6.1-stable review patch. If anyone has any objections, please let me know.
------------------
From: Geert Uytterhoeven <geert+renesas@glider.be>
[ Upstream commit ab74edaeb1ae7c7194e79007e6afdfe788111a3f ]
When NR_CPUS is less than 16, or when SMP is disabled, the default value
of 16 is invalid.
While actual configuration picks up a sensible and valid default
(NR_CPUS or 1), "make savedefconfig" will still write a line like
CONFIG_EROFS_FS_ZIP_LZMA_DEFAULT_MAX_STREAMS=1
to the defconfig file, even if that matches the sensible default.
Avoid needlessly enlarging the defconfig files, and reduce churn for
updating them, by specifying valid defaults depending on SMP and
NR_CPUS.
While at it, make the prompt depend on SMP, as there is no point in
asking the user about the maximum number of decompression streams if
there is only one valid answer.
Fixes: c9b47e6b23114e93 ("erofs: cap LZMA stream pool size")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Gao Xiang <xiang@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/erofs/Kconfig | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/fs/erofs/Kconfig b/fs/erofs/Kconfig
index 01fdc78f03463..807df9b5a4902 100644
--- a/fs/erofs/Kconfig
+++ b/fs/erofs/Kconfig
@@ -100,11 +100,13 @@ config EROFS_FS_ZIP_LZMA
If unsure, say N.
config EROFS_FS_ZIP_LZMA_DEFAULT_MAX_STREAMS
- int "EROFS LZMA default maximum decompression streams"
+ int "EROFS LZMA default maximum decompression streams" if SMP
depends on EROFS_FS_ZIP_LZMA
range 1 NR_CPUS if SMP
range 1 1 if !SMP
- default 16
+ default 16 if SMP && NR_CPUS >= 16
+ default NR_CPUS if SMP
+ default 1
help
By default EROFS allocates one LZMA decompression stream per CPU.
Each stream can hold a dictionary of up to 8 MiB taken from the
@@ -112,7 +114,7 @@ config EROFS_FS_ZIP_LZMA_DEFAULT_MAX_STREAMS
of memory. This caps the default; the lzma_streams module parameter
still overrides it.
- If unsure, keep the default of 16.
+ If unsure, keep the suggested default (16 or lower).
config EROFS_FS_ONDEMAND
bool "EROFS fscache-based on-demand read support"
--
2.53.0