Messages in this thread | | | Date | Mon, 30 Oct 2023 15:40:55 +0000 | Subject | Re: [PATCH v2] docs: filesystems: document the squashfs specific mount options | From | Phillip Lougher <> |
| |
On 30/10/2023 12:57, Ariel Miculas wrote: > On 23/10/29 08:33PM, Phillip Lougher wrote: >> On 29/10/2023 16:19, Ariel Miculas wrote: >>> When SQUASHFS_CHOICE_DECOMP_BY_MOUNT is set, the "threads" mount option >>> can be used to specify the decompression mode: single-threaded, >>> multi-threaded, percpu or the number of threads used for decompression. >>> When SQUASHFS_CHOICE_DECOMP_BY_MOUNT is not set and >>> SQUASHFS_DECOMP_MULTI is set, the "threads" option can also be used to >>> specify the number of threads used for decompression. This mount option >>> is only mentioned in fs/squashfs/Kconfig, which makes it difficult to >>> find. >>> >>> Another mount option available is "errors", which can be configured to >>> panic the kernel when squashfs errors are encountered. >>> >>> Add both these options to the squashfs documentation, making them more >>> noticeable. >>> >>> Signed-off-by: Ariel Miculas <amiculas@cisco.com> >> >> Looks good to me. >> >> Reviewed-by: Phillip Lougher <phillip@squashfs.org.uk> > > Unfortunately, it seems this is not quite correct either: > There is the config option SQUASHFS_MOUNT_DECOMP_THREADS: > ``` > bool "Add the mount parameter 'threads=' for squashfs" > depends on SQUASHFS > depends on SQUASHFS_DECOMP_MULTI > default n > help > Use threads= to set the decompression parallel mode and the number of threads. > If SQUASHFS_CHOICE_DECOMP_BY_MOUNT=y > threads=<single|multi|percpu|1|2|3|...> > else > threads=<2|3|...> > The upper limit is num_online_cpus() * 2. > ``` > that depends on SQUASHFS_DECOMP_MULTI. > So I think I should take my v1 patch and specify that the "threads=" > mount option depends on SQUASHFS_MOUNT_DECOMP_THREADS. There's no need > to specify SQUASHFS_DECOMP_MULTI, because SQUASHFS_MOUNT_DECOMP_THREADS > already depends on it.
Sorry, you have to specify SQUASHFS_DECOMP_MULTI to be able to specify SQUASHFS_MOUNT_DECOMP_THREADS if SQUASHFS_DECOMP_BY_MOUNT is unselected.
Just try it, do make menuconfig, ensure SQUASHFS_CHOICE_DECOMP_BY_MOUNT is unselected, select Single threaded decompression and you won't be able to specify SQUASHFS_MOUNT_DECOMP_THREADS.
That was the point of my review. What bit don't you understand?
Phillip
> What do you think? > > Regards, > Ariel >
| |