From: Ingo Molnar <mingo@kernel.org>
To: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: linux-efi@vger.kernel.org, Thomas Gleixner <tglx@linutronix.de>,
linux-kernel@vger.kernel.org, Andy Lutomirski <luto@kernel.org>,
Arend van Spriel <arend.vanspriel@broadcom.com>,
Bhupesh Sharma <bhsharma@redhat.com>,
Borislav Petkov <bp@alien8.de>,
Dave Hansen <dave.hansen@intel.com>,
Eric Snowberg <eric.snowberg@oracle.com>,
Hans de Goede <hdegoede@redhat.com>,
Joe Perches <joe@perches.com>, Jon Hunter <jonathanh@nvidia.com>,
Julien Thierry <julien.thierry@arm.com>,
Marc Zyngier <marc.zyngier@arm.com>,
Nathan Chancellor <natechancellor@gmail.com>,
Peter Zijlstra <peterz@infradead.org>,
Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>,
Sedat Dilek <sedat.dilek@gmail.com>,
YiFei Zhu <zhuyifei1999@gmail.com>
Subject: Re: [PATCH 10/11] efi: reduce the amount of memblock reservations for persistent allocations
Date: Fri, 30 Nov 2018 09:38:23 +0100 [thread overview]
Message-ID: <20181130083823.GB97998@gmail.com> (raw)
In-Reply-To: <20181129171230.18699-11-ard.biesheuvel@linaro.org>
* Ard Biesheuvel <ard.biesheuvel@linaro.org> wrote:
> The current implementation of efi_mem_reserve_persistent() is rather
> naive, in the sense that for each invocation, it creates a separate
> linked list entry to describe the reservation. Since the linked list
> entries themselves need to persist across subsequent kexec reboots,
> every reservation created this way results in two memblock_reserve()
> calls at the next boot.
>
> On arm64 systems with 100s of CPUs, this may result in a excessive
> number of memblock reservations, and needless fragmentation.
>
> So instead, make use of the newly updated struct linux_efi_memreserve
> layout to put multiple reservations into a single linked list entry.
> This should get rid of the numerous tiny memblock reservations, and
> effectively cut the total number of reservations in half on arm64
> systems with many CPUs.
>
> Tested-by: Marc Zyngier <marc.zyngier@arm.com>
> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> ---
> drivers/firmware/efi/efi.c | 20 +++++++++++++++++---
> include/linux/efi.h | 3 +++
> 2 files changed, 20 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
> index 80b11521627a..e90bc32c2670 100644
> --- a/drivers/firmware/efi/efi.c
> +++ b/drivers/firmware/efi/efi.c
> @@ -998,7 +998,8 @@ int __ref efi_mem_reserve_persistent(phys_addr_t addr, u64 size)
> {
> struct linux_efi_memreserve *rsv;
> int rsvsize = EFI_MEMRESERVE_SIZE(1);
> - int rc;
> + unsigned long prsv;
> + int rc, index;
>
> if (efi_memreserve_root == (void *)ULONG_MAX)
> return -ENODEV;
> @@ -1009,11 +1010,24 @@ int __ref efi_mem_reserve_persistent(phys_addr_t addr, u64 size)
> return rc;
> }
>
> - rsv = kmalloc(rsvsize, GFP_ATOMIC);
I fixed the following build warning in this patch:
drivers/firmware/efi/efi.c:1000:6: warning: unused variable ‘rsvsize’ [-Wunused-variable]
'rsvsize' got entirely orphaned by the patch, so it can be removed.
