RFR: 8247522: assert(is_aligned(class_space_rs.base(), class_space_alignment)) failed: Sanity
jiefu(傅杰)
jiefu at tencent.com
Mon Jun 15 06:46:34 UTC 2020
I plan to push it to jdk15 and then it will be merged into jdk/jdk automatically.
What do you think?
Best regards,
Jie
From: Thomas Stüfe <thomas.stuefe at gmail.com>
Date: Monday, June 15, 2020 at 2:32 PM
To: "jiefu(傅杰)" <jiefu at tencent.com>
Cc: Ioi Lam <ioi.lam at oracle.com>, "hotspot-runtime-dev at openjdk.java.net" <hotspot-runtime-dev at openjdk.java.net>
Subject: Re: RFR: 8247522: assert(is_aligned(class_space_rs.base(), class_space_alignment)) failed: Sanity(Internet mail)
Will you push it to head, then downport it to 15?
For that matter, how does this even work currently?
On Mon, Jun 15, 2020 at 8:22 AM jiefu(傅杰) <jiefu at tencent.com<mailto:jiefu at tencent.com>> wrote:
Thanks Ioi for your review.
I will push it later today.
Best regards,
Jie
On 2020/6/15, 1:57 PM, "hotspot-runtime-dev on behalf of Ioi Lam" <hotspot-runtime-dev-bounces at openjdk.java.net<mailto:hotspot-runtime-dev-bounces at openjdk.java.net> on behalf of ioi.lam at oracle.com<mailto:ioi.lam at oracle.com>> wrote:
Looks good to me, too.
Thanks
- Ioi
On 6/14/20 4:42 PM, jiefu(傅杰) wrote:
> Thanks Thomas for your review.
>
> May I get a second review for this change?
>
> Thanks a lot.
> Best regards,
> Jie
>
> From: Thomas Stüfe <thomas.stuefe at gmail.com<mailto:thomas.stuefe at gmail.com>>
> Date: Sunday, June 14, 2020 at 12:44 AM
> To: "jiefu(傅杰)" <jiefu at tencent.com<mailto:jiefu at tencent.com>>
> Cc: Hotspot dev runtime <hotspot-runtime-dev at openjdk.java.net<mailto:hotspot-runtime-dev at openjdk.java.net>>
> Subject: Re: RFR: 8247522: assert(is_aligned(class_space_rs.base(), class_space_alignment)) failed: Sanity(Internet mail)
>
> Looks good to me. Thanks for fixing it!
>
> .. Thomas
>
> On Sat, Jun 13, 2020, 17:14 jiefu(傅杰) <jiefu at tencent.com<mailto:jiefu at tencent.com><mailto:jiefu at tencent.com<mailto:jiefu at tencent.com>>> wrote:
> Hi Thomas,
>
> Thanks for your review and nice comments.
>
> The bug was first found on Linux/x86 machines with our Tencent tlinux OS.
>
> Updated: http://cr.openjdk.java.net/~jiefu/8247522/webrev.01/
>
> Your change is really cool.
> With your patch, I can even reproduce the bug on our macOS platforms.
>
> Thanks a lot.
> Best regards,
> Jie
>
> From: Thomas Stüfe <thomas.stuefe at gmail.com<mailto:thomas.stuefe at gmail.com><mailto:thomas.stuefe at gmail.com<mailto:thomas.stuefe at gmail.com>>>
> Date: Saturday, June 13, 2020 at 8:41 PM
> To: "jiefu(傅杰)" <jiefu at tencent.com<mailto:jiefu at tencent.com><mailto:jiefu at tencent.com<mailto:jiefu at tencent.com>>>
> Cc: "hotspot-runtime-dev at openjdk.java.net<mailto:hotspot-runtime-dev at openjdk.java.net><mailto:hotspot-runtime-dev at openjdk.java.net<mailto:hotspot-runtime-dev at openjdk.java.net>>" <hotspot-runtime-dev at openjdk.java.net<mailto:hotspot-runtime-dev at openjdk.java.net><mailto:hotspot-runtime-dev at openjdk.java.net<mailto:hotspot-runtime-dev at openjdk.java.net>>>
> Subject: Re: RFR: 8247522: assert(is_aligned(class_space_rs.base(), class_space_alignment)) failed: Sanity(Internet mail)
>
> Hi Jie,
>
> good catch! What platform did this occur on?
>
> Please remove the casts, you do not need them.
>
> Please add the following lines to your patch - these test modifications trigger the bug also on linux x64:
>
> ---------------
>
> diff -r 19b3969274ce test/hotspot/jtreg/runtime/cds/SharedBaseAddress.java
> --- a/test/hotspot/jtreg/runtime/cds/SharedBaseAddress.java Thu Jun 11 12:51:09 2020 +0200
> +++ b/test/hotspot/jtreg/runtime/cds/SharedBaseAddress.java Sat Jun 13 14:36:46 2020 +0200
> @@ -41,6 +41,7 @@
> "1g", "8g", "64g","512g", "4t",
> "32t", "128t", "0",
> "1", "64k", "64M",
> + "0x800001000", // Default base address + 1 page - probably valid but unaligned to metaspace alignment, see JDK 8247522
> "0xfffffffffff00000", // archive top wraps around 64-bit address space
> "0xfff80000", // archive top wraps around 32-bit address space
> "0xffffffffffffffff", // archive bottom wraps around 64-bit address space -- due to align_up()
> diff -r 19b3969274ce test/hotspot/jtreg/runtime/cds/appcds/SharedBaseAddress.java
> --- a/test/hotspot/jtreg/runtime/cds/appcds/SharedBaseAddress.java Thu Jun 11 12:51:09 2020 +0200
> +++ b/test/hotspot/jtreg/runtime/cds/appcds/SharedBaseAddress.java Sat Jun 13 14:36:46 2020 +0200
> @@ -41,7 +41,8 @@
> private static final String[] testTable = {
> "1g", "8g", "64g","512g", "4t",
> "32t", "128t", "0",
> - "1", "64k", "64M", "320g"
> + "1", "64k", "64M", "320g",
> + "0x800001000" // Default base address + 1 page - probably valid but unaligned to metaspace alignment, see JDK 8247522
> };
>
> public static void main(String[] args) throws Exception {
>
> ---------------
>
> Thanks, Thomas
>
>
> On Sat, Jun 13, 2020 at 11:44 AM jiefu(傅杰) <jiefu at tencent.com<mailto:jiefu at tencent.com><mailto:jiefu at tencent.com<mailto:jiefu at tencent.com>>> wrote:
> Hi all,
>
> JBS: https://bugs.openjdk.java.net/browse/JDK-8247522
> Webrev: http://cr.openjdk.java.net/~jiefu/8247522/webrev.00/
>
> This bug was triggered after JDK-8245707.
> The reason is that ccs_begin_offset[1] is incorrect when archive_space_alignment != class_space_alignment.
>
> Before JDK-8245707, archive_space_alignment = class_space_alignment = 4k.
> After JDK-8245707, archive_space_alignment = 4k, class_space_alignment = 16k.
>
> When the assert happened, we had observed base_address[2] = 4096, which is unaligned to class_space_alignment=16k.
>
> - Testing:
> tier1 on Linux/x64
>
> Thanks a lot.
> Best regards,
> Jie
>
> [1] http://hg.openjdk.java.net/jdk/jdk15/file/1c81917f228b/src/hotspot/share/memory/metaspaceShared.cpp#l2505
> [2] http://hg.openjdk.java.net/jdk/jdk15/file/1c81917f228b/src/hotspot/share/memory/metaspaceShared.cpp#l2514
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