From: Eric Dumazet <eric.dumazet@gmail.com>
To: Indan Zupancic <indan@nul.nu>
Cc: Will Drewry <wad@chromium.org>,
linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org,
linux-doc@vger.kernel.org, kernel-hardening@lists.openwall.com,
netdev@vger.kernel.org, x86@kernel.org, arnd@arndb.de,
davem@davemloft.net, hpa@zytor.com, mingo@redhat.com,
oleg@redhat.com, peterz@infradead.org, rdunlap@xenotime.net,
mcgrathr@chromium.org, tglx@linutronix.de, luto@mit.edu,
eparis@redhat.com, serge.hallyn@canonical.com, djm@mindrot.org,
scarybeasts@gmail.com, pmoore@redhat.com,
akpm@linux-foundation.org, corbet@lwn.net, markus@chromium.org,
coreyb@linux.vnet.ibm.com, keescook@chromium.org
Subject: Re: [PATCH] net: bpf_jit: Simplify code by always using offset8 or offset32.
Date: Mon, 19 Mar 2012 19:59:46 -0700 [thread overview]
Message-ID: <1332212386.22737.20.camel@edumazet-glaptop> (raw)
In-Reply-To: <371a1925e68e68f873e30381e0fa60ea.squirrel@webmail.greenhost.nl>
On Tue, 2012-03-20 at 13:24 +1100, Indan Zupancic wrote:
> If it does then perhaps the fast path should be made faster by inlining
> the code instead of calling a function which may not be cached.
>
inlining 400 times a sequence of code is waste of icache, you probably
missed this.
I spent a lot of time on working on this implementation, tried many
different strategies before choosing the one in place.
Listen, I am tired of this thread, it seems you want to push changes
that have almost no value but still need lot of review.
Unless you make benchmarks and can make at least 5 % improvement of the
speed, or improve maintainability of this code, I am not interested.
We certainly _can_ one day have sizeof(struct sk_buff) > 256, and actual
code is ready for this. You want to break this for absolutely no valid
reason.
We _can_ change fields order anytime in struct sk_buff, even if you
state "its very unlikely that those fields are ever moved to the end
of sk_buff".
next prev parent reply other threads:[~2012-03-20 2:59 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-03-12 21:28 [PATCH v14 01/13] sk_run_filter: add BPF_S_ANC_SECCOMP_LD_W Will Drewry
2012-03-12 21:28 ` [PATCH v14 02/13] net/compat.c,linux/filter.h: share compat_sock_fprog Will Drewry
2012-03-12 21:28 ` [PATCH v14 03/13] seccomp: kill the seccomp_t typedef Will Drewry
2012-03-12 21:28 ` [PATCH v14 04/13] arch/x86: add syscall_get_arch to syscall.h Will Drewry
2012-03-12 21:28 ` [PATCH v14 05/13] asm/syscall.h: add syscall_get_arch Will Drewry
2012-03-12 21:28 ` [PATCH v14 06/13] seccomp: add system call filtering using BPF Will Drewry
2012-03-13 3:33 ` Indan Zupancic
2012-03-13 15:57 ` [kernel-hardening] " Will Drewry
2012-03-12 21:28 ` [PATCH v14 07/13] signal, x86: add SIGSYS info and make it synchronous Will Drewry
2012-03-12 21:28 ` [PATCH v14 08/13] seccomp: add SECCOMP_RET_ERRNO Will Drewry
2012-03-12 21:28 ` [PATCH v14 09/13] seccomp: Add SECCOMP_RET_TRAP Will Drewry
2012-03-12 21:28 ` [PATCH v14 10/13] ptrace,seccomp: Add PTRACE_SECCOMP support Will Drewry
2012-03-14 7:31 ` Indan Zupancic
2012-03-14 15:03 ` [kernel-hardening] " Will Drewry
2012-03-14 15:52 ` Will Drewry
2012-03-15 20:31 ` [PATCH v16 11/13] " Will Drewry
2012-03-12 21:28 ` [PATCH v14 11/13] x86: Enable HAVE_ARCH_SECCOMP_FILTER Will Drewry
2012-03-12 21:28 ` [PATCH v14 12/13] Documentation: prctl/seccomp_filter Will Drewry
2012-03-12 21:28 ` [PATCH v14 13/13] seccomp: remove duplicated failure logging Will Drewry
2012-03-13 3:40 ` [PATCH v14 01/13] sk_run_filter: add BPF_S_ANC_SECCOMP_LD_W Indan Zupancic
2012-03-13 15:40 ` Will Drewry
2012-03-13 10:04 ` Indan Zupancic
2012-03-13 15:43 ` Will Drewry
2012-03-13 17:13 ` Eric Dumazet
2012-03-14 5:12 ` Indan Zupancic
2012-03-14 5:55 ` Eric Dumazet
2012-03-14 7:59 ` Indan Zupancic
2012-03-14 8:05 ` Eric Dumazet
2012-03-17 10:14 ` Indan Zupancic
2012-03-17 13:49 ` Eric Dumazet
2012-03-18 8:35 ` Indan Zupancic
2012-03-18 12:40 ` [PATCH] net: bpf_jit: fix BPF_S_LDX_B_MSH compilation Eric Dumazet
2012-03-19 21:42 ` David Miller
2012-03-20 0:16 ` [PATCH] net: bpf_jit: Document evilness of negative indirect loads Indan Zupancic
2012-03-18 12:52 ` [PATCH v14 01/13] sk_run_filter: add BPF_S_ANC_SECCOMP_LD_W Eric Dumazet
2012-03-20 2:24 ` [PATCH] net: bpf_jit: Simplify code by always using offset8 or offset32 Indan Zupancic
2012-03-20 2:59 ` Eric Dumazet [this message]
2012-03-20 11:33 ` Indan Zupancic
2012-03-20 11:41 ` David Laight
2012-03-20 13:56 ` Eric Dumazet
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