On 2018/7/31 9:35, Dominique Martinet wrote: > piaojun wrote on Tue, Jul 31, 2018: >> Could you help paste some test result before-and-after the patch applied? > > The only performance tests I did were sent to the list a couple of mails > earlier, you can find it here: > http://lkml.kernel.org/r/20180730093101.GA7894@nautica > > In particular, the results for benchmark on small writes just before and > after this patch, without KASAN (these are the same numbers as in the > link, hardware/setup is described there): > - no alloc (4.18-rc7 request cache): 65.4k req/s > - non-power of two alloc, no patch: 61.6k req/s > - power of two alloc, no patch: 62.2k req/s > - non-power of two alloc, with patch: 64.7k req/s > - power of two alloc, with patch: 65.1k req/s > > I'm rather happy with the result, I didn't expect using a dedicated > cache would bring this much back but it's certainly worth it. > It looks like an obvious promotion. >>> @@ -1011,6 +1034,7 @@ void p9_client_destroy(struct p9_client *clnt) >>> >>> p9_tag_cleanup(clnt); >>> >>> + kmem_cache_destroy(clnt->fcall_cache); >> >> We could set NULL for fcall_cache in case of use-after-free. >> >>> kfree(clnt); > > Hmm, I understand where this comes from, but I'm not sure I agree. > If someone tries to access the client while/after it is freed things are > going to break anyway, I'd rather let things break as obviously as > possible than try to cover it up. > Setting NULL is not a big matter, and I will hear others' opinion.
