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SubjectRe: [RFC PATCH v5 1/3] printk-rb: new printk ringbuffer implementation (writer)
On (19/11/28 02:58), John Ogness wrote:
> + * Sample reader code::
> + *
> + * struct printk_info info;
> + * char text_buf[32];
> + * char dict_buf[32];
> + * u64 next_seq = 0;
> + * struct printk_record r = {
> + * .info = &info,
> + * .text_buf = &text_buf[0],
> + * .dict_buf = &dict_buf[0],
> + * .text_buf_size = sizeof(text_buf),
> + * .dict_buf_size = sizeof(dict_buf),
> + * };
> + *
> + * while (prb_read_valid(&rb, next_seq, &r)) {
> + * if (info.seq != next_seq)
> + * pr_warn("lost %llu records\n", info.seq - next_seq);
> + *
> + * if (info.text_len > r.text_buf_size) {
> + * pr_warn("record %llu text truncated\n", info.seq);
> + * text_buf[sizeof(text_buf) - 1] = 0;
> + * }
> + *
> + * if (info.dict_len > r.dict_buf_size) {
> + * pr_warn("record %llu dict truncated\n", info.seq);
> + * dict_buf[sizeof(dict_buf) - 1] = 0;
> + * }
> + *
> + * pr_info("%llu: %llu: %s;%s\n", info.seq, info.ts_nsec,
> + * &text_buf[0], info.dict_len ? &dict_buf[0] : "");
> + *
> + * next_seq = info.seq + 1;
> + * }
> + */

Will this loop ever end? :)

pr_info() adds data to ringbuffer, which prb_read_valid() reads, so pr_info()
can add more data, which prb_read_valid() will read, so pr_info()...

-ss

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