From: Hao Xu <[email protected]>
To: Pavel Begunkov <[email protected]>, Jens Axboe <[email protected]>
Cc: [email protected], Joseph Qi <[email protected]>
Subject: Re: [PATCH v2] add tests for drain io with multishot reqs
Date: Tue, 27 Apr 2021 14:48:52 +0800 [thread overview]
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>
在 2021/4/14 下午6:48, Pavel Begunkov 写道:
> On 13/04/2021 08:23, Hao Xu wrote:
>> Add a simple test for drain io with multishot reqs. A generic one as
>> well, which randomly generates sqes for testing. The later will cover
>> most cases.
>
> Great job crafting tests and patches. It's a fix, so ok to get it in
> later RCs, so I'll take a look but in a week (if Jens won't take it
> earlier).
>
ping..
>>
>> Signed-off-by: Hao Xu <[email protected]>
>> ---
>> src/include/liburing/io_uring.h | 15 ++
>> test/Makefile | 2 +
>> test/multicqes_drain.c | 380 ++++++++++++++++++++++++++++++++++++++++
>> 3 files changed, 397 insertions(+)
>> create mode 100644 test/multicqes_drain.c
>>
>> diff --git a/src/include/liburing/io_uring.h b/src/include/liburing/io_uring.h
>> index d3d166e57be8..eed991d08655 100644
>> --- a/src/include/liburing/io_uring.h
>> +++ b/src/include/liburing/io_uring.h
>> @@ -165,6 +165,21 @@ enum {
>> #define SPLICE_F_FD_IN_FIXED (1U << 31) /* the last bit of __u32 */
>>
>> /*
>> + * POLL_ADD flags. Note that since sqe->poll_events is the flag space, the
>> + * command flags for POLL_ADD are stored in sqe->len.
>> + *
>> + * IORING_POLL_ADD_MULTI Multishot poll. Sets IORING_CQE_F_MORE if
>> + * the poll handler will continue to report
>> + * CQEs on behalf of the same SQE.
>> + *
>> + * IORING_POLL_UPDATE Update existing poll request, matching
>> + * sqe->addr as the old user_data field.
>> + */
>> +#define IORING_POLL_ADD_MULTI (1U << 0)
>> +#define IORING_POLL_UPDATE_EVENTS (1U << 1)
>> +#define IORING_POLL_UPDATE_USER_DATA (1U << 2)
>> +
>> +/*
>> * IO completion data structure (Completion Queue Entry)
>> */
>> struct io_uring_cqe {
>> diff --git a/test/Makefile b/test/Makefile
>> index 210571c22b40..5ffad0309914 100644
>> --- a/test/Makefile
>> +++ b/test/Makefile
>> @@ -66,6 +66,7 @@ test_targets += \
>> link-timeout \
>> link_drain \
>> madvise \
>> + multicqes_drain \
>> nop \
>> nop-all-sizes \
>> open-close \
>> @@ -202,6 +203,7 @@ test_srcs := \
>> link.c \
>> link_drain.c \
>> madvise.c \
>> + multicqes_drain.c \
>> nop-all-sizes.c \
>> nop.c \
>> open-close.c \
>> diff --git a/test/multicqes_drain.c b/test/multicqes_drain.c
>> new file mode 100644
>> index 000000000000..4f657e5c444a
>> --- /dev/null
>> +++ b/test/multicqes_drain.c
>> @@ -0,0 +1,380 @@
>> +/* SPDX-License-Identifier: MIT */
>> +/*
>> + * Description: generic tests for io_uring drain io
>> + *
>> + * The main idea is to randomly generate different type of sqe to
>> + * challenge the drain logic. There are some restrictions for the
>> + * generated sqes, details in io_uring maillist:
>> + * https://lore.kernel.org/io-uring/[email protected]/
>> + *
>> + */
>> +#include <errno.h>
>> +#include <stdio.h>
>> +#include <unistd.h>
>> +#include <stdlib.h>
>> +#include <string.h>
>> +#include <time.h>
>> +#include <sys/poll.h>
>> +
>> +#include "liburing.h"
>> +
>> +enum {
>> + multi,
>> + single,
>> + nop,
>> + cancel,
>> + op_last,
>> +};
>> +
>> +struct sqe_info {
>> + __u8 op;
>> + unsigned flags;
>> +};
>> +
>> +#define max_entry 50
>> +
>> +/*
>> + * sqe_flags: combination of sqe flags
>> + * multi_sqes: record the user_data/index of all the multishot sqes
>> + * cnt: how many entries there are in multi_sqes
>> + * we can leverage multi_sqes array for cancellation: we randomly pick
>> + * up an entry in multi_sqes when form a cancellation sqe.
