From: Akira Tsukamoto <akira.tsukamoto@gmail.com> To: Paul Walmsley <paul.walmsley@sifive.com>, Palmer Dabbelt <palmer@dabbelt.com>, Albert Ou <aou@eecs.berkeley.edu>, Akira Tsukamoto <akira.tsukamoto@gmail.com>, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org Subject: [PATCH v2 0/5] riscv: improving uaccess with logs from network bench Date: Sat, 19 Jun 2021 20:21:17 +0900 [thread overview] Message-ID: <5a5c07ac-8c11-79d3-46a3-a255d4148f76@gmail.com> (raw) Optimizing copy_to_user and copy_from_user. I rewrote the functions in v2, heavily influenced by Garry's memcpy function [1]. The functions must be written in assembler to handle page faults manually inside the function. With the changes, improves in the percentage usage and some performance of network speed in UDP packets. Only patching copy_user. Using the original memcpy. All results are from the same base kernel, same rootfs and same BeagleV beta board. Comparison by "perf top -Ue task-clock" while running iperf3. --- TCP recv --- * Before 40.40% [kernel] [k] memcpy 33.09% [kernel] [k] __asm_copy_to_user * After 50.35% [kernel] [k] memcpy 13.76% [kernel] [k] __asm_copy_to_user --- TCP send --- * Before 19.96% [kernel] [k] memcpy 9.84% [kernel] [k] __asm_copy_to_user * After 14.27% [kernel] [k] memcpy 7.37% [kernel] [k] __asm_copy_to_user --- UDP send --- * Before 25.18% [kernel] [k] memcpy 22.50% [kernel] [k] __asm_copy_to_user * After 28.90% [kernel] [k] memcpy 9.49% [kernel] [k] __asm_copy_to_user --- UDP recv --- * Before 44.45% [kernel] [k] memcpy 31.04% [kernel] [k] __asm_copy_to_user * After 55.62% [kernel] [k] memcpy 11.22% [kernel] [k] __asm_copy_to_user Processing network packets require a lot of unaligned access for the packet header, which is not able to change the design of the header format to be aligned. And user applications call system calls with a large buffer for send/recf() and sendto/recvfrom() to repeat less function calls for the optimization. v1 -> v2: - Added shift copy - Separated patches for readability of changes in assembler - Using perf results [1] https://lkml.org/lkml/2021/2/16/778 Akira Tsukamoto (5): riscv: __asm_to/copy_from_user: delete existing code riscv: __asm_to/copy_from_user: Adding byte copy first riscv: __asm_to/copy_from_user: Copy until dst is aligned address riscv: __asm_to/copy_from_user: Bulk copy while shifting misaligned data riscv: __asm_to/copy_from_user: Bulk copy when both src dst are aligned arch/riscv/lib/uaccess.S | 181 +++++++++++++++++++++++++++++++-------- 1 file changed, 146 insertions(+), 35 deletions(-) -- 2.17.1
WARNING: multiple messages have this Message-ID (diff)
From: Akira Tsukamoto <akira.tsukamoto@gmail.com> To: Paul Walmsley <paul.walmsley@sifive.com>, Palmer Dabbelt <palmer@dabbelt.com>, Albert Ou <aou@eecs.berkeley.edu>, Akira Tsukamoto <akira.tsukamoto@gmail.com>, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org Subject: [PATCH v2 0/5] riscv: improving uaccess with logs from network bench Date: Sat, 19 Jun 2021 20:21:17 +0900 [thread overview] Message-ID: <5a5c07ac-8c11-79d3-46a3-a255d4148f76@gmail.com> (raw) Optimizing copy_to_user and copy_from_user. I rewrote the functions in v2, heavily influenced by Garry's memcpy function [1]. The functions must be written in assembler to handle page faults manually inside the function. With the changes, improves in the percentage usage and some performance of network speed in UDP packets. Only patching copy_user. Using the original memcpy. All results are from the same base kernel, same rootfs and same BeagleV beta board. Comparison by "perf top -Ue task-clock" while running iperf3. --- TCP recv --- * Before 40.40% [kernel] [k] memcpy 33.09% [kernel] [k] __asm_copy_to_user * After 50.35% [kernel] [k] memcpy 13.76% [kernel] [k] __asm_copy_to_user --- TCP send --- * Before 19.96% [kernel] [k] memcpy 9.84% [kernel] [k] __asm_copy_to_user * After 14.27% [kernel] [k] memcpy 7.37% [kernel] [k] __asm_copy_to_user --- UDP send --- * Before 25.18% [kernel] [k] memcpy 22.50% [kernel] [k] __asm_copy_to_user * After 28.90% [kernel] [k] memcpy 9.49% [kernel] [k] __asm_copy_to_user --- UDP recv --- * Before 44.45% [kernel] [k] memcpy 31.04% [kernel] [k] __asm_copy_to_user * After 55.62% [kernel] [k] memcpy 11.22% [kernel] [k] __asm_copy_to_user Processing network packets require a lot of unaligned access for the packet header, which is not able to change the design of the header format to be aligned. And user applications call system calls with a large buffer for send/recf() and sendto/recvfrom() to repeat less function calls for the optimization. v1 -> v2: - Added shift copy - Separated patches for readability of changes in assembler - Using perf results [1] https://lkml.org/lkml/2021/2/16/778 Akira Tsukamoto (5): riscv: __asm_to/copy_from_user: delete existing code riscv: __asm_to/copy_from_user: Adding byte copy first riscv: __asm_to/copy_from_user: Copy until dst is aligned address riscv: __asm_to/copy_from_user: Bulk copy while shifting misaligned data riscv: __asm_to/copy_from_user: Bulk copy when both src dst are aligned arch/riscv/lib/uaccess.S | 181 +++++++++++++++++++++++++++++++-------- 1 file changed, 146 insertions(+), 35 deletions(-) -- 2.17.1 _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv
next reply other threads:[~2021-06-19 11:21 UTC|newest] Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-06-19 11:21 Akira Tsukamoto [this message] 2021-06-19 11:21 ` [PATCH v2 0/5] riscv: improving uaccess with logs from network bench Akira Tsukamoto 2021-06-19 11:34 ` [PATCH 1/5] riscv: __asm_to/copy_from_user: delete existing code Akira Tsukamoto 2021-06-19 11:34 ` Akira Tsukamoto 2021-06-21 11:45 ` David Laight 2021-06-21 11:45 ` David Laight 2021-06-21 13:55 ` Akira Tsukamoto 2021-06-21 13:55 ` Akira Tsukamoto 2021-06-19 11:35 ` [PATCH 2/5] riscv: __asm_to/copy_from_user: Adding byte copy first Akira Tsukamoto 2021-06-19 11:35 ` Akira Tsukamoto 2021-06-19 11:36 ` [PATCH 3/5] riscv: __asm_to/copy_from_user: Copy until dst is aligned Akira Tsukamoto 2021-06-19 11:36 ` Akira Tsukamoto 2021-06-19 11:37 ` [PATCH 4/5] riscv: __asm_to/copy_from_user: Bulk copy while shifting Akira Tsukamoto 2021-06-19 11:37 ` Akira Tsukamoto 2021-06-19 11:43 ` [PATCH 5/5] riscv: __asm_to/copy_from_user: Bulk copy when both src, dst are aligned Akira Tsukamoto 2021-06-19 11:43 ` Akira Tsukamoto 2021-06-21 11:55 ` David Laight 2021-06-21 11:55 ` David Laight 2021-06-21 14:13 ` Akira Tsukamoto 2021-06-21 14:13 ` Akira Tsukamoto 2021-06-20 10:02 ` [PATCH v2 0/5] riscv: improving uaccess with logs from network bench Ben Dooks 2021-06-20 10:02 ` Ben Dooks 2021-06-20 16:36 ` Akira Tsukamoto 2021-06-20 16:36 ` Akira Tsukamoto 2021-06-22 8:30 ` Ben Dooks 2021-06-22 8:30 ` Ben Dooks 2021-06-22 12:05 ` Akira Tsukamoto 2021-06-22 12:05 ` Akira Tsukamoto 2021-06-22 17:45 ` Ben Dooks 2021-06-22 17:45 ` Ben Dooks 2021-07-12 21:24 ` Ben Dooks 2021-07-12 21:24 ` Ben Dooks
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=5a5c07ac-8c11-79d3-46a3-a255d4148f76@gmail.com \ --to=akira.tsukamoto@gmail.com \ --cc=aou@eecs.berkeley.edu \ --cc=linux-kernel@vger.kernel.org \ --cc=linux-riscv@lists.infradead.org \ --cc=palmer@dabbelt.com \ --cc=paul.walmsley@sifive.com \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.