[LTP] [PATCH] swapon01: swapon01: prevent OOM happening in swap process

[Li Wang]

On Tue, Mar 19, 2024 at 1:04 PM Petr Vorel <pvorel@suse.cz> wrote:

> > On Mon, Mar 18, 2024 at 8:40 PM Wei Gao <wegao@suse.com> wrote:
>
>
>
>
> > > > That's because the available swapfile on your SUT is too small,
> > > > you can adjust it (then retest it) by yourself to find a proper size.
>
> > > > This is fine as long as the swapfile size is less than 300MB,
> > > > otherwise we need to set .dev_min_size like what we did
> > > > for swapoff01.c.
>
> > > > And, on the other side, we can't guarantee the system SwapCached
> > > > happened every time, it depends on the system's configuration.
>
>
> > > 100M is good enough for current system, could you help check following
> > > patch?
>
>
> > Can we rewrite the make_swapfile() API to support passing MB size for
> > making the swapfile?
>
> I guess it would be desirable (but keep also possible to pass that 10
> blocks,
> therefore maybe use flag to distinguish between MB and blocks?).
>

That's fine but a bit complex for users to distinguish flags.

Or, what about making the function use the flag as static, and
export two additional functions with MB and blocks?

enum swapfile_method {
    SWAPFILE_BY_SIZE,
    SWAPFILE_BY_BLOCKS
};

static int make_swapfile(const char *swapfile, unsigned int para, int safe,
enum swapfile_method method) {
    // The main logic to achieve the swapfile-making process
    // ...
}

int make_swapfile_size(const char *swapfile, unsigned int size, int safe) {
    return make_swapfile(swapfile, size, safe, SWAPFILE_BY_SIZE);
}

int make_swapfile_blks(const char *swapfile, unsigned int blocks, int safe)
{
    return make_swapfile(swapfile, blocks, safe, SWAPFILE_BY_BLOCKS);
}

-- 
Regards,
Li Wang