>> + * multi_cap: limitation of number of multishot sqes
>> + */
>> +const unsigned sqe_flags[4] = {0, IOSQE_IO_LINK, IOSQE_IO_DRAIN,
>> + IOSQE_IO_LINK | IOSQE_IO_DRAIN};
>> +int multi_sqes[max_entry], cnt = 0;
>> +int multi_cap = max_entry / 5;
>> +
>> +int write_pipe(int pipe, char *str)
>> +{
>> + int ret;
>> + do {
>> + errno = 0;
>> + ret = write(pipe, str, 3);
>> + } while (ret == -1 && errno == EINTR);
>> + return ret;
>> +}
>> +
>> +void read_pipe(int pipe)
>> +{
>> + char str[4] = {0};
>> +
>> + read(pipe, &str, 3);
>> +}
>> +
>> +int trigger_event(int p[])
>> +{
>> + int ret;
>> + if ((ret = write_pipe(p[1], "foo")) != 3) {
>> + fprintf(stderr, "bad write return %d\n", ret);
>> + return 1;
>> + }
>> + read_pipe(p[0]);
>> + return 0;
>> +}
>> +
>> +void io_uring_sqe_prep(int op, struct io_uring_sqe *sqe, unsigned sqe_flags, int arg)
>> +{
>> + switch (op) {
>> + case multi:
>> + io_uring_prep_poll_add(sqe, arg, POLLIN);
>> + sqe->len |= IORING_POLL_ADD_MULTI;
>> + break;
>> + case single:
>> + io_uring_prep_poll_add(sqe, arg, POLLIN);
>> + break;
>> + case nop:
>> + io_uring_prep_nop(sqe);
>> + break;
>> + case cancel:
>> + io_uring_prep_poll_remove(sqe, (void *)(long)arg);
>> + break;
>> + }
>> + sqe->flags = sqe_flags;
>> +}
>> +
>> +__u8 generate_flags(int sqe_op)
>> +{
>> + __u8 flags = 0;
>> + /*
>> + * drain sqe must be put after multishot sqes cancelled
>> + */
>> + do {
>> + flags = sqe_flags[rand() % 4];
>> + } while ((flags & IOSQE_IO_DRAIN) && cnt);
>> +
>> + /*
>> + * cancel req cannot have drain or link flag
>> + */
>> + if (sqe_op == cancel) {
>> + flags &= ~(IOSQE_IO_DRAIN | IOSQE_IO_LINK);
>> + }
>> + /*
>> + * avoid below case:
>> + * sqe0(multishot, link)->sqe1(nop, link)->sqe2(nop)->sqe3(cancel_sqe0)
>> + * sqe3 may excute before sqe0 so that sqe0 isn't cancelled
>> + */
>> + if (sqe_op == multi)
>> + flags &= ~IOSQE_IO_LINK;
>> +
>> + return flags;
>> +
>> +}
>> +
>> +/*
>> + * function to generate opcode of a sqe
>> + * several restrictions here:
>> + * - cancel all the previous multishot sqes as soon as possible when
>> + * we reach high watermark.
