| Message ID | 01000163b674b125-d5dd17be-2896-4433-a9e2-863037c2b31a-000000@email.amazonses.com |
|---|---|
| State | New |
| Headers | show |
| Series | [Bug,3867] New: timer validation test fails when using 1GB huge pages | expand |
diff --git a/platform/linux-generic/odp_ishm.c b/platform/linux-generic/odp_ishm.c index fc2f948c..8c40399d 100644 --- a/platform/linux-generic/odp_ishm.c +++ b/platform/linux-generic/odp_ishm.c @@ -969,6 +969,8 @@ int _odp_ishm_reserve(const char *name, uint64_t size, int fd, return -1; } + *((int *)addr) = 0; + /* remember block data and increment block seq number to mark change */ new_block->len = len;
https://bugs.linaro.org/show_bug.cgi?id=3867 Bug ID: 3867 Summary: timer validation test fails when using 1GB huge pages Product: OpenDataPlane - linux- generic reference Version: v1.15.0.0 Hardware: Other OS: Linux Status: UNCONFIRMED Severity: enhancement Priority: --- Component: Timers Assignee: lng-odp@lists.linaro.org Reporter: josep.puigdemont@linaro.org CC: lng-odp@lists.linaro.org Target Milestone: --- As mentioned in comment #2 in bug 3774, the timer validation tests fails when using 1GB huge pages. It seems that the kernel zeroes-out the page before handing it out to user space, and this seems to be done at the first write to the page, that is, once it is committed (initially the page is only reserved). For 2MB huge pages the procedure may be fast enough, but for 1GB pages it seems to be too time consuming, and may be the reason the first timer is delayed, causing the test to fail. To check this a patch that "touches" a page when it is mapped was tried: new_block->user_len = size; This patch makes the timer test succeed again with 1GB huge pages, but causes shmem_linux to fail. The reason is that the shared memory file is opened by two different processes, one writes some well known data into it, which is read by the other one. The problem is that the second process, when creating the shared memory, now writes a zero where something else is expected to be read later. -- You are receiving this mail because: You are on the CC list for the bug. You are the assignee for the bug.