39dfe84451
Right now nvme_alloc_request() allocates a request from block layer based on the value of the qid. When qid set to NVME_QID_ANY it used blk_mq_alloc_request() else blk_mq_alloc_request_hctx(). The function nvme_alloc_request() is called from different context, The only place where it uses non NVME_QID_ANY value is for fabrics connect commands :- nvme_submit_sync_cmd() NVME_QID_ANY nvme_features() NVME_QID_ANY nvme_sec_submit() NVME_QID_ANY nvmf_reg_read32() NVME_QID_ANY nvmf_reg_read64() NVME_QID_ANY nvmf_reg_write32() NVME_QID_ANY nvmf_connect_admin_queue() NVME_QID_ANY nvme_submit_user_cmd() NVME_QID_ANY nvme_alloc_request() nvme_keep_alive() NVME_QID_ANY nvme_alloc_request() nvme_timeout() NVME_QID_ANY nvme_alloc_request() nvme_delete_queue() NVME_QID_ANY nvme_alloc_request() nvmet_passthru_execute_cmd() NVME_QID_ANY nvme_alloc_request() nvmf_connect_io_queue() QID __nvme_submit_sync_cmd() nvme_alloc_request() With passthru nvme_alloc_request() now falls into the I/O fast path such that blk_mq_alloc_request_hctx() is never gets called and that adds additional branch check in fast path. Split the nvme_alloc_request() into nvme_alloc_request() and nvme_alloc_request_qid(). Replace each call of the nvme_alloc_request() with NVME_QID_ANY param with a call to newly added nvme_alloc_request() without NVME_QID_ANY. Replace a call to nvme_alloc_request() with QID param with a call to newly added nvme_alloc_request() and nvme_alloc_request_qid() based on the qid value set in the __nvme_submit_sync_cmd(). Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Reviewed-by: Logan Gunthorpe <logang@deltatee.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.