diff --git a/redhat/configs/ark/generic/CONFIG_SQUASHFS_FILE_DIRECT
b/redhat/configs/common/generic/CONFIG_SQUASHFS_FILE_DIRECT
similarity index 100%
rename from redhat/configs/ark/generic/CONFIG_SQUASHFS_FILE_DIRECT
rename to redhat/configs/common/generic/CONFIG_SQUASHFS_FILE_DIRECT
diff --git a/redhat/configs/fedora/generic/CONFIG_SQUASHFS_DECOMP_MULTI_PERCPU
b/redhat/configs/fedora/generic/CONFIG_SQUASHFS_DECOMP_MULTI_PERCPU
deleted file mode 100644
index 123cbd7db973..000000000000
--- a/redhat/configs/fedora/generic/CONFIG_SQUASHFS_DECOMP_MULTI_PERCPU
+++ /dev/null
@@ -1 +0,0 @@
-# CONFIG_SQUASHFS_DECOMP_MULTI_PERCPU is not set
diff --git a/redhat/configs/fedora/generic/CONFIG_SQUASHFS_DECOMP_SINGLE
b/redhat/configs/fedora/generic/CONFIG_SQUASHFS_DECOMP_SINGLE
deleted file mode 100644
index 5978a504eaec..000000000000
--- a/redhat/configs/fedora/generic/CONFIG_SQUASHFS_DECOMP_SINGLE
+++ /dev/null
@@ -1 +0,0 @@
-CONFIG_SQUASHFS_DECOMP_SINGLE=y
diff --git a/redhat/configs/fedora/generic/CONFIG_SQUASHFS_FILE_CACHE
b/redhat/configs/fedora/generic/CONFIG_SQUASHFS_FILE_CACHE
deleted file mode 100644
index 15b6bd660cf8..000000000000
--- a/redhat/configs/fedora/generic/CONFIG_SQUASHFS_FILE_CACHE
+++ /dev/null
@@ -1 +0,0 @@
-CONFIG_SQUASHFS_FILE_CACHE=y
diff --git a/redhat/configs/fedora/generic/CONFIG_SQUASHFS_FILE_DIRECT
b/redhat/configs/fedora/generic/CONFIG_SQUASHFS_FILE_DIRECT
deleted file mode 100644
index 50eff586df28..000000000000
--- a/redhat/configs/fedora/generic/CONFIG_SQUASHFS_FILE_DIRECT
+++ /dev/null
@@ -1 +0,0 @@
-# CONFIG_SQUASHFS_FILE_DIRECT is not set
--
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