Thanks,
Ingo
next prev parent reply other threads:[~2018-11-30 8:38 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-29 17:12 [GIT PULL 00/11] EFI updates Ard Biesheuvel
2018-11-29 17:12 ` [PATCH 01/11] x86/efi: Allocate e820 buffer before calling efi_exit_boot_service Ard Biesheuvel
2018-11-30 7:29 ` Ingo Molnar
2018-11-30 8:26 ` Ard Biesheuvel
2018-11-30 8:36 ` Ingo Molnar
2018-11-30 9:55 ` [tip:efi/core] " tip-bot for Eric Snowberg
2018-11-29 17:12 ` [PATCH 02/11] efi/fdt: Indentation fix Ard Biesheuvel
2018-11-30 7:56 ` [PATCH] efi/fdt: More cleanups Ingo Molnar
2018-11-30 8:31 ` Ard Biesheuvel
2018-11-30 9:48 ` Ingo Molnar
2018-11-30 9:56 ` [tip:efi/core] efi/fdt: Indentation fix tip-bot for Julien Thierry
2018-11-29 17:12 ` [PATCH 03/11] efi/fdt: Simplify get_fdt flow Ard Biesheuvel
2018-11-30 9:57 ` [tip:efi/core] efi/fdt: Simplify the get_fdt() flow tip-bot for Julien Thierry
2018-11-29 17:12 ` [PATCH 04/11] x86/mm/pageattr: Introduce helper function to unmap EFI boot services Ard Biesheuvel
2018-11-30 9:58 ` [tip:efi/core] " tip-bot for Sai Praneeth Prakhya
2018-11-29 17:12 ` [PATCH 05/11] x86/efi: Unmap EFI boot services code/data regions from efi_pgd Ard Biesheuvel
2018-11-30 9:58 ` [tip:efi/core] " tip-bot for Sai Praneeth Prakhya
2018-12-17 18:06 ` Prakhya, Sai Praneeth
2018-12-17 18:10 ` Ard Biesheuvel
2018-12-17 18:42 ` Prakhya, Sai Praneeth
2018-12-17 19:35 ` Ard Biesheuvel
2018-12-17 19:48 ` Prakhya, Sai Praneeth
2018-12-21 17:02 ` Ard Biesheuvel
2018-12-21 17:13 ` Borislav Petkov
2018-12-21 17:26 ` Ard Biesheuvel
2018-12-21 19:29 ` Borislav Petkov
2018-12-22 11:07 ` Ard Biesheuvel
2019-01-07 15:57 ` Matt Fleming
2018-12-21 17:52 ` Prakhya, Sai Praneeth
2018-11-29 17:12 ` [PATCH 06/11] x86/efi: Move efi_<reserve/free>_boot_services() to arch/x86 Ard Biesheuvel
2018-11-30 9:59 ` [tip:efi/core] " tip-bot for Sai Praneeth Prakhya
2018-11-29 17:12 ` [PATCH 07/11] efi/libstub: Disable some warnings for x86{,_64} Ard Biesheuvel
2018-11-30 9:59 ` [tip:efi/core] " tip-bot for Nathan Chancellor
2018-11-29 17:12 ` [PATCH 08/11] firmware: efi: add NULL pointer checks in efivars api functions Ard Biesheuvel
2018-11-30 8:11 ` Ingo Molnar
2018-11-30 8:37 ` Ard Biesheuvel
2018-11-30 9:56 ` [tip:efi/core] firmware/efi: Add NULL pointer checks in efivars API functions tip-bot for Arend van Spriel
2018-11-29 17:12 ` [PATCH 09/11] efi: permit multiple entries in persistent memreserve data structure Ard Biesheuvel
2018-11-30 10:00 ` [tip:efi/core] efi: Permit " tip-bot for Ard Biesheuvel
2018-11-29 17:12 ` [PATCH 10/11] efi: reduce the amount of memblock reservations for persistent allocations Ard Biesheuvel
2018-11-30 8:38 ` Ingo Molnar [this message]
2018-11-30 8:39 ` Ard Biesheuvel
2018-11-30 10:00 ` [tip:efi/core] efi: Reduce " tip-bot for Ard Biesheuvel
2018-11-29 17:12 ` [PATCH 11/11] efi/x86: earlyprintk - Fix infinite loop on some screen widths Ard Biesheuvel
2018-11-30 8:05 ` Ingo Molnar
2018-11-30 8:32 ` Ard Biesheuvel
2018-11-30 9:55 ` [tip:efi/core] x86/earlyprintk/efi: " tip-bot for YiFei Zhu
2018-11-29 18:27 ` [GIT PULL 00/11] EFI updates Prakhya, Sai Praneeth
2018-11-30 12:01 ` Ard Biesheuvel
2018-11-30 18:01 ` Prakhya, Sai Praneeth
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