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    SubjectRe: ping //Re: [PATCH v2 0/2] squashfs: Add the mount parameter "threads="
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    On 30/08/2022 19:08, Phillip Lougher wrote:
    > On 30/08/2022 14:38, Xiaoming Ni wrote:
    >> On 2022/8/29 7:18, Phillip Lougher wrote:

    >>> As regards points 1 - 3, personally I would add a default kernel
    >>> configuration option that keeps the existing behaviour, build time
    >>> selectable only, no additional mount time options.  Then a
    >>> kernel configuration option that allows the different decompressors
    >>> to be selected at mount time, but which always builds all the
    >>> decompressors.  This will avoid the silliness of point 2, and
    >> Would it be better to allow flexible selection of decompression mode
    >> combinations?
    >
    > I told you I don't like that (*).  I also told you I want the default
    > behaviour to be the current behaviour.
    >
    > Feel free to disagree, but that isn't a good way to get your patch
    > reviewed or accepted by me.
    >
    > Cheers
    >
    > Phillip
    >
    > (*) Adding options to select the decompressor at mount time, but,
    >     also allowing only 1 - 2 decompressors to be built is a waste of
    >     time.  It has the effect of giving something with one hand and
    >     taking it alway with the other.  Build the lot, this also
    >     keeps it simple.
    >
    >

    It also splatters super.c with #ifdef CONFIG lines.

    phillip@phoenix:/external/stripe/linux/fs/squashfs$ grep "CONFIG_" super.c
    #ifdef CONFIG_SQUASHFS_DECOMP_SINGLE
    #ifdef CONFIG_SQUASHFS_DECOMP_MULTI
    #ifdef CONFIG_SQUASHFS_DECOMP_MULTI_PERCPU
    #ifdef CONFIG_SQUASHFS_DECOMP_SINGLE
    #ifdef CONFIG_SQUASHFS_DECOMP_MULTI
    #ifdef CONFIG_SQUASHFS_DECOMP_MULTI_PERCPU
    #ifdef CONFIG_SQUASHFS_DECOMP_DEFAULT_SINGLE
    #elif defined(CONFIG_SQUASHFS_DECOMP_DEFAULT_MULTI)
    #elif defined(CONFIG_SQUASHFS_DECOMP_DEFAULT_PERCPU)

    Or

    static int squashfs_parse_param_threads(const char *str, struct
    squashfs_mount_opts *opts)
    {
    unsigned long num;
    int ret;
    #ifdef CONFIG_SQUASHFS_DECOMP_SINGLE
    if (strcmp(str, "single") == 0) {
    opts->thread_ops = &squashfs_decompressor_single;
    return 0;
    }
    #endif
    #ifdef CONFIG_SQUASHFS_DECOMP_MULTI
    if (strcmp(str, "multi") == 0) {
    opts->thread_ops = &squashfs_decompressor_multi;
    return 0;
    }
    #endif
    #ifdef CONFIG_SQUASHFS_DECOMP_MULTI_PERCPU
    if (strcmp(str, "percpu") == 0) {
    opts->thread_ops = &squashfs_decompressor_percpu;
    return 0;
    }
    #endif
    ret = kstrtoul(str, 0, &num);
    if (ret != 0 || num == 0)
    return -EINVAL;
    #ifdef CONFIG_SQUASHFS_DECOMP_SINGLE
    if (num == 1) {
    opts->thread_ops = &squashfs_decompressor_single;
    return 0;
    }
    #endif
    #ifdef CONFIG_SQUASHFS_DECOMP_MULTI
    opts->thread_ops = &squashfs_decompressor_multi;
    if (num > opts->thread_ops->max_decompressors())
    num = opts->thread_ops->max_decompressors();
    opts->thread_num = (int)num;
    return 0;
    #else
    return -EINVAL;
    #endif
    }

    SNIP

    static int squashfs_show_options(struct seq_file *s, struct dentry *root)
    {
    struct super_block *sb = root->d_sb;
    struct squashfs_sb_info *msblk = sb->s_fs_info;

    if (msblk->panic_on_errors)
    seq_puts(s, ",errors=panic");
    else
    seq_puts(s, ",errors=continue");

    #ifdef CONFIG_SQUASHFS_DECOMP_MULTI_PERCPU
    /*
    * thread=percpu and thread=<number> have different
    configuration effects.
    * the parameters need to be treated differently when they are
    displayed.
    */
    if (msblk->thread_ops == &squashfs_decompressor_percpu) {
    seq_puts(s, ",threads=percpu");
    return 0;
    }
    #endif
    seq_printf(s, ",threads=%u", msblk->max_thread_num);
    return 0;
    }

    static int squashfs_init_fs_context(struct fs_context *fc)
    {
    struct squashfs_mount_opts *opts;

    opts = kzalloc(sizeof(*opts), GFP_KERNEL);
    if (!opts)
    return -ENOMEM;

    #ifdef CONFIG_SQUASHFS_DECOMP_DEFAULT_SINGLE
    opts->thread_ops = &squashfs_decompressor_single;
    #elif defined(CONFIG_SQUASHFS_DECOMP_DEFAULT_MULTI)
    opts->thread_ops = &squashfs_decompressor_multi,
    #elif defined(CONFIG_SQUASHFS_DECOMP_DEFAULT_PERCPU)
    opts->thread_ops = &squashfs_decompressor_percpu;
    #endif

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      Last update: 2022-08-30 20:35    [W:3.773 / U:0.668 seconds]
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