>> + * - ensure there is some multishot sqe when generating a cancel sqe
>> + * - ensure a cancel/multshot sqe is not in a linkchain
>> + * - ensure number of multishot sqes doesn't exceed multi_cap
>> + * - don't generate multishot sqes after high watermark
>> + */
>> +int generate_opcode(int i, int pre_flags)
>> +{
>> + int sqe_op;
>> + int high_watermark = max_entry - max_entry / 5;
>> + bool retry0 = false, retry1 = false, retry2 = false;
>> +
>> + if ((i >= high_watermark) && cnt) {
>> + sqe_op = cancel;
>> + } else {
>> + do {
>> + sqe_op = rand() % op_last;
>> + retry0 = (sqe_op == cancel) && (!cnt || (pre_flags & IOSQE_IO_LINK));
>> + retry1 = (sqe_op == multi) && ((multi_cap - 1 < 0) || i >= high_watermark);
>> + retry2 = (sqe_op == multi) && (pre_flags & IOSQE_IO_LINK);
>> + } while (retry0 || retry1 || retry2);
>> + }
>> +
>> + if (sqe_op == multi)
>> + multi_cap--;
>> + return sqe_op;
>> +}
>> +
>> +inline void add_multishot_sqe(int index)
>> +{
>> + multi_sqes[cnt++] = index;
>> +}
>> +
>> +int remove_multishot_sqe()
>> +{
>> + int ret;
>> +
>> + int rem_index = rand() % cnt;
>> + ret = multi_sqes[rem_index];
>> + multi_sqes[rem_index] = multi_sqes[cnt - 1];
>> + cnt--;
>> +
>> + return ret;
>> +}
>> +
>> +static int test_generic_drain(struct io_uring *ring)
>> +{
>> + struct io_uring_cqe *cqe;
>> + struct io_uring_sqe *sqe[max_entry];
>> + struct sqe_info si[max_entry];
>> + int cqe_data[max_entry << 1], cqe_res[max_entry << 1];
>> + int i, j, ret, arg = 0;
>> + int pipes[max_entry][2];
>> + int pre_flags = 0;
>> +
>> + for (i = 0; i < max_entry; i++) {
>> + if (pipe(pipes[i]) != 0) {
>> + perror("pipe");
>> + return 1;
>> + }
>> + }
>> +
>> + srand((unsigned)time(NULL));
>> + for (i = 0; i < max_entry; i++) {
>> + sqe[i] = io_uring_get_sqe(ring);
>> + if (!sqe[i]) {
>> + printf("get sqe failed\n");
>> + goto err;
>> + }
>> +
>> + int sqe_op = generate_opcode(i, pre_flags);
>> + __u8 flags = generate_flags(sqe_op);
>> +
>> + if (sqe_op == cancel)
>> + arg = remove_multishot_sqe();
>> + if (sqe_op == multi || sqe_op == single)
>> + arg = pipes[i][0];
>> + io_uring_sqe_prep(sqe_op, sqe[i], flags, arg);
>> + sqe[i]->user_data = i;
>> + si[i].op = sqe_op;
>> + si[i].flags = flags;
>> + pre_flags = flags;
>> + if (sqe_op == multi)
>> + add_multishot_sqe(i);
>> + }
>> +
>> + ret = io_uring_submit(ring);
>> + if (ret < 0) {
>> + printf("sqe submit failed\n");
>> + goto err;
>> + } else if (ret < max_entry) {
>> + printf("Submitted only %d\n", ret);
>> + goto err;
>> + }
>> +
>> + sleep(4);
>> + // TODO: randomize event triggerring order
>> + for (i = 0; i < max_entry; i++) {
>> + if (si[i].op != multi && si[i].op != single)
>> + continue;
>> +
>> + if (trigger_event(pipes[i]))
>> + goto err;
>> + }
>> + sleep(5);
>> + i = 0;
>> + while (!io_uring_peek_cqe(ring, &cqe)) {
>> + cqe_data[i] = cqe->user_data;
>> + cqe_res[i++] = cqe->res;
>> + io_uring_cqe_seen(ring, cqe);
>> + }
>> +
>> + /*
>> + * compl_bits is a bit map to record completions.
