From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yang Xu Date: Thu, 23 Apr 2020 18:30:09 +0800 Subject: [LTP] [PATCH v4 3/3] syscalls/pipe2_03: Add new test for pipe2 O_DIRECT flag In-Reply-To: References: <1587552329-21738-1-git-send-email-xuyang2018.jy@cn.fujitsu.com> <1587552329-21738-3-git-send-email-xuyang2018.jy@cn.fujitsu.com> <662aa817-04ff-e924-6880-7c23fa1cfe31@cn.fujitsu.com> Message-ID: <3268f153-6730-708f-ed93-19ca4cf85fdd@cn.fujitsu.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: ltp@lists.linux.it Hi LI > > > On Thu, Apr 23, 2020 at 4:45 PM Yang Xu > wrote: > > ... > > I got a failure on the ppc64le platform(page size: 65536kB). > > > > # ./pipe2_03 > > tst_test.c:1246: INFO: Timeout per run is 0h 05m 00s > > pipe_size = 1048576 > > PIPE_BUF = 4096 > > packet_num = 256 > > safe_macros.c:457: BROK: pipe2_03.c:58: > > write(4,0x1001d2b8,18446744073709551615) failed: > EAGAIN/EWOULDBLOCK (11) > I think we should remove PIPE_BUF and use page_size? because we use a > page to store data not a fixed size buffer in kernel. as below(also, > man-pages[1] is need to update): > > > Emm, If PIPE_BUF doesn't work correctly, shouldn't this a kernel pipe > bug? I think we need to take a close look at what happened there but not > to replace by?using page_size directly. > -- It is only defined in limit.h(I only think it is a error in limit.h) and PIPE_BUF doesn't be used in kernel. In kernel code, pipes use struct pipe_buffer to store buffer data and other info, struct pipe_buffer { struct page *page; //alloc page to store data unsigned int offset, len; const struct pipe_buf_operations *ops; unsigned int flags; // unsigned long private; }; as my pipe2_01.c said we only make buf with PIPE_BUF_FLAG_PACKET flag in write end , and read will check this flag. This unit is a page instead of this PIPE_BUF macro. Best Regards Yang Xu > Regards, > Li Wang