From: Gao Xiang <hsiangkao@linux.alibaba.com>
To: Chunhai Guo <guochunhai@vivo.com>, xiang@kernel.org
Cc: linux-erofs@lists.ozlabs.org, huyue2@coolpad.com
Subject: Re: [PATCH] erofs: do not use pagepool in z_erofs_gbuf_growsize()
Date: Tue, 2 Apr 2024 16:57:29 +0800 [thread overview]
Message-ID: <b904fbcd-653d-4548-b354-213f5c4563ea@linux.alibaba.com> (raw)
In-Reply-To: <20240402084031.2623314-1-guochunhai@vivo.com>
On 2024/4/2 16:40, Chunhai Guo wrote:
> Let's use alloc_pages_bulk_array() for simplicity and get rid of
> unnecessary pagepool.
>
> Signed-off-by: Chunhai Guo <guochunhai@vivo.com>
> ---
> fs/erofs/zutil.c | 64 +++++++++++++++++++++++-------------------------
> 1 file changed, 30 insertions(+), 34 deletions(-)
>
> diff --git a/fs/erofs/zutil.c b/fs/erofs/zutil.c
> index e13806681763..14440c0bf64e 100644
> --- a/fs/erofs/zutil.c
> +++ b/fs/erofs/zutil.c
> @@ -60,61 +60,57 @@ void z_erofs_put_gbuf(void *ptr) __releases(gbuf->lock)
> int z_erofs_gbuf_growsize(unsigned int nrpages)
> {
> static DEFINE_MUTEX(gbuf_resize_mutex);
> - struct page *pagepool = NULL;
> - int delta, ret, i, j;
> + struct page **tmp_pages = NULL;
> + struct z_erofs_gbuf *gbuf;
> + void *ptr, *old_ptr;
> + int last, i, j;
> + int ret = 0；
no needed.
>
> mutex_lock(&gbuf_resize_mutex);
> - delta = nrpages - z_erofs_gbuf_nrpages;
> - ret = 0;
> /* avoid shrinking gbufs, since no idea how many fses rely on */
> - if (delta <= 0)
> + if (nrpages <= z_erofs_gbuf_nrpages)
> goto out;
if (nrpages <= z_erofs_gbuf_nrpages) {
mutex_unlock(&gbuf_resize_mutex);
return 0;
}
since it's a fast side path, let's bail out this directly.
>
> + ret = -ENOMEM;
no needed.
> for (i = 0; i < z_erofs_gbuf_count; ++i) {
> - struct z_erofs_gbuf *gbuf = &z_erofs_gbufpool[i];
> - struct page **pages, **tmp_pages;
> - void *ptr, *old_ptr = NULL;
> -
> - ret = -ENOMEM;
> + gbuf = &z_erofs_gbufpool[i];
> tmp_pages = kcalloc(nrpages, sizeof(*tmp_pages), GFP_KERNEL);
> if (!tmp_pages)
> - break;
> - for (j = 0; j < nrpages; ++j) {
> - tmp_pages[j] = erofs_allocpage(&pagepool, GFP_KERNEL);
> - if (!tmp_pages[j])
> - goto free_pagearray;
> - }
> + goto out;
> +
> + for (j = 0; j < gbuf->nrpages; ++j)
> + tmp_pages[j] = gbuf->pages[j];
> + do {
> + last = j;
> + j = alloc_pages_bulk_array(GFP_KERNEL, nrpages,
> + tmp_pages);
> + if (last == j)
> + goto out;
> + } while (j != nrpages);
> +
> ptr = vmap(tmp_pages, nrpages, VM_MAP, PAGE_KERNEL);
> if (!ptr)
> - goto free_pagearray;
> + goto out;
>
> - pages = tmp_pages;
> spin_lock(&gbuf->lock);
> + kfree(gbuf->pages);
> + gbuf->pages = tmp_pages;
> old_ptr = gbuf->ptr;
> gbuf->ptr = ptr;
> - tmp_pages = gbuf->pages;
> - gbuf->pages = pages;
> - j = gbuf->nrpages;
> gbuf->nrpages = nrpages;
> spin_unlock(&gbuf->lock);
> - ret = 0;
> - if (!tmp_pages) {
> - DBG_BUGON(old_ptr);
> - continue;
> - }
> -
> if (old_ptr)
> vunmap(old_ptr);
> -free_pagearray:
> - while (j)
> - erofs_pagepool_add(&pagepool, tmp_pages[--j]);
> - kfree(tmp_pages);
> - if (ret)
> - break;
> }
> + ret = 0;
> z_erofs_gbuf_nrpages = nrpages;
> - erofs_release_pages(&pagepool);
> out:
> + if (ret && tmp_pages) {
if (i < z_erofs_gbuf_count && tmp_pages) {
> + for (j = 0; j < nrpages; ++j)
> + if (tmp_pages[j] && tmp_pages[j] != gbuf->pages[j])
> + __free_page(tmp_pages[j]);
> + kfree(tmp_pages);
> + }
> mutex_unlock(&gbuf_resize_mutex);
> return ret;
return i < z_erofs_gbuf_count ? -ENOMEM: 0;
Otherwise it looks good to me.
Thanks,
Gao Xiang
> }
prev parent reply other threads:[~2024-04-02 8:57 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-02 8:40 [PATCH] erofs: do not use pagepool in z_erofs_gbuf_growsize() Chunhai Guo via Linux-erofs
2024-04-02 8:57 ` Gao Xiang [this message]
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