[Crash-utility] Re: Adding the zram decompression algorithm "lzo-rle" to support kernel versions >= 5.1

> Hi Yulong, > > Thanks for your patch! > > On Mon, Feb 26, 2024 at 3:20 PM Yulong TANG 汤玉龙 <yulong.tang(a)nio.com&gt; wrote: > > I have no objection to the lzo-rle decompression feature for crash. > However I have some concern of your patch: > > The patch you attached is a "lzorle_decompress_safe" implementation > which is copied from kernel source code. One of the drawbacks of > copying kernel source code is, kernel is constantly evolving, the code > you copied here today maybe updated someday later, and in support of > different kernel versions, we need to keep a bunch of > switch(kernel_version) and case code to keep the compatibility, which > is what we are trying to avoid. > > In addition, the code you copied has deliberately deleted the "if > defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)" part, which may also > cause some problem, and as far as I know, there is no good way in > crash to determine the kernel config status, please feel free to > correct me if I'm wrong. Hi Tao, I discovered that there seems to be an array called ikconfig_all in kernel.c which records the kernel config status, and there is an API called get_kernel_config(char *conf_name, char **str) for obtaining kernel configuration. This might help solve the second problem you raised. For example, adding a line: #define CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS get_kernel_config("CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS", NULL);

Thanks, Yulong -- Crash-utility mailing list -- devel(a)lists.crash-utility.osci.io To unsubscribe send an email to devel-leave(a)lists.crash-utility.osci.io https://${domain_name}/admin/lists/devel.lists.crash-utility.osci.io/ Contribution Guidelines: https://github.com/crash-utility/crash/wiki