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charset=us-ascii Content-Disposition: inline In-Reply-To: <20251001192647.195204-11-urezki@gmail.com> X-Scanned-By: MIMEDefang 3.0 on 10.30.177.12 X-Stat-Signature: wn6jm7fufwcjyyg6r9syknndxu3rgwci X-Rspam-User: X-Rspamd-Queue-Id: 6490140005 X-Rspamd-Server: rspam10 X-HE-Tag: 1759552642-235755 X-HE-Meta: U2FsdGVkX19hNGGV6WY+qLO1iNHpiMGQe4p2rnPmbDgOp6NznqAiPNKlCbBS2i7hNG58Ue1nzMKEJx2Z5ZwF6mmK3qBi6LOJxMK0bYvJXb4HwSsPqdSfL/sTPT9TN6nQZ9tJEEwBR9GGwg5zyl5CpqXqrn9PcW0DaHz99kb00bIuU9M5u1AkRxmxKzn+6SP6C+GcJmeoVKKMwU/RA+4e70bwPru4rHdGgz+Nqzhk+rlfkzWsaC1MP5s+6NLt2qYSyaFn2XYAD/4LpbwcTWylcqm3OVB1/yg6hcdcSHMwBQpAwOcZJeInwH6b+BdyYHKdd0ItR3nDYMwpzn4WJZ+YLzUtw/kNMQKjvZVx3pQAElzJ7ebQCva+Qmi7gr2Ac9uvD4sk8/I+FPFjQajtiqkGc3BQY0JgUBfAmqApKYiYreez6aRrOhj4+AvGQOChckysoTjlEaA7ivvn+pf9yLiznVBJuuHpSHDikGWMcGbwb+dE4GqmNX0Q6+jlUdQmgYQTVw6VcYZKR2XAxQaj2wbMG32AV3SG8C96Wl6MXNeMDIjK65fa+Ksjita0kRm4glH00qx6VTMtdCflmJyHE9Ut2jDAiEfUSyUZfq14gMcxUwqxd2qtqpx/vBAmCZn647U3n+yTJSYxUWmOi5qU/o6XkaWmQn8+nY768Cg/6qwsDhrhb6PDh85IWChmFRL2WOXCNJxsG6svEk8R7z+9hot8CU8c4wLWCUbXnuYPWnILGMEbH7h2NkYVQYTSUbdvpWrDBkaRL2iyR4ihJIK1laTJexDh/rpMbyOlV/IDuHCV8HXOtfKROGLMhiRDsTmXhHhX7O5h73fk8GhHV7JGNRCvH2l1d86p0fiS+ZEmk+SBtcgG7XIUwOuGwPItP3QfPm2tkYjOeG/Bt2XbT3g9s+PyU3fH+73rf3QM55IeMrz45dK2AzQYO34g/8Uv3sKB10ZyZ/blFEYupCL/YRWP9aF yolmmG5M VGM2f4mQe18jBLATxDqVKc1/94P9u3vN9yZIiMja/RAJAxLuNqeodfsFORM2x1LUNR6OI9d//2DSdEqz8vsDJyOksjiQq0Ek0KQjFDknpietm9URup3vG9niP/zOcMiIbhRJ8tWdG/UDM60YUaOR6apFY+ROw/RJor2d3aLeYWYnoTds/Yc8q5otxWAgjehTmxb/VLwLUUwzjNfwSlC6FXNmdeogtgQXZ63uW7JYLSm566XN6PpXJ+jqrdABHk4feOnCh7qTAp3J8WUq0MMI7NdCVOAuezDY5FRpGGrVYMIATdqvz9owPkL5wqIGBljpTzgZjSIzzxbCT1Z2nUgZBV8iJjkwbGzD9Iuc0VL+l9cGRi/sCA3yRlPBphZenTcKDQzm2M36JGbf5mKG/naZWPnSN10GqVImTBQzqg588xj9Oy4yqlD9lUYtgyg390Uup8VIH X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 10/01/25 at 09:26pm, Uladzislau Rezki (Sony) wrote: > Extend __kvmalloc_node_noprof() to handle non-blocking GFP flags > (GFP_NOWAIT and GFP_ATOMIC). Previously such flags were rejected, > returning NULL. With this change: > > - kvmalloc() can fall back to vmalloc() if non-blocking contexts; > - for non-blocking allocations the VM_ALLOW_HUGE_VMAP option is > disabled, since the huge mapping path still contains might_sleep(); > - documentation update to reflect that GFP_NOWAIT and GFP_ATOMIC > are now supported. > > Signed-off-by: Uladzislau Rezki (Sony) > --- > mm/slub.c | 19 +++++++++++++------ > 1 file changed, 13 insertions(+), 6 deletions(-) Reviewed-by: Baoquan He > > diff --git a/mm/slub.c b/mm/slub.c > index 584a5ff1828b..3de0719e24e9 100644 > --- a/mm/slub.c > +++ b/mm/slub.c > @@ -7018,7 +7018,7 @@ static gfp_t kmalloc_gfp_adjust(gfp_t flags, size_t size) > * Uses kmalloc to get the memory but if the allocation fails then falls back > * to the vmalloc allocator. Use kvfree for freeing the memory. > * > - * GFP_NOWAIT and GFP_ATOMIC are not supported, neither is the __GFP_NORETRY modifier. > + * GFP_NOWAIT and GFP_ATOMIC are supported, the __GFP_NORETRY modifier is not. > * __GFP_RETRY_MAYFAIL is supported, and it should be used only if kmalloc is > * preferable to the vmalloc fallback, due to visible performance drawbacks. > * > @@ -7027,6 +7027,7 @@ static gfp_t kmalloc_gfp_adjust(gfp_t flags, size_t size) > void *__kvmalloc_node_noprof(DECL_BUCKET_PARAMS(size, b), unsigned long align, > gfp_t flags, int node) > { > + bool allow_block; > void *ret; > > /* > @@ -7039,16 +7040,22 @@ void *__kvmalloc_node_noprof(DECL_BUCKET_PARAMS(size, b), unsigned long align, > if (ret || size <= PAGE_SIZE) > return ret; > > - /* non-sleeping allocations are not supported by vmalloc */ > - if (!gfpflags_allow_blocking(flags)) > - return NULL; > - > /* Don't even allow crazy sizes */ > if (unlikely(size > INT_MAX)) { > WARN_ON_ONCE(!(flags & __GFP_NOWARN)); > return NULL; > } > > + /* > + * For non-blocking the VM_ALLOW_HUGE_VMAP is not used > + * because the huge-mapping path in vmalloc contains at > + * least one might_sleep() call. > + * > + * TODO: Revise huge-mapping path to support non-blocking > + * flags. > + */ > + allow_block = gfpflags_allow_blocking(flags); > + > /* > * kvmalloc() can always use VM_ALLOW_HUGE_VMAP, > * since the callers already cannot assume anything > @@ -7056,7 +7063,7 @@ void *__kvmalloc_node_noprof(DECL_BUCKET_PARAMS(size, b), unsigned long align, > * protection games. > */ > return __vmalloc_node_range_noprof(size, align, VMALLOC_START, VMALLOC_END, > - flags, PAGE_KERNEL, VM_ALLOW_HUGE_VMAP, > + flags, PAGE_KERNEL, allow_block ? VM_ALLOW_HUGE_VMAP:0, > node, __builtin_return_address(0)); > } > EXPORT_SYMBOL(__kvmalloc_node_noprof); > -- > 2.47.3 >