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Diffstat (limited to '')
| -rw-r--r-- | debian/patches-rt/0319-Revert-mm-page_alloc-fix-potential-deadlock-on-zonel.patch | 63 |
1 files changed, 63 insertions, 0 deletions
diff --git a/debian/patches-rt/0319-Revert-mm-page_alloc-fix-potential-deadlock-on-zonel.patch b/debian/patches-rt/0319-Revert-mm-page_alloc-fix-potential-deadlock-on-zonel.patch new file mode 100644 index 000000000..1872b2fc8 --- /dev/null +++ b/debian/patches-rt/0319-Revert-mm-page_alloc-fix-potential-deadlock-on-zonel.patch @@ -0,0 +1,63 @@ +From 59fc9fa59a8a6eaa1456e7a3035b10152a9e6d94 Mon Sep 17 00:00:00 2001 +From: "Luis Claudio R. Goncalves" <lgoncalv@redhat.com> +Date: Thu, 8 Jun 2023 19:47:25 -0300 +Subject: [PATCH 319/323] Revert "mm/page_alloc: fix potential deadlock on + zonelist_update_seqseqlock" +Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/5.10/older/patches-5.10.204-rt100.tar.xz + +This reverts commit a992c387b41186ab968fd176ca26b432b05c53ec. + +The support for deferred printing was removed in v5.10-rc1-rt1 by commit +9153e3c5cb0c9 ("printk: remove deferred printing") because: + + Since printing occurs either atomically or from the printing + kthread, there is no need for any deferring or tracking possible + recursion paths. Remove all printk context tracking. + +Also, disabling interrupts in __build_all_zonelists() should produce warnings +once that code path is hit. + +Fixes: a992c387b4118 ("mm/page_alloc: fix potential deadlock on zonelist_update_seq seqlock") +Signed-off-by: Luis Claudio R. Goncalves <lgoncalv@redhat.com> +--- + mm/page_alloc.c | 16 ---------------- + 1 file changed, 16 deletions(-) + +diff --git a/mm/page_alloc.c b/mm/page_alloc.c +index c5eb7d6844ae..39d1782b398f 100644 +--- a/mm/page_alloc.c ++++ b/mm/page_alloc.c +@@ -6043,21 +6043,7 @@ static void __build_all_zonelists(void *data) + int nid; + int __maybe_unused cpu; + pg_data_t *self = data; +- unsigned long flags; + +- /* +- * Explicitly disable this CPU's interrupts before taking seqlock +- * to prevent any IRQ handler from calling into the page allocator +- * (e.g. GFP_ATOMIC) that could hit zonelist_iter_begin and livelock. +- */ +- local_irq_save(flags); +- /* +- * Explicitly disable this CPU's synchronous printk() before taking +- * seqlock to prevent any printk() from trying to hold port->lock, for +- * tty_insert_flip_string_and_push_buffer() on other CPU might be +- * calling kmalloc(GFP_ATOMIC | __GFP_NOWARN) with port->lock held. +- */ +- printk_deferred_enter(); + write_seqlock(&zonelist_update_seq); + + #ifdef CONFIG_NUMA +@@ -6092,8 +6078,6 @@ static void __build_all_zonelists(void *data) + } + + write_sequnlock(&zonelist_update_seq); +- printk_deferred_exit(); +- local_irq_restore(flags); + } + + static noinline void __init +-- +2.43.0 + |