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charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Spam-Level: X-Rspamd-Server: rspamd2.dmz-prg2.suse.org X-Spamd-Result: default: False [-3.50 / 50.00]; DWL_DNSWL_MED(-2.00)[suse.de:dkim]; NEURAL_HAM_LONG(-1.00)[-1.000]; R_DKIM_ALLOW(-0.20)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; NEURAL_HAM_SHORT(-0.20)[-1.000]; MIME_GOOD(-0.10)[text/plain]; XM_UA_NO_VERSION(0.01)[]; MX_GOOD(-0.01)[]; DKIM_SIGNED(0.00)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; FUZZY_BLOCKED(0.00)[rspamd.com]; RBL_SPAMHAUS_BLOCKED_OPENRESOLVER(0.00)[2a07:de40:b281:104:10:150:64:97:from]; ARC_NA(0.00)[]; TO_DN_SOME(0.00)[]; FREEMAIL_TO(0.00)[intel.com,linux.intel.com,kernel.org,gmail.com,ffwll.ch]; MIME_TRACE(0.00)[0:+]; TO_DN_EQ_ADDR_SOME(0.00)[]; FREEMAIL_ENVRCPT(0.00)[gmail.com]; RCVD_TLS_ALL(0.00)[]; DKIM_TRACE(0.00)[suse.de:+]; SPAMHAUS_XBL(0.00)[2a07:de40:b281:104:10:150:64:97:from]; FROM_EQ_ENVFROM(0.00)[]; FROM_HAS_DN(0.00)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; RCVD_COUNT_TWO(0.00)[2]; RCPT_COUNT_SEVEN(0.00)[9]; MID_RHS_MATCH_FROM(0.00)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; RECEIVED_SPAMHAUS_BLOCKED_OPENRESOLVER(0.00)[2a07:de40:b281:106:10:150:64:167:received]; DBL_BLOCKED_OPENRESOLVER(0.00)[suse.de:email,suse.de:dkim] X-Rspamd-Action: no action X-Spam-Flag: NO X-Spam-Score: -3.50 X-Rspamd-Queue-Id: 855591F7DB Hi Am 05.08.24 um 10:10 schrieb Zhuo, Qiuxu: > Hi Thomas, > >> From: Thomas Zimmermann >> Sent: Monday, August 5, 2024 3:31 PM >> [...] >>> Hi Maarten and maintainers, >>> >>> A gentle ping :-). >>> >>> Could you please help push this v2 fix upstream? >>> If you have any concerns, please let me know. >> I already acked this patch, but I still have a question: during a panic, will fbcon > Thanks for your kind review of this patch and ACK. > >> still print a panic message? I think that would likely require scheduling that >> worker. > During the error injection testing: > > 1) Without this v2 fix: > > 1.1) If panic() is not blocked on [1] (~99 times in 100 cycles), > then the console/fbcon can print normal panic-related messages like [2], > and the system can reboot successfully. > > 1.2) If panic() is blocked on [1] (~1 time in 100 cycles), > then the console/fbcon is silent and the system gets hung without reboot. > This is not the expected behavior. The system is expected to reboot. > > 2) With this v2 fix: > > 2.1) The console/fbcon can always print normal panic related messages like[2], > and the system can reboot successfully. Same behavior to 1.1). > [ we tested it ~1500 cycles. ] > > [1] panic() -> ... drm_fb_helper_damage() -> schedule_work(). > For details, pls see the v2 commit message. > > [2] Panic messages: > [ 133.900042] mce: [Hardware Error]: CPU 0: Machine Check Exception: 5 Bank 4: ba00000000000e0b > [ 133.900046] mce: [Hardware Error]: RIP !INEXACT! 10: {intel_idle_xstate+0x6c/0xc0} > [ 133.900055] mce: [Hardware Error]: TSC 9701dd289b MISC 29100000 PPIN 9000d7561bb0e340 > [ 133.900057] mce: [Hardware Error]: PROCESSOR 0:a06d1 TIME 1715827713 SOCKET 0 APIC 0 microcode 810001d0 > [ 133.900060] mce: [Hardware Error]: Run the above through 'mcelog --ascii' > [ 134.053858] mce: [Hardware Error]: Machine check: Processor context corrupt > [ 134.053866] Kernel panic - not syncing: Fatal machine check > [ 134.075183] Kernel Offset: disabled > [ 134.111372] pstore: backend (erst) writing error (-28) Thanks for the detailed reply. I've found that your patch has already been merged and should now be in v6.11-rc2. It'll probably be backported to older kernels as well. > dim cite 833cd3e9ad8360785b6c23c82dd3856df00732d9 833cd3e9ad83 ("drm/fb-helper: Don't schedule_work() to flush frame buffer during panic()") > git tag --contains 833cd3e9ad8360785b6c23c82dd3856df00732d9 drm-fixes-2024-08-02 drm-misc-fixes-2024-08-01 v6.11-rc2 Best regards Thomas > > Thanks! > -Qiuxu > > > -- -- Thomas Zimmermann Graphics Driver Developer SUSE Software Solutions Germany GmbH Frankenstrasse 146, 90461 Nuernberg, Germany GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman HRB 36809 (AG Nuernberg)