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DIR:OUT; SFP:1102; SCL:1; SRVR:BY5PR18MB3204; H:BY5PR18MB3122.namprd18.prod.outlook.com; FPR:; SPF:None; LANG:en; PTR:InfoNoRecords; MX:1; A:1; received-spf: None (protection.outlook.com: suse.com does not designate permitted sender hosts) x-ms-exchange-senderadcheck: 1 x-microsoft-antispam: BCL:0; x-microsoft-antispam-message-info: KAzpv1Bw8h0fWTvyC32KzJvaEHqjh17usfimhpB5hUqiZp2hBPLB8a+2FGNWxKmbiOlQ4w2wKcUY5MEfUIARBhZqUuJDoS5VqUXDraOqV7TNiqf7OhZwmCigaL6Lk5OgnEJlO4M2f5cgFTOQy0cJ+vzdXkQAwRM487ixJNUoEMJc+UaB/QneIfOZzJQGbGGUHvrJZU0S9nGyrXq5L6LOA1H8zv11hFUD7WMlBmkxOiq597q8jq30sP4mKNuniuBWyblSo4EKwToDX0tath8YsC7UMfijvCtpW2AIVOcKY8Hb+zidB0ci7X1XrTsFBJvnUIjl5hFP1E3Ak86N2XKBflVlk4aN4l7z3c5ke9iYIOcdxLSmCMX//X+YJ2jYWwAkh1/zNaokeq5TsozeUbSLkNLXIjSuFPKFCOr2vmfZjA8lbipD5MCnLkG2lYSxbgC0Qd3kT1pxN18lYLK7RJClbWkniGTl1I+91k4NzpAudj4= Content-Type: text/plain; charset="us-ascii" Content-ID: <5BD5D262DCE182439B95EC8FFCC69B8F@namprd18.prod.outlook.com> Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-MS-Exchange-CrossTenant-Network-Message-Id: e64c7470-1824-4208-d536-08d7634c8163 X-MS-Exchange-CrossTenant-originalarrivaltime: 07 Nov 2019 06:34:13.8010 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: 856b813c-16e5-49a5-85ec-6f081e13b527 X-MS-Exchange-CrossTenant-mailboxtype: HOSTED X-MS-Exchange-CrossTenant-userprincipalname: 4q3Hv86YDVmye7z9PPeUwHlxajNj1SqTjNq7Tr5RotwX4xdD6Wom3q9kImbpImE+ X-MS-Exchange-Transport-CrossTenantHeadersStamped: BY5PR18MB3204 X-OriginatorOrg: suse.com X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 15.124.2.85 X-BeenThere: grub-devel@gnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: The development of GNU GRUB List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 07 Nov 2019 06:34:34 -0000 On Wed, Nov 06, 2019 at 01:40:30PM +0100, David Sterba wrote: > On Tue, Nov 05, 2019 at 09:19:59AM +0000, Michael Chang wrote: > > The zstd support in btrfs has dependenciy to zstd module and core.img > > grows its size significantly to 75KB on my system. The resulted image > > cannot be installed into btrfs bootloader area in the size of 64KB and > > eventually fails with following message. > >=20 > > /usr/sbin/grub-install: warning: your core.img is unusually large. It > > won't fit in the embedding area. > > /usr/sbin/grub-install: error: filesystem `btrfs' doesn't support > > blocklists. > >=20 > > The patch disabled the zstd support of btrfs in pc-bios platform to > > avoid the regression. The resulting size is 56KB, albeit a bit too clos= e > > to the 64KB but works. This is simple workaround until a proper fix > > landed upstream. >=20 > So combination zstd+btrfs+i386-pc never worked? It works for mbr gap, however we used to encounter some system shipped by Microsoft Windows still having its mbr gap aligned to cylinder boundary, which is usually 63 sectors. Therefore we could only fallback to btrfs bootloader area if mbr gap is found to be too small and now that the solution is no longer appropriate. > Removing support for > zstd could lead to unbootable system, but if that has never worked > before it'd be ok to make the build conditional. So far didn't have the request to enable btrfs zstd compression for the root filesystem. But with new grub supporting it, the request might come up in the future and hope we could have solution for i386-pc at that time. >=20 > Looking at zstd code, does not seem to be easy to squeeze the asm to > something like 64-56=3D8K. Another solution from Vladmir is making the zstd support a separate module and loading on demand. I personally think it is better than reducing the size as the same situation could still come up in the future. Thanks, Michael >=20 > _______________________________________________ > Grub-devel mailing list > Grub-devel@gnu.org > https://lists.gnu.org/mailman/listinfo/grub-devel