>> + * eg. sqe[0], sqe[1], sqe[2] fully completed
>> + * then compl_bits is 000...00111b
>> + *
>> + */
>> + unsigned long long compl_bits = 0;
>> + for (j = 0; j < i; j++) {
>> + int index = cqe_data[j];
>> + if ((si[index].flags & IOSQE_IO_DRAIN) && index) {
>> + if ((~compl_bits) & ((1ULL << index) - 1)) {
>> + printf("drain failed\n");
>> + goto err;
>> + }
>> + }
>> + /*
>> + * for multishot sqes, record them only when it is cancelled
>> + */
>> + if ((si[index].op != multi) || (cqe_res[j] == -ECANCELED))
>> + compl_bits |= (1ULL << index);
>> + }
>> +
>> + return 0;
>> +err:
>> + return 1;
>> +}
>> +
>> +static int test_simple_drain(struct io_uring *ring)
>> +{
>> + struct io_uring_cqe *cqe;
>> + struct io_uring_sqe *sqe[2];
>> + int i, ret;
>> + int pipe1[2], pipe2[2];
>> +
>> + if (pipe(pipe1) != 0 || pipe(pipe2) != 0) {
>> + perror("pipe");
>> + return 1;
>> + }
>> +
>> + for (i = 0; i < 2; i++) {
>> + sqe[i] = io_uring_get_sqe(ring);
>> + if (!sqe[i]) {
>> + printf("get sqe failed\n");
>> + goto err;
>> + }
>> + }
>> +
>> + io_uring_prep_poll_add(sqe[0], pipe1[0], POLLIN);
>> + sqe[0]->len |= IORING_POLL_ADD_MULTI;
>> + sqe[0]->user_data = 0;
>> + io_uring_prep_poll_add(sqe[1], pipe2[0], POLLIN);
>> + sqe[1]->user_data = 1;
>> +
>> + ret = io_uring_submit(ring);
>> + if (ret < 0) {
>> + printf("sqe submit failed\n");
>> + goto err;
>> + } else if (ret < 2) {
>> + printf("Submitted only %d\n", ret);
>> + goto err;
>> + }
>> +
>> + for (i = 0; i < 2; i++) {
>> + if (trigger_event(pipe1))
>> + goto err;
>> + }
>> + if (trigger_event(pipe2))
>> + goto err;
>> +
>> + for (i = 0; i < 2; i++) {
>> + sqe[i] = io_uring_get_sqe(ring);
>> + if (!sqe[i]) {
>> + printf("get sqe failed\n");
>> + goto err;
>> + }
>> + }
>> +
>> + io_uring_prep_poll_remove(sqe[0], 0);
>> + sqe[0]->user_data = 2;
>> + io_uring_prep_nop(sqe[1]);
>> + sqe[1]->flags |= IOSQE_IO_DRAIN;
>> + sqe[1]->user_data = 3;
>> +
>> + ret = io_uring_submit(ring);
>> + if (ret < 0) {
>> + printf("sqe submit failed\n");
>> + goto err;
>> + } else if (ret < 2) {
>> + printf("Submitted only %d\n", ret);
>> + goto err;
>> + }
>> +
>> +
>> + for (i = 0; i < 6; i++) {
>> + ret = io_uring_wait_cqe(ring, &cqe);
>> + if (ret < 0) {
>> + printf("wait completion %d\n", ret);
>> + goto err;
>> + }
>> + io_uring_cqe_seen(ring, cqe);
>> + if ((i == 5) && (cqe->user_data != 3))
>> + goto err;
>> + }
>> +
>> + return 0;
>> +err:
>> + return 1;
>> +}
>> +
>> +int main(int argc, char *argv[])
>> +{
>> + struct io_uring ring;
>> + int i, ret;
>> +
>> + if (argc > 1)
>> + return 0;
>> +
>> + ret = io_uring_queue_init(1024, &ring, 0);
>> + if (ret) {
>> + printf("ring setup failed\n");
>> + return 1;
>> + }
>> +
>> + for (i = 0; i < 5; i++) {
>> + ret = test_simple_drain(&ring);
>> + if (ret) {
>> + fprintf(stderr, "test_simple_drain failed\n");
>> + break;
>> + }
>> + }
>> +
>> + for (i = 0; i < 5; i++) {
>> + ret = test_generic_drain(&ring);
>> + if (ret) {
>> + fprintf(stderr, "test_generic_drain failed\n");
>> + break;
>> + }
>> + }
>> + return ret;
>> +}
>>
>
next prev parent reply other threads:[~2021-04-27 6:48 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-13 7:20 [PATCH v3] io_uring: maintain drain logic for multishot poll requests Hao Xu
2021-04-13 7:23 ` [PATCH v2] add tests for drain io with multishot reqs Hao Xu
2021-04-14 10:48 ` Pavel Begunkov
2021-04-27 6:48 ` Hao Xu [this message]
2021-04-27 13:40 ` [PATCH v3] io_uring: maintain drain logic for multishot poll requests Jens Axboe
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